# Fuel Trim Information



## [email protected] (Jun 5, 2002)

Some of the most common fault codes (DTC's) pertain to fuel trim. Here is an explanation of fuel trim and what it does for us.
The ECU controls Air/Fuel mixture in order to maintain power, efficiency, and emissions. A/F is expressed as either a ratio (14.7:1 for example) or as a Lambda value. With iso-octane ("ideal" gasoline), Lambda of 1.0 is equal to 14.7:1 A/F. This is known as "Stoichiometric", a condition where there is a perfect balance between oxygen molecules and the various hydrogen and carbon based molecules in petroleum. With the oxygenated gasoline that most of us use, actual A/F ratio of 15:1 is closer to stoichiometric. 
If Lambda is greater than 1.0, then there is a surplus of air and the engine is running lean. If Lambda is less than 1.0, then there is a surplus of fuel and the engine is running rich. It should be noted that the ratios are mass-based, not volume-based. 
So, why don't we always run at 1.0 all the time? Well, we do MOST of the time. At cruise and idle, mixture is held tightly to 1.0 to keep the catalytic convertor at optimal efficiency, so the emissions are minimized. However, when we need acceleration, the mixture gets richer. Why? Maximum power is made between 0.85 to 0.95 Lambda (12.5 to 14.0 A/F with iso-octane). So, under acceleration, mixtures get richer. Sometimes you want to get even richer under acceleration to keep detonation (pre-ignition of the mixture from excess cylinder temperatures) away. The 1.8T, for example, has a relatively high compression ratio for a turbocharged engine, which especially under lots of boost, is very succeptible to detonation). 
So, now that we know that the ECU wants to be able to control the A/F ratio. It has a prescribed set of values (maps) for a given RPM, Load, etc. So, the ECU tells the injectors to pulse for exactly XX.X milliseconds and that SHOULD get us the proper A/F ratio that we want. Well, if you tell an employee to go do something, you want to make sure they actually did it, right? The ECU has some snitches (the front O2 sensor and the MAF, for the most part) that will report back whether or not the desired mixture has been attained. The rear O2 sensor is used mostly to monitor the condition of the catalytic convertor, although in some applications it also contributes to trim information. 
Based on feedback from the snitches, the ECU learns to apply a correction factor to its commands to the fuel injectors. If you know that your employees take longer than the standard allotted time to do a specified job, you will need to adjust for that in your planning (injectors are in a union, so it is tough to fire them ). The learned values go between the maps in the ECU's Flash ROM (the "chip") and the signal to the fuel injectors. These learned compensations are known as "trim". So, when you see "trim", it means "compensation". 
"Add" means additive trim, which is addressing an imbalance at idle. When the ECU is using additive trim, it is telling the injectors to stay open a fixed amount longer or shorter. The malfunction (e.g. vacuum leak) becomes less significant as RPM increase. For additive adaptation values, the injection timing is changed by a fixed amount. This value is not dependent on the basic injection timing. 
"Mult" mean multiplicative trim, which is addressing an imbalance at all engine speeds. The malfunction (e.g. clogged injector) becomes more severe at increased RPM. For multiplicative adaptation values, there is a percentage change in injection timing. This change is dependent on the basic injection timing. 
You can check your current state of trim by using VAG-COM or equivalent to look in Group 032 in your engine measuring blocks. The first two fields will have percentages. The first field tells the fuel trim at idle (Additive). The second field tells the fuel trim at elevated engine speeds (Multiplicative). Negative values indicate that the engine is running too rich and oxygen sensor control is therefore making it more lean by reducing the amount of time that the injectors are open. Positive values indicate that the engine is running too lean and oxygen sensor control is therefore making it richer by increasing the amount of time that the injectors are open.

It is totally normal for both the first and second fields to be something other than zero. In fact, zeros indicate either you just cleared codes (which will reset fuel trim values) or something isn't working properly. If values get too far away from zero, it will cause a DTC (fault code) and can set off the MIL (commonly referred to as the Check Engine Light, or CEL). 
Specifications for normal operation are usually somewhere near +/- 10%. 
In general, an out-of-spec value in the first field (Additive) indicates a vacuum leak since it is mostly present at idle, when vacuum is highest. An out-of-spec value in the second field (Multiplicative) indicates a fault at higher RPM, and may point to a faulty MAF. 
Here's a good sanity check for the status of your MAF. Do a full-throttle run all the way to redline in a single gear (second works fine). Group 002 usually shows air mass in g/s. Your peak airflow should be roughly 0.80 times your horsepower. So, if you have a stock 150 hp 1.8T, expect around 120 g/s. If you have a 201 hp 24V VR6, expect around 160 g/s. If you see significantly less than that, you MAF may be on the way out. This still works if you are chipped, but "race" programs may make more power through timing, rather than airflow. Therefore, take all readings with a grain of salt.


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## MastaVR6 (Jun 10, 2003)

WOW, a forum with good information...
and yes, I do (HEX/)VAG-COM, thank you very much, why do you ask?
u said trim.








(obviously from the MkIV forum)


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## Junk T.I. (Sep 18, 2003)

*Re: (MastaVR6)*

awesome write up andy.........
explained well.


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## Taddd (Jan 1, 2004)

Appreciate it! http://****************.com/smile/emthup.gif


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## FrankiEBoneZ (Jun 4, 2002)

*Re: (Taddd)*

That is some useful info.


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## [email protected] (Jun 5, 2002)

*Re: (FrankiEBoneZ)*

Glad you guys like it. You do realize this same text has been in the 1.8T forum FAQ for over a year.


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## stuex (Feb 18, 2001)

Yup, saw it in the 1.8T faq.. but making it a sticky here would be good.


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## ben_dawg (Jan 22, 2004)

*Re: Fuel Trim Information ([email protected])*

Wow... Nice! Good info to have considering I have a car at the Stealer right now for the O2 recall, and it threw a multiplicative this weekend.
Holy timing, Batman - all this info, and I just stumbled upon the Vortex last week...


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## Junk T.I. (Sep 18, 2003)

*Re: Fuel Trim Information (ben_dawg)*

also another way to reassure whether a maf is on the way out or is bad is to check block 006.....
usually I see this reading anywhere from plus or minus 3.1%
anything higher than this within reason could confirm a bad MAF.
best thing to do is to check this block when you know your maf is good and then use that as a base line reading.....
this is basically an atmospheric or barometer reading..... it can vary, but as I said before, within reason
different altitudes will of course give different readings, as well as different humidity measures
Pat


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## fccn75 (Aug 18, 2003)

*Re: Fuel Trim Information (Junk T.I.)*

Very interesting http://****************.com/smile/emthup.gif , will you please elaborate on block 006? What is it's main parameters? 
What does that figure (atmospheric barometer) you gave +,- 3% relate to? 
Don't flame, I'm still a nooooobie but learning hella lot in this and the technical forum.
TIA


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information ([email protected])*

Andy
Is it possible to read fuel trim on AGU engines?
I suppose ECUs as mine also have this adaptive feature, please let me know.... http://****************.com/smile/emthup.gif


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## cshiflett (May 29, 2004)

*Re: Fuel Trim Information (27psiBoom)*

Andy!
http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
Two thumbs up! You should write a book.
This was some great information and extremely relevant on a recent problem I had.


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## mcgregor32000 (Jul 30, 2004)

*Re: Fuel Trim Information ([email protected])*

Andy thank I just got my new Vag-com from you so I will check it out
thanks
larry mc gregor


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## Lotust (Apr 5, 2002)

*Re: Fuel Trim Information (mcgregor32000)*

Hello,
I just ran the vag com beacuase i keep getting the "1 DTC's Found:
17536 - Fuel Trim: Bank 1 (Mult): System too Lean
35-00 - -" code 

the first Lambda value was -8.6

the second Lambda value was 24.2

I read this thread but i dont understand it fully. can anyone help me. I can send you the logs i took.


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information (Lotust)*

Increase secondary and decrease primary fuel tweek with lemmiwinks until you get closer to zero values, reset fuel trims before made any changes.


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## Lotust (Apr 5, 2002)

*Re: Fuel Trim Information (27psiBoom)*


_Quote, originally posted by *27psiBoom* »_Increase secondary and decrease primary fuel tweek with lemmiwinks until you get closer to zero values, reset fuel trims before made any changes.

huh ? is there a how2 for this? 
thanks http://****************.com/smile/emthup.gif


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## o2bad455 (Aug 22, 2003)

*Re: Fuel Trim Information ([email protected])*

Great info, but I might have spotted one error.
[email protected] said:
"With the oxygenated gasoline that most of us use, actual A/F ratio of 15:1 is closer to stoichiometric."
That doesn't sound right to me. If the fuel is "oxygenated", then it carries some of its own oxygen. Thus, while stoich for the standard fuel is an A/F mass ratio of 14.7:1, stoich for the oxygenated fuel should be slightly less (such as 14.5:1) since LESS external oxygen is required. Make sense?


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## digitalhippie (Apr 21, 2004)

*Re: Fuel Trim Information (Lotust)*


_Quote, originally posted by *Lotust* »_Hello,
I just ran the vag com beacuase i keep getting the "1 DTC's Found:
17536 - Fuel Trim: Bank 1 (Mult): System too Lean
35-00 - -" code 

the first Lambda value was -8.6

the second Lambda value was 24.2

I read this thread but i dont understand it fully. can anyone help me. I can send you the logs i took. 


Sounds like a bad MAF.


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information (digitalhippie)*

first channel is idle fuel trim (additive), second one is run fuel trim (multiplicative), you have problems with both of them....
they mean yur running too rich on idle and too lean on part throttle.
do you have a stock turbo?, what software are you running?, did you change any values with lemmiwinks?
You may have a faulty maf but I'd check the first O2 sensor first


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## genikz (Dec 7, 2001)

*Re: Fuel Trim Information ([email protected])*

I read this in the nick of time...I just calculated the worst mileage i've ever seen in my 1.8t (20mpg). Now where is that VAG-COM cable?
Thanks Andy!


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## AbqVR6 (Dec 29, 2001)

*Re: Fuel Trim Information (genikz)*

andy, i sent you an IM
max


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (digitalhippie)*


_Quote, originally posted by *digitalhippie* »_

Sounds like a bad MAF.


I agree. A multiplicative fuel trim close to the max value of 25% usually means the MAF is dead on a MKIV.
Gary


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## Mosquito (Mar 8, 2003)

Fuel trims of 1.7 and 2.3 are pretty normal, so they shouldn't need much adjustment correct?


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## VgRt6 (Mar 8, 2002)

*Re: (Mosquito)*


_Quote, originally posted by *Mosquito* »_Fuel trims of 1.7 and 2.3 are pretty normal, so they shouldn't need much adjustment correct?

Those values are completely normal. What do you mean by "shouldn't need much adjustment"? The trim IS the adjustment.
Gary


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## Mosquito (Mar 8, 2003)

*Re: (VgRt6)*

I meant I have no need to mess around with it.
BTW. would you happen to know if the breather hose connected to the side of the air box goes to the distributor cap? I have no idea why it would, but that's what it looks like. 
It just so happens that I have that hose connected to the CAI directly and I got some water in there a little while back. behavior has been better since I changed the oil recently, but it just crossed my mind that water could have gotten in that hose too. I'm looking to clean it if possible.










_Modified by Mosquito at 5:25 PM 2-12-2005_


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## VgRt6 (Mar 8, 2002)

*Re: (Mosquito)*

There's no need to mess with it ever, unless the fuel trims are excessive, indicating that the MAF might be fried and needs to be replaced. The ECU takes care of all of the adjustments and notes the adjustments in Block 032 for reference. Your values indicate that very little adjustment is needed to keep a stoichometric A:F mixture when the engine is both idling and at elevated RPMs.
That breather hose should connect the airbox to the secondary air injection system. Disconnect the hose at both ends and see if anything is still in there. Probably not if everything is running OK.
Gary


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## Mosquito (Mar 8, 2003)

*Re: (VgRt6)*

Thats probably ok then. Its just that I feel my car bogged down most of the time and I get sub chipped performace out of it with only 220+ miles to the tank and I've looked at so many things I don't know where to look anymore. sigh.
thanks though. http://****************.com/smile/emthup.gif


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## Johnny Blaze (Oct 18, 1999)

*Re: Fuel Trim Information ([email protected])*

great write up Andy as I am working on a fueling issue on my BT setup.. my fuel trims were at 6% and 25% on my readings last night from my VAG. Replacing my O2 sensor saturday morning and resetting everything.. hope this will clear up.. with a bit of lemmiwinks..














http://****************.com/smile/emthup.gif


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (Johnny Blaze)*

Don't bother replacing the O2 sensor just yet. Yout trim values indicate that the MAF is dead. I'd repalce it first and then recheck your fuel trims. They should be back i nthe normal range with a new MAF.
Gary


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## Johnny Blaze (Oct 18, 1999)

*Re: Fuel Trim Information (VgRt6)*

I am actually going to make an attempt to run no MAF and see how the car responds.. still going to replace the o2 sensor since I got some codes coming back "front o2 sensor low performance"


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (Johnny Blaze)*

FYI, bad MAFs have been known to trigger false O2 sensor codes on the MKIV cars. It's possible that replacing the MAF will eliminate the O2 sensor code. If you've already purchased the O2 sensor, then go ahead and change it. If not, I'd wait until after the MAF issue is resolved before buying the O2.
Gary


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## Johnny Blaze (Oct 18, 1999)

*Re: Fuel Trim Information (VgRt6)*

I already have the new o2 sensor.. bought it last week just to be safe.. with fuel trims at 6% and 25%.. what could something like indicate? I have heard that earlier model ECUs and engines relied more on the O2 sensors then the MAF for calculating fuel trims.. alot of people are running no MAF these days.. leaving it unplugged.. what are the adverse effects of doing this? if my fuel trims are dialed in good will I still need to it plugged in?
Also I thought maybe I had a vacuum leak somewhere as well.. its hard to resolve these problems though until I start at the source.. 
Chris


_Modified by Johnny Blaze at 2:36 PM 3-10-2005_


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (Johnny Blaze)*

The max. value that the fuel trim can be is 25%. If it's actually at 25%, that usually means the trim is maxed out and the needed correction is probably even greater. It would take a fairly large air leak to cause something like that. The most likely culprit is the MAF. EVERY single case that I know about where a multiplicative trim (the second one) of 25% was reported, the MAF was dead.
The source is the MAF. Replace that and all will be good. I literally did this on my sister's 1.8T two weeks ago. Mult. trim was 25% and there was an O2 sensor code. I replaced the MAF, the mult trim went to -5.5% (slightly rich) and the O2 code disappeared. The same exact thing happened on my VR6 back in '03. A new MAF fixed it then as well. 
Gary


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## Johnny Blaze (Oct 18, 1999)

*Re: Fuel Trim Information (VgRt6)*

did you end up using lemmiwinks to tune her adaption levels closer to zero?


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (Johnny Blaze)*

Nope. Just left them were they were. I don't see why you would want to change the trims. The trims are a correction. If you change the correction, then the solution is being circumvented. For example, if the engine is running rich for some reason (e.g., leaky injectors), you'll get a (-) trim so that the engine runs a stoichometric mixture. If you alter the trim back to zero, then the engine is running rich again. You should really fix the root cause of the problem, instead of fudging the fudge factor.
Gary


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## Johnny Blaze (Oct 18, 1999)

*Re: Fuel Trim Information (VgRt6)*

Well I am running REVO BT.. with a set of 440s and a VR6 maf.. so this isnt a stock setup... I also removed my airbox, ITG foam filter and a 3" TIP going to a GT2871R.. so some tuning might be needed here. REVO BT programming has been known to have some rich conditions at idle as well as WOT.. so some dialing in might be required as I know a few who have had to do it. However alot of people have setups where they are running no MAF at all..








I am going to try to root out the possiblities here.. as it can be anything at this point.. but im gonna check out the MAF and o2 sensor to see what happens this weekend. I am pulling my intake manifold off in a week to get it polished







. I will get new seats for my fuel injectors.. and see what I can do about replacing some of the hoses underneath and check for any vacuum leaks.. so I have a bunch of things going on.. guess this is what happens when you do a BT upgrade.. car becomes a big money pit..


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (Johnny Blaze)*

Good luck with everything and let us know what happens. http://****************.com/smile/emthup.gif








Gary


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information (VgRt6)*


_Quote, originally posted by *VgRt6* »_Nope. Just left them were they were. I don't see why you would want to change the trims. The trims are a correction. If you change the correction, then the solution is being circumvented. For example, if the engine is running rich for some reason (e.g., leaky injectors), you'll get a (-) trim so that the engine runs a stoichometric mixture. If you alter the trim back to zero, then the engine is running rich again. You should really fix the root cause of the problem, instead of fudging the fudge factor.
Gary

Great advice!!! http://****************.com/smile/emthup.gif 
But don't forget people who play with lemmiwinks run BT setups (maf housings, injectors, software combos) so they could actually run lean or rich at part thottle or idle, so this trim tweak could correct fueling to a proper level.
On a stock car lemmiwinks is not a good idea AT ALL, in this case people should look for the culprit of the problem as you properly stated. http://****************.com/smile/emthup.gif


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## [email protected] (Oct 24, 2002)

*Re: Fuel Trim Information (27psiBoom)*

I have checked my fuel trims and they are 0% all the time. And I have a brand new MAF where do I need to start looking?


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## [email protected] (Jun 5, 2002)

*Re: Fuel Trim Information (SMOOTH)*

Are you reading these with VAG-COM or with some other scan tool?


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information ([email protected])*

did you clear DTCs before logging block 032?


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (27psiBoom)*


_Quote, originally posted by *27psiBoom* »_did you clear DTCs before logging block 032?

Sounds like it.
Gary


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information (VgRt6)*


_Quote, originally posted by *VgRt6* »_
Sounds like it.
Gary

if it was done, then there you go


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## [email protected] (Oct 24, 2002)

*Re: Fuel Trim Information (27psiBoom)*

I am using ProDiag. I cleared the DTC's two days ago. I figured by now it would have readjusted. I will continue to watch it and post my findings.


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## [email protected] (Oct 24, 2002)

*Re: Fuel Trim Information (SMOOTH)*

New numbers
-0.5% and 11.5%
Brand new MAF
Suggestions?


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (SMOOTH)*

11.5% multiplicative sounds like an air leak somewhere between the MAF and pre-cat O2 sensor.
Gary


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information (VgRt6)*

an air leak should give you negative mult fuel trim numbers, higher positive numbers could mean clogged injectors, low fuel pressure, bad pump, too much air flow


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (27psiBoom)*


_Quote, originally posted by *27psiBoom* »_an air leak should give you negative mult fuel trim numbers, higher positive numbers could mean clogged injectors, low fuel pressure, bad pump, too much air flow 

An air leak will cause a lean condition, which will be taken care of using a positive fuel trim, not a negative trim. The trim is positive because the injection time is being increased to account for the excess air.
Gary


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## mrpat (Dec 13, 2005)

*Re: Fuel Trim Information ([email protected])*

So VW doesnt use adaptive memory cells to trim fuel? Such as a cell for idle, one for any given rpm range, one for decel etc etc. If you are familiar with Chrysler, they use such a system. It allows the ecm to maintain that lambda over many driving conditions. Also where does one read long term vs short term fuel trim?


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information (VgRt6)*


_Quote, originally posted by *VgRt6* »_
An air leak will cause a lean condition, which will be taken care of using a positive fuel trim, not a negative trim. The trim is positive because the injection time is being increased to account for the excess air.
Gary

mmmm not sure about it, any air leak between turbo and manifold will cause a rich condition because the injectors will still provide the same or a bit less amount of fuel according to what it written on the software and from maf/lambda/load values however the amount of air will be smaller causing and lean condition and forcing the ECU to decrease injection period to match ideal AFR, now if you get a post turbo exhaust leak then you will get a rich condition as well because it will suck air into the exhaust path till the O2 sensor, it'll detect a lean condition and increase injection period by positive fuel trims.
Please correct me if I'm wrong, but by just reading fuel trims helped me to find several boost leaks.


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (27psiBoom)*

I think we're talking about a leak in two different ways. I'm talking about a leak where unmetered air enters the engine. That would cause a lean condition. It sounds like you're talking about a leak where metered air doesn't make it into the engine (i.e., a boost leak). That would cause a rich condition.
This raises a good point about leaks in FI v. NA cars. Air leaks in a NA car cause lean conditions. Air leaks in a FI car can cause both rich and lean conditons, depending on the location of the leak in the circuit.
Gary


_Modified by VgRt6 at 11:11 AM 12-15-2005_


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## [email protected] (Jun 5, 2002)

*Re: Fuel Trim Information (VgRt6)*

My experience with air leaks on forced induction cars is that vacuum leaks cause bigger problems than boost leaks. Here's why. When you are boosting, you may be flowing 175+ g/s of air into the engine. If a few g/s leave to the atmosphere, it has an effect but not a big one since the ratio of measured air to actual air isn't far off from 100%. If you had a boost leak that blew off 20, 50, etc g/s, you'd know and hear it since the hole would be huge. Conversely, with vacuum leaks, you're talking about 5 g/s or less at idle. If you have a vacuum leak where the engine is taking in another 2 or 3 g/s, that has a huge effect, and makes the idle go nuts, since the unmetered air is a huge percentage of the total.
Anyway, for SMOOTH, I'd recommend doing the airflow test described in the first post in this thread.


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information ([email protected])*


_Quote, originally posted by *[email protected]* »_My experience with air leaks on forced induction cars is that vacuum leaks cause bigger problems than boost leaks. Here's why. When you are boosting, you may be flowing 175+ g/s of air into the engine. If a few g/s leave to the atmosphere, it has an effect but not a big one since the ratio of measured air to actual air isn't far off from 100%. If you had a boost leak that blew off 20, 50, etc g/s, you'd know and hear it since the hole would be huge. Conversely, with vacuum leaks, you're talking about 5 g/s or less at idle. If you have a vacuum leak where the engine is taking in another 2 or 3 g/s, that has a huge effect, and makes the idle go nuts, since the unmetered air is a huge percentage of the total.

Very true. This would be noticeable in the additive trim though. http://****************.com/smile/emthup.gif 
Gary


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## 27psiBoom (Jun 13, 2003)

*Re: Fuel Trim Information ([email protected])*

this is a great post http://****************.com/smile/emthup.gif 
exhaust leaks have a big influence in fuel trims as well, right now my turbo is hanging out of the manifold, damn lock nuts







, and my mult fuel trims went down -10% negative, too much fuel for the small boost I'm getting.


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## Blitzkrieg Tuners (May 8, 2003)

*Re: Fuel Trim Information ([email protected])*


_Quote, originally posted by *[email protected]* »_My experience with air leaks on forced induction cars is that vacuum leaks cause bigger problems than boost leaks. Here's why. When you are boosting, you may be flowing 175+ g/s of air into the engine. If a few g/s leave to the atmosphere, it has an effect but not a big one since the ratio of measured air to actual air isn't far off from 100%. If you had a boost leak that blew off 20, 50, etc g/s, you'd know and hear it since the hole would be huge. Conversely, with vacuum leaks, you're talking about 5 g/s or less at idle. If you have a vacuum leak where the engine is taking in another 2 or 3 g/s, that has a huge effect, and makes the idle go nuts, since the unmetered air is a huge percentage of the total.
Anyway, for SMOOTH, I'd recommend doing the airflow test described in the first post in this thread.

Bringing this old thread back to life...
Great information Andy!!! What is the best way to check for a vacuum leak. I have heard of the smoke method or using a starting fluid spray. Is anyone able to provide additional information on one of these procedures?
Thanks


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## Illegal Gardener (Oct 8, 2004)

yes, this thread is a wealth of knowledge.... it's been in my watch topics for god knows how long.
i'd suggest finding one of the foggers rather than using sprays... the sprays make a mess and can help mess up pulley lubrication, and i've heard they can deteriorate certain motor mounts. not the end of the world if you used one, but i'd suggest using somethign else.


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## Blitzkrieg Tuners (May 8, 2003)

*Re: (Illegal Gardener)*

Yeah, I just looked up one of the smoke machines... The ones I saw were about a grand.
I just swapped out the MAF with another that I had and the car is pulling in High RPMs now. I guess that I will just wait and see how she acts, because I would prefer not to make a mess in the engine bay.


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## bobmcc (Jan 3, 2005)

*I'm confused - MIL 1136*

I have DTC 1136 with block 32 at 10%. -23.4%. Why is the ADD tripping at 10%, while the MULT was simply pending at -23%. 
We had the mass airflow sensor replaced in April; no MIL then but the performance was abysmal - power dropping out on the highway etc. When the MAS was replaced the performance returned to normal - for a while. Since then I have gotten this MIL a couple of times; it stays on until cleared and along with the MIL we get poor WOT acceleration. This is the first time I've used the VAGCOM, previous mesurements were std OBDII so I don't have the ADD/MULT breakout, just that the long term fuel trim was quite negative. 
Anyhow, when the MIL is cleared and the trims are reset, the WOT acceleration is normal. Mass airflow goes to approx 110 g/s during the accelaration test outlined in the first post of this thread. 
I apologize that this post is a variation on one in the b5 forum - I started there w/o a VAG-COM to use.
Thanks,
Bob


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## Illegal Gardener (Oct 8, 2004)

*Re: (Blitzkrieg Tuners)*


_Quote, originally posted by *Blitzkrieg Tuners* »_Yeah, I just looked up one of the smoke machines... The ones I saw were about a grand.
I just swapped out the MAF with another that I had and the car is pulling in High RPMs now. I guess that I will just wait and see how she acts, because I would prefer not to make a mess in the engine bay.
you don't need a smoke machine - i know for a fact that they make cans of non-toxic non harmful to your motor gases. first thing that comes to mind, as i honestly remember hearing about it, is if you look for a supplier for fire alarm equipment, they have cans of smoke that they use during fire alarm tests... that might work.


----------



## AlbGuy40 (Jun 23, 2005)

Hi guys, I got a CEL in my GTI which I just bought and took it to my VW mechanic and he got a P1128 code. At first he thought it was most likely a bad MAF, but after looking around he found that the Overrun Cutoff Valve was not holding pressure using a hand pressure tool...







, and he said that he was going to change a lot of loose hoses that I had. All this will cost me 200 bucks, so I was wondering if i will end up paying 200 bucks for this, just to find out that I will also need a new MAF. I do NOT have any drivability problems, the car has a GIAC chip and pulls just like it did before the CEL, also the car has a stock airbox. Any help would be apreciated.

PS: I just found out that what he is changing is the diverter valve, and the procedure explained is exactly what he did, using a hand pressure tool..... Does this really diagnose anything, especially since the Diverter Valve was not tight on the thick hose in the bottom of it.....


_Modified by AlbGuy40 at 7:38 PM 11-20-2006_


----------



## VgRt6 (Mar 8, 2002)

*Re: (AlbGuy40)*

Based on my expereince with P1128 on a MKIV, the mechanic should check the fuel trim values to determine if the MAF is bad.


----------



## NJ1.8T (Nov 4, 2005)

I checked block 032 and well the first one which is idle is reading -3.0, is this normal? Any help is appreciated.
You can check your current state of trim by using VAG-COM or equivalent to look in Group 032 in your engine measuring blocks. The first two fields will have percentages. The first field tells the fuel trim at idle (Additive). The second field tells the fuel trim at elevated engine speeds (Multiplicative). Negative values indicate that the engine is running too rich and oxygen sensor control is therefore making it more lean by reducing the amount of time that the injectors are open. Positive values indicate that the engine is running too lean and oxygen sensor control is therefore making it richer by increasing the amount of time that the injectors are open.


----------



## VgRt6 (Mar 8, 2002)

*Re: (NJ1.8T)*

-3% is the limit for a CEL. What was the value in the second field? It easier to make a diagnosis with both values than it is with just one.


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## NJ1.8T (Nov 4, 2005)

*Re: (VgRt6)*

Well, I have a 3" DP now without the after cat O2 Sensor as it wouldn't come out of my other DP so I am awaiting the delivery of that which I hope is Weds. Can I still do a run with the car to get the Second Field Reading?

_Quote, originally posted by *VgRt6* »_-3% is the limit for a CEL. What was the value in the second field? It easier to make a diagnosis with both values than it is with just one.


----------



## AlbGuy40 (Jun 23, 2005)

Hi guys, my interface just came home today, and just as I expected it was the P1128 again, so I guess the mechanic changed the DV for no reason (what an ass). When I checked group 002, the last field (g/s) never actually went above ~70. My car is chipped so I was expecting for it to hit around 170 which is what its supposed to do. While idling its between 2-4, 4 being when its really cold. Also, when I just start it when its cold, it idles very very roughly (almost 200 rpms drops). All this is leading me to believe its the MAF, but theres one thing which scares me more, when i go WOT while in neutral, i hear what appears to be backfiring/missfiring noises..... Is there a way to clean the MAF before I actually need to dump 300 bucks to get a new one. Any help would be appreciated...


----------



## VgRt6 (Mar 8, 2002)

*Re: (AlbGuy40)*

Did you make sure to do the airflow test at WOT, fully floored, not just most of the way. If the test wasn't done at true WOT, then you can max out at a much lower sirflow even if the MAF is still good.
What are the values in Block 032?


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## AlbGuy40 (Jun 23, 2005)

Ok guys, I have some updates, this is what the car was spitting out today.... 

16684 (P0300)	Random Misfire Detected
INTERMITTENT
16685 (P0301)	Cylinder 1 Misfire Detected
INTERMITTENT
16687 (P0303)	Cylinder 3 Misfire Detected
INTERMITTENT
16688 (P0304)	Cylinder 4 Misfire Detected
INTERMITTENT
17968 (P1560)---Unknown Trouble Code
16795 (P0411)	Secondary Air Injection System Incorrect Flow Detected
17536 (P1128)	Long Term Fuel Trim Mul. System too Lean (Bank 1).
I ran 032, and I got -0.4 for the first field, and 23.4 for the second one.... Shouldnt they be between -10...10. I also ran group 006 and got -4.7 for the last value... I am not experiencing any severe drivability issues, especially when the car goes into limp mode, its idling perfectly, when I erase the codes, it tends to idle rough, any help would be appreciated...

I just read that the P1560 is not a problem and usually just means that Ive gonne over the redline.... so only 5 to go lol. Whats with the missfires, any particular thing that might cause them...... vaccum leak....
My cylinder 1 and 4 coils have been replaced, so I dont think its the coils either....
_Modified by AlbGuy40 at 12:40 PM 12-15-2006_


_Modified by AlbGuy40 at 12:45 PM 12-15-2006_


----------



## Space9888 (Mar 18, 2002)

*Re: Fuel Trim Information ([email protected])*

http://****************.com/smile/emthup.gif


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## VgRt6 (Mar 8, 2002)

*Re: (AlbGuy40)*


_Quote, originally posted by *AlbGuy40* »_Ok guys, I have some updates, this is what the car was spitting out today.... 

16684 (P0300)	Random Misfire Detected
INTERMITTENT
16685 (P0301)	Cylinder 1 Misfire Detected
INTERMITTENT
16687 (P0303)	Cylinder 3 Misfire Detected
INTERMITTENT
16688 (P0304)	Cylinder 4 Misfire Detected
INTERMITTENT
17968 (P1560)---Unknown Trouble Code
16795 (P0411)	Secondary Air Injection System Incorrect Flow Detected
17536 (P1128)	Long Term Fuel Trim Mul. System too Lean (Bank 1).
I ran 032, and I got -0.4 for the first field, and 23.4 for the second one.... Shouldnt they be between -10...10. I also ran group 006 and got -4.7 for the last value... I am not experiencing any severe drivability issues, especially when the car goes into limp mode, its idling perfectly, when I erase the codes, it tends to idle rough, any help would be appreciated...

I just read that the P1560 is not a problem and usually just means that Ive gonne over the redline.... so only 5 to go lol. Whats with the missfires, any particular thing that might cause them...... vaccum leak....
My cylinder 1 and 4 coils have been replaced, so I dont think its the coils either....
_Modified by AlbGuy40 at 12:40 PM 12-15-2006_

_Modified by AlbGuy40 at 12:45 PM 12-15-2006_

I would start by replacing the MAF. Those trims in 032 are WAY out o wack. A multiplicative value that high on a MKIV usually indicates that the MAFis dying or dead.


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## AlbGuy40 (Jun 23, 2005)

Took the MAF out today, used electrical contact cleaner, put it back in, its still idling like crap, however the MAF actually looked pretty clean, WAY cleaner then my old MK3 Golfs. I forgot which block i checked, but its the one where the values are both suppsed to be 111, my first value was 111, but my second one was intermittent, it was going from 0-100, kinda like it had a loose connection somewhere. I think this was supposed to test the O2 sensor.....
BTW, has anyone ever used Seafoam on a 1.8T, since the previous owner basically didnt drive the car for almost 2 years......., and a Seafoam treatment might help things...


_Modified by AlbGuy40 at 5:14 PM 12-15-2006_


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## VgRt6 (Mar 8, 2002)

*Re: (AlbGuy40)*

That's Block 030. The first set is for the pre-cat O2 sensor, which is the one that deals with the trims. Your O2 sensor is likely fine.
You need a new MAF, trust me.







They may look clean, but they still go bad.


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## AlbGuy40 (Jun 23, 2005)

*Re: (VgRt6)*

New update guys, I got a MAF today installed it, and what do you know, car starts up perfectly (it didnt start at 5 in the morning when i was going to work, so i had to take moms car







). Idle is very good at exactly 760 rpm, and Group 002 is going up to 140














. However, because I just reset the Check Engine light, I havent gotten any updated 032 values. The only thing im kinda worried about is that it feels like its holding back on boost, or it might just be me, because usually i would get the ASR light coming on all the time i go WOT in second gear. Ill let the ECU adapt i guess for a while.... another question, is there a particular block to check Boost pressure, or do I need a seperate boost gauge.....


----------



## VgRt6 (Mar 8, 2002)

*Re: (AlbGuy40)*

I can't help much with the boost, but there is a block that will tell you the requested boost along side the actual boost. It might be 115 or 120. Check in the 1.8t forum.
Go and drive on a highway or faster secondary road for 5 minutes. The fuel trims will quickly update.


----------



## Space9888 (Mar 18, 2002)

*Re: (VgRt6)*

my car did something similar when i had exhaust leak before first 02 sensor and cats, (my exhaust manifold had a hairline crack about 2" long right between cyl#3 and #4) car would stumble at idle tho (ecu thought i was running lean since there was no vaccum leaks on the intake side. i was relacing all kinds of parts (map sensor), maf sensor, 02s







the wierdest thing was you couldnt hear it at all. at the time i didnt have any diag equiptment, my revo tunner found what it was. and after replacing the manifold and clearing faults problems went away.


----------



## AlbGuy40 (Jun 23, 2005)

Ok guys, I have some bad updates, I dont know what the hell is going on. Last night right when I started the car when it was cold, it surged for a bit and my ASR light came on (no flashing). I turned the car and turn it back on and it was running perfect after, no ASR light, and I also noticed that I had gotten out of the soft limp mode since the car was ripping in second and third and barely had traction...
This is what I got after I scanned the car, remember, I HAD NO CEL...
17965 (P1557)---Unknown Trouble Code (I later found that this is the same as P1557)
17705 (P1297)---Unknown Trouble Code (P1297????? i think...)
16486 (P0102)	Mass or Volume air Flow Circuit Low Input (WTF.... I just got a new one yesterday)
INTERMITTENT
16795 (P0411)	Secondary Air Injection System Incorrect Flow Detected (This **** has been on for a longgggggggggggg time, can someone PLEASE tell me how to remove the SAI pump, because I have a feeling that ALL these codes come as a result of the SAI)
I cleared these codes and then drove for a while (about 70 km). Today, this is what I get.......
17545 - Fuel Trim: Bank 1 (Add): System too Rich
P1137 - 35-00 - -

What I DONT understand is how my car went from being too lean (P1128) to being rich now???? I checked Group 032 and my trims are -9.0, and 7.0 on the second one. Group 002 tests show that my MAF is WORKING like its supposed to since I hit 150 g/s.... Any ideas about what is going on.... can a failing SAI pump cause these codes (i know P0411 is usually caused by a failing SAI). Also, how can I do an accurate vaccum and boost leak test....

Can the fact that the car has not been driven for more then 1 year have anything to do with these codes, after I changed my MAF, the car started perfectly, so i thought that that was it, now i dont know what to do......


_Modified by AlbGuy40 at 9:36 PM 12-17-2006_


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## VgRt6 (Mar 8, 2002)

*Re: (AlbGuy40)*

Are you sure you are using the correct MAF for your car?


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## AlbGuy40 (Jun 23, 2005)

Ye matching part numbers, i got it at a known OEM VW Parts place. I jsut went out to get some gas today, and the first few minues of driving were good, but then I could feel that I had gonne into the soft limp mode again.


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## VgRt6 (Mar 8, 2002)

*Re: (AlbGuy40)*

Very strange. I'll have to give this some more thought.


----------



## GTIRACER2.0t (Aug 23, 2000)

*Re: (VgRt6)*

im waking this thread up







Bump


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## mesuky22 (Feb 20, 2003)

*Re: (Space9888)*


_Quote, originally posted by *Space9888* »_my car did something similar when i had exhaust leak before first 02 sensor and cats, (my exhaust manifold had a hairline crack about 2" long right between cyl#3 and #4) car would stumble at idle tho (ecu thought i was running lean since there was no vaccum leaks on the intake side. i was relacing all kinds of parts (map sensor), maf sensor, 02s







the wierdest thing was you couldnt hear it at all. at the time i didnt have any diag equiptment, my revo tunner found what it was. and after replacing the manifold and clearing faults problems went away. 

i wonder if this is my problem i have a stumbling idle and replaced everything, plus my fuel trim values are way out of specs, ill check them tonite and post them and see if someone can help.


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## SB_Beetle (Oct 11, 2003)

So '032 readings of -.8 and -.8 are good to go?
Is it normal for these values to remain constant?


_Modified by SB_Beetle at 2:02 PM 6-29-2007_


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## VgRt6 (Mar 8, 2002)

*Re: (SB_Beetle)*

Those values are well within the allowed values.
They won't fluctuate quickly, but if you watch them while you drive, you might see the second one change slightly every few miles.


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## SB_Beetle (Oct 11, 2003)

Thanks VgRt6!


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## SB_Beetle (Oct 11, 2003)

Would readings of 0 and -1.6 be WNL?


_Modified by SB_Beetle at 2:42 PM 7-1-2007_


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## VgRt6 (Mar 8, 2002)

*Re: (SB_Beetle)*

The acceptable limits are +/- 3% for Field 1 (additive trim) and +/- 10% for Field 2 (multiplicative trim).


----------



## CL1.8T (Dec 14, 2007)

*Re: Fuel Trim Information ([email protected])*

I know I'm a few years behind, but I have been having trouble with my 2001 1.8T, and my mechanics have ran out of things to do while my MIL would come on about every 200km. It seems to be complaining about the Fuel Trim. Right now, the LongTerm Fuel Trim (Bank 1) is at 1% and (Bank3) is at 10%. I can just sense the MIL will be lighting up soon...and every time I will be driving on the highway when it lit up. What data should I be looking for exactly to determine the cause? (Sorry, I'm using a OBD-II reader that is giving me different name to that what you are suggesting)
Thank you.


----------



## [email protected] (Jun 5, 2002)

*Re: Fuel Trim Information (CL1.8T)*

What you posted makes no sense. A 1.8T only has one cylinder bank. You cannot check the stuff in this thread with a generic scanner. Scan with VAG-COM or the factory tools then post your results.


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## enigmatic (Jan 28, 2008)

I have a 2002 VW Bora... I'm noticing a full tank of my gas is only lasting for like one week. I wuld only get like 210km on the full tank.
When I use VAG I get:
17851 - Potentiometer for EGR (G212): Signal too Low
P1443 - 35-00 - -
17811 - EGR System: Regulation Deviation
P1403 - 35-00 - -
16555 - Fuel Trim; Bank 1: System Too Lean
P0171 - 35-10 - - - Intermittent
16555 - Fuel Trim; Bank 1: System Too Lean
P0171 - 35-10 - - - Intermittent
I've used VAG-COM and looked at Group 032, when the car is idle
10.2	-2
10.2	-2
10.2	-2
0.8	-2
3.1	-2
0	-2
0	-2
0	-2
When it's idle i get 10.2.. .but while driving i notic it reaches zero. Withthe 10.2 do i need a new MAF? Could it be vacuum hoses or the maf? I really am car novice but i'm trying my best here










_Modified by enigmatic at 5:27 AM 2-4-2008_


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## 2002gtibluvr6 (Oct 5, 2002)

*Re: Fuel Trim Information ([email protected])*

alright ill give it a shot, ive had consistant codes for the last year or so. ive changed and cleaned MAF as well as trying both 2.0 maf and 24v maf car is a stage 2 supercharged 24v.
i keep getting codes about long term fuel trim too rich but ill also get long term fuel trim too lean...both addative, both intermittent. i also get MAF implausible signal, also intermittent
i just checked my block 032 and say first field -4.5% and second field -10% codes have been persistent since stage 2 installed...sometimes they will go away and stay away for a couple weeks then come back. im at high altitude and the program was writen at sealevel, and it has a larger MAF housing then stock, and uses different fuel pump, injectors and FPR. so you think the problem may be with the sensor itself, possibly wiring coming loose *ie losing contact from vibration and not sending proper data?* or is it something simple like the program expecting a certain level of air *ie sealevel* and not getting it *high altitude...also run aobut 2lbs low on boost from alitude* do you think a slight tweak with lemmiwinks could fix my problem? car runs good, but when i clear the codes it runs lumpy for a while then smoothes out. 
im really tempted to try lemmiwinks and slightly tweeking fuel trims with that since they seem really close to what is acceptable *could be the cause of my CEL"s turning on and off* or do you guys think there is a underlying problem either thata im not guessing or one of the situations i gave above. hopefuly someone can help


----------



## alexr44 (Dec 12, 2003)

*Re: Fuel Trim Information ([email protected])*

Fantastic info - love the vortex. However....
Is there any way to test the MAF ? At a minumum of $190, I don't want to just buy one, and see what it does.
My trims are: -2.3% and sadly... 25% so according to what I've read, I need a MAF. But being an electrical component they are non-returnable... and $190 right now is not something I want to waste.
The old MKII's could be resistance tested across the range.... do these have any options like this?
-Alex.


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (alexr44)*


_Quote, originally posted by *alexr44* »_Fantastic info - love the vortex. However....
Is there any way to test the MAF ? At a minumum of $190, I don't want to just buy one, and see what it does.
My trims are: -2.3% and sadly... 25% so according to what I've read, I need a MAF. But being an electrical component they are non-returnable... and $190 right now is not something I want to waste.
The old MKII's could be resistance tested across the range.... do these have any options like this?
-Alex.

Is this on a MKIV? If it is, then you DO need a MAF. No question about it. I've seen it doesns of times where the multiplicative trim was 25% or close to it and EVERY single time it's been the MAF.
Also, you can often get a MAF for a lot less than $190. What's the year, model and engine of your car?


----------



## [email protected] (Jun 5, 2002)

*Re: Fuel Trim Information (alexr44)*


_Quote, originally posted by *alexr44* »_Fantastic info - love the vortex. However....
Is there any way to test the MAF ? 

Read this:
http://wiki.ross-tech.com/index.php/Fuel_Trim_Info


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## alexr44 (Dec 12, 2003)

*Re: Fuel Trim Information ([email protected])*

Does that redline test have to be done in a gear? It can't just be done in a garage in nuetral?

And it's an '03 20th anniversary (1.8t)
The cheapest NEW bosch MAF I could find was $165 before shipping.


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## [email protected] (Jun 5, 2002)

*Re: Fuel Trim Information (alexr44)*


_Quote, originally posted by *alexr44* »_Does that redline test have to be done in a gear?

Yes, the vehicle needs to be under full load.

_Quote, originally posted by *alexr44* »_It can't just be done in a garage in nuetral?

No, the vehicle needs to be under full load.


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## alexr44 (Dec 12, 2003)

*Re: Fuel Trim Information ([email protected])*

Ok, good to know.
Hopefully later today I will get a chance to do that.
Should the codes be cleared before I do that. Do they have to remain there. Or does it make a difference either way?
I think someone said the codes cause the car to enter "limp" mode... would that effect the number I'm logging?


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (alexr44)*

It doesn't matter if the codes are in memory or not. They're a historical record, not something that determines how the car runs. If the ECU deems that the car should be run in limp mode or non-limp mode, then it will regardless of what's in memory.


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## alexr44 (Dec 12, 2003)

*Re: Fuel Trim Information (VgRt6)*

Well, I replaced the MAF and gave it a few days. No lights on yet.. That must have been it.
-Thanks for the help and good info.


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (alexr44)*


_Quote, originally posted by *alexr44* »_Well, I replaced the MAF and gave it a few days. No lights on yet.. That must have been it.
-Thanks for the help and good info.

Problem solved! http://****************.com/smile/emthup.gif


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## morpheusx (May 5, 2008)

Ok this has got me stumped, I am working on my wife's 2001 1.8t Beetle, I am getting a lean code, the 02 sensor is new, and the MAF is maybe a year old at most, I can't seem to find any vacuum leaks either.
My fuel trim is 6.6 and -14.6
The car seems to be running good but seems to lately take long shifts. Any suggestions.
1 Fault Found:
17544 - Fuel Trim: Bank 1 (Add): System too Lean 
P1136 - 35-00 - -
Readiness: 0000 1101


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## morpheusx (May 5, 2008)

I forgot to ask is it possible that it can be cause from clogged fuel injectors.


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## VgRt6 (Mar 8, 2002)

*Re: (morpheusx)*


_Quote, originally posted by *morpheusx* »_Ok this has got me stumped, I am working on my wife's 2001 1.8t Beetle, I am getting a lean code, the 02 sensor is new, and the MAF is maybe a year old at most, I can't seem to find any vacuum leaks either.
My fuel trim is 6.6 and -14.6
The car seems to be running good but seems to lately take long shifts. Any suggestions.
1 Fault Found:
17544 - Fuel Trim: Bank 1 (Add): System too Lean 
P1136 - 35-00 - -
Readiness: 0000 1101


Your trims are very interesting and don't make much sense. They indicate that the engine is running 6.6% lean at idle and 14.6% rich at increased engine speeds. The only reasonable things that I know that cause the simultaneous very lean and very rich trims is a bad MAF or an incorrect MAF. If the trims were normal after the MAF was replaced and are bad now, then my guess is that the newish MAF is bad.


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## morpheusx (May 5, 2008)

I think I found the leak. The plastic hose out of the side of the engine underneath the intake manifold was cracked in two. I'm going to try to put it back together using a radiator hose and two clamps. Hopefully that is what was causing it. I'll report back.


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## VgRt6 (Mar 8, 2002)

*Re: (morpheusx)*

I still think it's the MAF. How would a air leak cause a major rich condition at elevated engine speeds?


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## morpheusx (May 5, 2008)

I think you are right, I fixed the pipe and the numbers didn't change but by a few percents. I am leaning more towards its being the MAF as well. I went in my garage and grabbed my Old MAF and cleaned it out real good and left it dry overnight and put it in this morning. The Trim numbers are looking much better now, I put 2 10 mile runs on it and they look like they are starting to hold at 4.3 and 5.5 (although the second one raised from 3.9 on the second run) Should I go ahead and clear the code now.


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## VgRt6 (Mar 8, 2002)

*Re: (morpheusx)*

Those recent trims are MUCH better. Go ahead and clear the code unless you need it to get free warranty service. If it's out of warranty, then clear and see if it comes back. Hopefully it won't.


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## morpheusx (May 5, 2008)

Been driving all day today in the Lime green Easter egg. I put about 100 miles on it today with about 7 or 8 driving cycles, all seems good. Right now it looks like I was able to resurrect the OLD MAF that was laying in the garage. I didn't know you clean them when I originally replaced it. I am not sure how much of an effect the Vac leak had with my situation. But the latest trim info I have is 4.7 and 3.9 and the car even though it felt like it was driving good before feels like a different car. Thanks for your help and time I am so glad I bought the VAG COM this week, should have bought it two years ago when we bought the Beetle, it has already become one of the most valuable tools in my garage.


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## VgRt6 (Mar 8, 2002)

*Re: (morpheusx)*

http://****************.com/smile/emthup.gif


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## dkveuro (Jul 23, 2002)

*Re: Fuel Trim Information (Lotust)*

Hello,
I just ran the vag com because i keep getting the "1 DTC's Found:
17536 - Fuel Trim: Bank 1 (Mult): System too Lean
35-00 - -" code

the first Lambda value was -8.6

the second Lambda value was 24.2

I read this thread but i dont understand it fully. can anyone help me. I can send you the logs i took. 
====================================================
I would run a fuel pressure test.
A weak pump will ramp up the STFT very quickly and LTFT can be over 19%.
Plugs/etc will not change it. I have done a few with bad pumps lately..last one was a 2004 2.0 n/a Beetle.


_Modified by dkveuro at 10:22 PM 10-6-2008_ 

_Modified by dkveuro at 10:23 PM 10-6-2008_


_Modified by dkveuro at 10:24 PM 10-6-2008_


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## FaelinGL (Nov 28, 2004)

*Re: Fuel Trim Information (dkveuro)*


_Quote, originally posted by *dkveuro* »_Hello,
I just ran the vag com because i keep getting the "1 DTC's Found:
17536 - Fuel Trim: Bank 1 (Mult): System too Lean
35-00 - -" code
the first Lambda value was -8.6
the second Lambda value was 24.2
I read this thread but i dont understand it fully. can anyone help me. I can send you the logs i took. 


If the numbers you posted are the fuel trim numbers, then your MAF is going. Do you have a MKIV?
Mike


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## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (FaelinGL)*

I agree. Those are classic trims for a bad MKIV MAF.


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## FaelinGL (Nov 28, 2004)

*Re: Fuel Trim Information (VgRt6)*

Up for watched.
Mike


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## rovi (May 21, 2008)

hello,
i have a big problem and i don't now how to fix it.i read yesterday this topic and it's exacly the problem that i have.
made a test today with the VAG-COM and have this fault:
16556 - Fuel Trim: System Too Rich: Bank 1
P0172 - 35-10 - - - Intermittent
i made a test at the pos o32 and the values are:
first line: -13,3%
second line: -0,8%
please somebody help.i don't now what to do enymore.there are 2 years since i have this fault.thank you


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## VgRt6 (Mar 8, 2002)

*Re: (rovi)*

Your car is running very rich at idle, but not at elevated engine speeds. It could be from leaking injectors or a bad MAF sensor (or something else). I would start with the MAF sensor.


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## rovi (May 21, 2008)

*Re: (VgRt6)*

the thing is that i unpluged the MAF today to see how it runs.with the MAF pluged in there are some noises in the exhaust.on idle when i press the gas pedal you can hear something like "puf puf"(don't now how to call them







).without the MAF pluged in can't hear that anymore.i will try to clean the MAF.if it works same think have to change it.thx for the answer.i'll let you now what's happening.maybe i'll still need your help.thx again


----------



## VgRt6 (Mar 8, 2002)

*Re: (rovi)*

Cleaning doesn't usually work on the recent thin film MAFs. It mostly works on the older hot wire MAFs. It won't hurt to try and clean it, but most likely you'll need to buy a new one.


----------



## rovi (May 21, 2008)

*Re: (VgRt6)*

yeap...i cleaned it today but it's same thing.have to change it







bosch it's very expensive.do you now anything else that is cheaper and good?thanks alot


----------



## VgRt6 (Mar 8, 2002)

*Re: (rovi)*

What's the part number on your MAF? Is it 06A906461A?


----------



## rovi (May 21, 2008)

*Re: (VgRt6)*

VW GOLF IV (1J1)
2.0
KW/PS: 85/115
Baujahr: 08.98-05.04
Motorcode AQY,APK
OEM-Nummer (Originalnummern) dienen nur zum Vergleich:
0280218002
06A906461A
yes that's the one.i've just checked on a website










_Modified by rovi at 11:22 AM 12-10-2008_


----------



## rovi (May 21, 2008)

hi again,
i've changed the MAF but sometimes at cold start the car doesn't work well.when it's warm i don't get those noises in the exhaust anymore.i've put the car again on the vag-com and at pos 032 i get this:
1st line: -18%
2nd line -14,8%
with thw new MAF i get this fault codes:
17535 - Fuel Trim: Bank 1 (Mult): System too Rich
P1127 - 35-10 - - - Intermittent
16556 - Fuel Trim: System Too Rich: Bank 1
P0172 - 35-00 - -
pls help me with this.what should i check at next?what could in be?
thanks


_Modified by rovi at 10:47 AM 12-14-2008_


----------



## VgRt6 (Mar 8, 2002)

*Re: (rovi)*

Are those the fuel trims with the new MAF? Clear codes (even if there aren't any) to reset the trims to 0. Drive for a while and check again.
Do you know what engine code you have? Is your engine an AEG 2.0 liter?


----------



## rovi (May 21, 2008)

*Re: (VgRt6)*

yes...the codes are with the new MAF.it's not a Bosch.i buyed something cheaper made in germany.i will drive with this MAF for a couple of days.to see how it works.
the engine code is AQY...the one with lots of problems.i will post next week how it works.thx VgRt6


----------



## VgRt6 (Mar 8, 2002)

*Re: (rovi)*

That MAF may not be valid for the AQY engine. It is for the AEG engine, but I'm not sure about any others. The fuel trims that you now have are similar to those on non-AEG 2.0 MKIVs using the 06A906461A MAF. My guess is that it isn't the correct MAF for your car.
Is there a dealer that you can call and ask what the correct MAF part number is for your car?


----------



## rovi (May 21, 2008)

*Re: (VgRt6)*

yes i can check.the thing is that it is the same part no. like the original Bosch from car.i will call tomorrow to see if it's the right one


----------



## rovi (May 21, 2008)

hi VgRt6,
i checked today the FPR and i don't now if it's working properly.how can i check it?it took of the vaccum hose to see if is any difference.the only difference is that the car comes down lo idle mode very slowly from 1000rpm to 800rpm.how should the car work without the FPR?at the position 033 at vag com i get this value: -25% (at first line) what should i check as next?thank you


----------



## VgRt6 (Mar 8, 2002)

*Re: (rovi)*

I'm not sure how to check the FPR. They're pretty cheap, so you could possibly just replace it. I wouldn't run it too long with the vac line off (so that the FPR is not inactive and there isn't a large vacuum leak).


----------



## rovi (May 21, 2008)

*Re: (VgRt6)*

ok.i will try to replace it.thank you


----------



## Justinf (Oct 1, 2008)

I have a 180hp 1.8t Mk IV Jetta
I have been having crazy fuel consumption for a while, also the car jerks as it boosts but otherwise feels fine, although I have felt it become lazy and a quick test againts a friends audi 1.8t and I'm sitting with him instead of pulling away...
I got a cable and I'm running shareware vag com (which I would love to buy but cant afford right now) and did data logging using vwtool.
I got the following error in VAG com
1 Fault Found:
17544 - Fuel Trim: Bank 1 (Add): System too Lean
P1136 - 35-10 - - - Intermittent
Readiness: 0000 0000

Stupidly I reset it all before I read this forum so I have to do some driving tomorrow to get some data.....
One thing I did try is the AFM check, I ran to red line in 2nd and all I got was 126.7 instead of 144????? Anything to worry about?
I have done a quick inspection for pipe leaks but will have to do a thorough one when the car is cold and I will post data later... I did have a perished pipe on the breather to the top of the engine / air intake pipe, so I'm suspecting a dirty AFM....

Any ideas? Any help is appreciated!!!


----------



## esilviu (Nov 1, 2006)

Hello,
Could anybody please tell me which block of vagcom should I check in order to see if ECU is in closed loop or open loop?
Thanks


----------



## VgRt6 (Mar 8, 2002)

*Re: (esilviu)*

Not sure about a measuring block, but you can use the OBDII section of the VAG-COM software to tell you.


----------



## esilviu (Nov 1, 2006)

Could you post a link to OBDII section of the VAG-COM software, because I don't find it
Thanks


----------



## VgRt6 (Mar 8, 2002)

*Re: (esilviu)*

On the opening screen, the bottom left button should say OBD or OBDII. It's in there.
Edit: Here you go - http://www.ross-tech.com/vcds/....html. It should be in one of the "Read Data" drop-downs.


_Modified by VgRt6 at 12:27 PM 2-6-2009_


----------



## esilviu (Nov 1, 2006)

Tank you very much


----------



## rumpinho~ (Sep 18, 2008)

*Re: (esilviu)*

I went into the measuring blocks under "Engine-01" and punched in block 032 and clicked on Go. the 4 fields have N/A in them, not a single number.
I this the correct way to do this. I have a serial key-com cable. Also when I click on readiness it gives me an error stating that maybe the car is not OBD-II compatible. 
the car is a 00 AGU engine.
Where can I check the fuel trims?


----------



## vr6jettagli (Mar 30, 2008)

anyone ever had code 17573
P1165
Bank1, Long Term Fuel Trim, Range 1 Rich Limit Exceeded , and maybe know what the problem is? 
I know alldata says to check fuel pressure regulator but i know its brand new. what else could it be thanks guys


_Modified by vr6jettagli at 6:42 PM 4-10-2009_


----------



## jmf (Apr 17, 2007)

Hi guys.
I also get the "17536 - Fuel Trim: Bank 1 (Mult): System too Lean" code along with high 032.2 values.
Problem is that last weekend I changed the MAF (the old one was shot, 70g/s 3rd gear WOT log) with a brand new one. The car now runs fine, MAF reading is up to 165g/s, but I'm getting the code again, along with 22.7% multiplicative trim. The additive trim is 0.9% (or -0.9 don't remember).
Today I checked for leaks but couldn't fine none. Instead I found that one of the downpipe screws was loose and I tightened it. This solved a problem I had since buying the car 6 months ago, where it would hiccup on acceleration and literally sound like losing boost (i guess the shaky downpipe was the cause).
Still, tightening the screw didn't solve the trims problem. I cleared the code, drove for 20km and the trim is back at 20%. No code yet, but I feel it's coming








Any other ideas what I could check?
ps: 1.8t with k04 and remap. Could this have anything to do with it?


----------



## jmf (Apr 17, 2007)

Ok, code is back. Any ideas anyone?


----------



## goosler (Feb 11, 2002)

*Re: Fuel Trim Information (VgRt6)*

bump


----------



## dkfackler (Feb 8, 2010)

*Re: Fuel Trim Information ([email protected])*

So if I get 112-115 g/sec on a 115hp 2.0 liter normally-aspirated, is the MAF dodgy? That seems to be way too much air( expected value is ~92g/sec). It seemed implausible, so I ran the test several times.
That's what I'm seeing, along with a -18 multiplicative fuel trim.
To my thinking, too much perceived air = too much real fuel, therefore the rich multiplicative.

Thoughts?
d


_Modified by dkfackler at 12:27 PM 2-18-2010_


----------



## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (dkfackler)*

You multiplicative fuel trim is -18%? That sounds like a bad MAF to me.
What is the additive trim?


----------



## dkfackler (Feb 8, 2010)

*Re: Fuel Trim Information (VgRt6)*

Yeah, I'm thinking MAF, too, but wanted other opinions.
Additive trim bounces between -2.x and +3.2 or so.
Odd that the MAF is reading high. I wonder whether this is truly the right unit for the car. It was a rebuild, purchased maybe 3 years ago. Perhaps a case of 'right housing but wrong internals'
What started all this was a P0351 and P0352 code that appear to be fraudulent. These are ignition coil codes, but there are no ignition-related drivability issues, and 3 coil swaps later, the codes persist. NO misfires are logged-- none. The local VW guys couldn't figure it out either.
In pondering all of the above, I wonder whether the rich F/A ratio is fooling the ECU into the ignition coil mis-diagnosis, or causing a miss that is so sporadic as to be ignored by the ECU.
I've just sent my old Key-Com in to be swapped for the Hex-Usb, so will have to wait for later developments.

d


----------



## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (dkfackler)*

What engine code do you have? What is the part number on the MAF?


----------



## dkfackler (Feb 8, 2010)

*Re: Fuel Trim Information (VgRt6)*

Engine code:
AZG
MAF OEM part number:
06A906461A
I called VW and learned that my engine needs the 06A906461G MAF. I have the wrong one...
This may relieve many headaches all at once.
d


----------



## VgRt6 (Mar 8, 2002)

*Re: Fuel Trim Information (dkfackler)*

I was wondering if you were using the wrong 2.0 MAF. A lot o people who needed the 'G' MAF bought the 'A' MAF by mistake, likely because it used to be ridiculously cheap (<$40). Swapping the 'A' MAF with a 'G' MAF will definitely fix your problem.


----------



## dkfackler (Feb 8, 2010)

*Re: Fuel Trim Information (VgRt6)*

I DID get the A instead-- the parts store guy told me that thery were the same-- "they're both listed for your car, buddy".
Will chase the right unit down tomorrow.
Thanks.
d


----------



## dkfackler (Feb 8, 2010)

*Re: (jmf)*

Shouldn't the 1.8T MAF reading be only ~120 g/s?
Maybe the wrong MAF? Call the VW dealer, speak to the parts dept. and ask for the MAF part number corresponding to your engine code. 
I've been chasing a similar situation.
d


----------



## Beersix (Oct 19, 2007)

Hey, i need some help.
My car is been getting some weird electrical problems lately.
First, Last summer i started getting ABS/ASR lights + Engine light, for which my mechanic suggested to replace the TB+MAF+CTS along with a new air filter, problems went away until winter time started. During winter my ABS/ASR started malfunctioning again, sometimes they will light up then they will go away. The engine light started acting up again as well. I was getting codes that described a bad MAF. I had the MAF replaced during the month of december and problem with the angine light went off but ABS/ASR remain active. 
Just last week, the cable that connects from the battery to the starter broke in half and had it replaced. Yesterday, all of the sudden my car started acting up again>> I turned it on and drove for a less than 20 feet and the car shut off its self while moving. I tried to turn it back on but i couldn't. I tried one more time and it finally started but it was running rough as if the coilpack was craked. The ABS/ASR lights went away and the car was running fine again but the engine light remained on. Today, I took the car to Autozone to get it scanned and two codes were detected....P1128 (17536) and P0304 (16668).
I did some research and everything points towars a bad MAF. This problem seem to occur every time we change temperature from winter to summer. Is it normal for MAfs to go bad for no apparent reason?? Can somebody explain to me if this is normal?? I already replaced the MAF 2 times during last year and the manufacturer might not want to replace the defective product??


----------



## jtz54 (Dec 14, 2009)

*Re: Fuel Trim Information ([email protected])*

Besides the P1128 code which I usually get while cruising down the highway, I've been getting a hesitation when the engine is cold. Doesn't go away for several miles but acts like the engine is going to die when you press on the gas pedal. Just a big lack of power when the pedal is pressed. I've already changed the MAF and the two oxygen sensors since they seem to be the main culprit for the P1128 code. When the cold problem happens no code ever gets thrown. I've checked the vacuum hose for leaks but so far have found none. Any suggestions??


----------



## 2000jett (Sep 10, 2010)

Can you change any performance settings with the Ross-Tech program?


----------



## 2000jett (Sep 10, 2010)

Check for vacume leaks or air leaks past your map sensor vw are really sensitive to vacume leaks and air intake leaks


----------



## AaronGS (Jan 4, 2011)

*17536*

hi, 
I have just spent a while reading through this fuel trim info but need a little help. 

I have a mk4 golf (engine code AUM) thats an APR Stage 3+ conversion. It should be putting out 320bhp on the current map. 
It feels under powered at times and VCDS-Lite shows the 17536 (system too lean) code and 17963 (charge pressure max limit exceeded). 
I have logged the MAF in block 002. The best I got was 162g/s at ~6200rpm in 3rd gear. 
Block 032 reports 0% in the first field and 20.3% in the second. 
My undestanding is that this is likely to be the MAF sensor at fault. I am correct? 

Many Thanks 

Aaron


----------



## AaronGS (Jan 4, 2011)

Bump - any ideas?


----------



## animaniac (May 26, 2005)

Charge pressure max limit exceeded thats overboosting. 

Check wastegate / actuator feed pipe. 

Could be faulty map sensor over reading.


----------



## Dana @ Ross-Tech (Sep 15, 2009)

AaronGS said:


> Bump - any ideas?


 If you need further assistance with this, post the complete Auto-Scan from this car and the MB 032 data.


----------



## AaronGS (Jan 4, 2011)

Dana, thanks. I will try to do that later. I ran an auto scan after measuring blocks 002 and 032. I then dropped the laptop, smashing the screen:banghead:. I should get it back today, fingers crossed. 

Cheers 
Aaron


----------



## AaronGS (Jan 4, 2011)

VCDS-Lite Version: Release 1.0 
Friday, 07 January 2011, 19:10:49:30718 


Chassis Type: 1J - VW Golf/Bora IV 
Scan: 01,02,03,08,15,16,17,19,22,29,35,36,37,39,46,47,55,56,57,75,76 

------------------------------------------------------------------------------- 
Address 01: Engine Labels: 06A-906-032-AUM.LBL 
Controller: 06A 906 032 DR 
Component: 1.8L R4/5VT G 0003 
Coding: 11500 
Shop #: WSC 01972 
2 Faults Found: 
17536 - Fuel Trim; Bank 1 (Mult): System too Lean 
P1128 - 35-10 - - - Intermittent 
17963 - Charge Pressure: Maximum Limit Exceeded 
P1555 - 35-10 - - - Intermittent 
Readiness: 0000 1001 

------------------------------------------------------------------------------- 
Address 03: ABS Brakes Labels: 1C0-907-37x-ASR.LBL 
Controller: 1C0 907 379 D 
Component: ASR FRONT MK60 0103 
Coding: 0021505 
Shop #: WSC 01317 
No fault code found. 

------------------------------------------------------------------------------- 
Address 15: Airbags Labels: 6Q0-909-605-VW5.LBL 
Controller: 6Q0 909 605 A 
Component: 27 AIRBAG VW5 01 0006 
Coding: 12855 
Shop #: WSC 01317 
1 Fault Found: 
00532 - Supply Voltage B+ 
07-10 - Signal too Low - Intermittent 

------------------------------------------------------------------------------- 
Address 17: Instruments Labels: 1J0-920-xx5-17.LBL 
Controller: 1J0 920 925 A 
Component: KOMBI+WEGFAHRS. BOO V04 
Coding: 05412 
Shop #: WSC 00000 
Ident.-Nr. WEGFAHRS.:VWZ6Z0Y2195952 
No fault code found. 

------------------------------------------------------------------------------- 
Address 19: CAN Gateway Labels: 6N0-909-901-19.LBL 
Controller: 6N0 909 901 
Component: Gateway KCAN 0001 
Coding: 00006 
Shop #: WSC 01317 
No fault code found. 

------------------------------------------------------------------------------- 
Address 46: Central Conv. Labels: 1J0-959-799.LBL 
Controller: 1J0 959 799 AH 
Component: 4U Zentral-SG Komf. 0001 
Coding: 04096 
Shop #: WSC 01317 
1 Fault Found: 
00953 - Interior Light Time limit 
25-10 - Unknown Switch Condition - Intermittent 

------------------------------------------------------------------------------- 
Address 56: Radio Labels: 1J0-035-18x-56.LBL 
Controller: 1J0 035 186 E 
Component: Radio BNO 0005 
Coding: 01403 
Shop #: WSC 01317 
No fault code found. 

End -------------------------------------------------------------------------------------------------- 

Group B:	'032 
Adaptation (Idle)	Adaptation (Partial) 
TIME	Bank 1 Sensor 1	Bank 1 Sensor 1 
STAMP	%	% 
0.53	0	18 
1.74	0	18 
3.04	0	18 
4.35	0	18 
5.66	0	18 
6.97	0	18 
8.38	0	18 
9.69	0	18 
10.89	0	18 
12.2	0	18 
13.42	0	18 
14.83	0	18 
16.12	0 18 
17.34	0	18 
18.54	0	18 
19.75	0	18 
21.05	0	18 
22.36	0	18 
23.58	0	18 
24.87	0	18 
26.19	0	18 
27.59	0	18 
28.79	0	18 
30.1	0	18 
31.32	0	18 
32.73	0	18 
34.02	0	18 
35.24	0	18 
36.44	0	18 
37.75	0	18 
39.06	0	18 
40.47	0	18 
41.67	0	18 
43.08	0	18 
44.29	0	18 
45.48	0	18 
46.71	0	18 
48.12	0	18 
49.53	0	18 
50.82	0	18 
52.04	0	18 
53.24	0	18 
54.45	0	18 
55.86	0	18 
57.36	0	18 
58.56	0	18 
59.78	0	18 
61.09	0	18 
62.39	0	18 
63.68	0	18 
64.9	0	18 
66.21	0	18 
67.62	0	18 
68.91	0	18 
70.13	0	18 
71.35	0	18 
72.66	0	18 
74.07	0	18 
75.36	0	18 
76.58	0	18 
77.78	0	18 
78.98	0	18 
80.18	0	18 
81.41	0	18 
82.7	0	18 
83.92	0	18 
85.12	0	18 
86.53	0	18 
87.74	0	18 
88.94	0	18 
90.14	0	18 
91.36	0	18 
92.77	0	18 
93.97	0	18 
95.28	0	18 
96.49	0	18 
97.9	0	18 
99.2	0	18 
100.51	0	18 
101.92	0	18 
103.13	0	18 
104.43	0	18 
105.74	0	18 
107.05	0	18 
108.56	0	18 
109.85	0	18 
111.07	0	18 
112.27	0	18 
113.47	0	18 
114.68	0	18 
115.99	0	18 
117.29	0	18 
118.51	0	18 
119.82	0	18 
121.23	0	18 
122.73	0	18 
124.04	0	18 
125.26	0	18 
126.65	0	18 
127.86	0	18 
129.08	0	18 
130.38	0	18 
131.69	0	18 
133	0	18 
134.41	0	18 
135.7	0	18 
137.01	0	18 
138.23	0	18 
139.43	0	18 
140.65	0	18 
141.94	0	18 
143.16	0	18 
144.36	0	18 
145.76	0	18 
146.98	0	18 
148.18	0	18 
149.4	0	18 
150.8	0	18 
152.1	0	18 
153.32	0	18 
154.61	0	18 
155.92	0	18 
157.24	0	18 
158.43	0	18 
159.75	0	18 
161.15	0	18 
162.37	0	18 
163.67	0	18 
164.98	0	18 
166.18	0	18 
167.39	0	18 
168.69	0	18 
169.89	0	18 
171.1	0	18 
172.42	0	18 
173.73	0	18 
174.93	0	18 
176.14	0	18 
177.46	0	18 
178.66	0	18 
180.05	0	18 
181.26	0	18 
182.57	0	18 
183.79	0	18 
185.2	0	18 
186.49	0	18 
187.71	0	18 
188.91	0	18 
190.22	0	18 
191.53	0	18 
192.73	0	18 
193.95	0	18 
195.15	0	18 
196.35	0	18 
197.66	0	18 
198.96	0	18 
200.17	0	18 
201.39	0	18 
202.7	0	18 
204	0	18 
205.21	0	18 
206.41	0	18 
207.63	0	18 
208.92	0	18 
210.23	0	18 
211.45	0	18 
212.75	0	18 
214.06	0	18 
215.26	0	18 
216.66	0	18 
217.98	0	18 
219.19	0	18 
220.49	0	18 
221.8	0	18 
223.02	0	18 
224.31	0	18 
225.53	0	18 
226.82	0	18 
228.04	0	18 
229.24	0	18 
230.45	0	18 
231.65	0	18 
233.06	0	18 
234.47	0	18 
235.69	0	18 
236.89	0	18 
238.29	0	18 
239.7	0	18 
240.92	0	18 
242.12	0	18 
243.33	0	18 
244.74	0	18 
246.15	0	18 
247.35	0	18 
248.66	0	18 
249.86	0	18 
251.17	0	18 
252.48	0	18 
253.87	0	18 
255.19	0	18 
256.48	0	18 
257.81	0	18 
259.12	0	18 
260.53	0	18 
261.92	0	18 
263.12	0	18 
264.45	0	18 
265.65	0	18 
266.86	0	18 
268.16	0	18 
269.47	0	18 
270.69	0	18 
272.1	0	18 
273.49	0	18 
274.8	0	18 
276.21	0	18 
277.5	0	18 
278.81	0	18 
280.03	0	18 
281.34	0	18 
282.54	0	18 
283.85	0	17.2 
285.07	0	17.2 
286.48	0	17.2 
287.68	0	17.2 
288.88	0	17.2 
290.09	0	17.2 
291.29	0	17.2 
292.6	0	17.2 
293.82	0	17.2 
295.23	0	16.4 
296.52	0	16.4 
297.74	0	16.4 
299.03	0	17.2 
301.15	0	17.2 
302.57	0	17.2 
303.98	0	17.2 
305.41	0	17.2 
306.68	0	17.2 
307.99	0	17.2 
309.19	0	17.2 
310.41	0	17.2 
311.72	0	17.2 
313.02	0	17.2 
314.42	0	17.2 
315.74	0	17.2 
317.05	0	17.2 
318.36	0	17.2 
319.77	0	17.2 
321.06	0	17.2 
322.28	0	17.2 
323.78	0	17.2 
325	0	17.2 
326.29	0	17.2 
327.61	0	17.2 
328.92	0	17.2 
330.12	0	17.2 
331.43	0	17.2 
332.63	0	17.2 
333.96	0	17.2 
335.25	0	17.2 
336.56	0	17.2 
337.76	0	17.2 
339.17	0	17.2 
340.48	0	17.2 
341.68	0	17.2 
343	0	17.2 
344.31	0	17.2 
345.6	0	17.2 
346.91	0	17.2 
348.32	0	17.2 
349.54	0	17.2 
350.83	0	17.2 
352.24	0	17.2 
353.55	0	17.2 
354.87	0	17.2 
356.16	0	17.2 
357.38	0	17.2 
358.69	0	17.2 
359.98	0	17.2 
361.3	0	17.2 
362.7	0	17.2 
364.02	0	17.2 
365.33	0	17.2 
366.53	0	17.2 
367.94	0	17.2 
369.25	0	17.2 
370.54	0	17.2 
371.76	0	17.2 
373.07	0	17.2 
374.37	0	17.2 
375.77	0	17.2 
376.99	0	17.2 
378.19	0	17.2 
379.41	0	17.2 
380.61	0	17.2 
382.01	0	17.2 
383.32	0	17.2 
384.52	0	17.2 
385.84	0	17.2 
387.05	0	17.2 
388.35	0	17.2 
389.66	0	17.2 
391.07	0	17.2 
392.36	0	17.2 
393.67	0	17.2 
394.99	0	17.2 
396.3	0	17.2 
397.61	0	17.2 
398.91	0	17.2 
400.12	0	17.2 
401.43	0	17.2 
402.73	0	17.2 
403.95	0	17.2 
405.24	0	17.2 
406.55	0	17.2 
407.96	0	17.2 
409.18	0	17.2 
410.38	0	17.2 
411.59	0	17.2 
413	0	17.2 
414.2	0	17.2 
415.51	0	17.2 
417	0	17.2 
418.21	0	17.2 
419.43	0	17.2 
420.63	0	17.2 
421.94	0	17.2 
423.25	0	17.2 
424.57	0	17.2 
425.77	0	17.2 
427.17	0	17.2 
428.37	0	17.2 
429.59	0	17.2 
430.79	0	17.2 
432.2	0	17.2 
433.51	0	17.2 
434.72	0	17.2 
435.92	0	17.2 
437.12	0	17.2 
438.34	0	17.2 
439.65	0	17.2 
440.95	0	17.2 
442.26	0	17.2 
443.47	0	17.2 
444.77	0	17.2 
446.08	0	17.2 
447.28	0	17.2 
448.5	0	17.2 
449.81	0	17.2 
451.11	0	17.2 
452.42	0	17.2 
453.62	0	17.2 
454.83	0	17.2 
456.03	0	17.2 
457.34	0	17.2 
458.56	0	17.2 
459.76	0	17.2 
461.07	0	17.2 
462.37	0	17.2 
463.68	0	17.2 
465.09	0	17.2 
466.3	0	17.2 
467.69	0	17.2 
469.01	0	17.2 
470.3	0	17.2 
471.63	0	17.2 
472.93	0	17.2 
474.24	0	17.2 
475.55	0	17.2 
476.96	0	17.2 
478.17	0	17.2 
479.58	0	17.2 
480.88	0	17.2 
482.09	0	17.2 
483.29	0	17.2 
484.6	0	17.2 
485.82	0	17.2 
487.12	0	17.2 
488.33	0	17.2 
489.55	0	18 
490.84	0	18 
492.15	0	18 
493.45	0	18 
494.67	0	18 
495.88	0	18 
497.18	0	18 
498.47	0	18 
499.78	0	18 
501	0	18 
502.2	0	18 
503.42	0	18 
504.71	0	18 
506.12	0	18 
507.34	0	18 
508.63	0	18 
509.85	0	18 
511.16	0	18 
512.45	0	18 
513.77	0	18 
514.98	0	18 
516.28	0	18 
517.49	0	18 
518.69	0	18 
519.91	0	18 
521.21	0	18 
522.53	0	18 
523.83	0	18 
525.03	0	18 
526.24	0	18 
527.54	0	18 
528.87	0	18 
530.07	0	18 
531.36	0	18 
532.58	0	18.8 
533.8	0	18.8 
535.19	0	18.8 

Thats the data. I can start a new thread if needs be. 
Cheers 
Aaron


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## AaronGS (Jan 4, 2011)

Any ideas on my codes?


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## AaronGS (Jan 4, 2011)

Well my codes are gone and fuel trim only about +5% now. All since replacing a vac pipe. Car still feels underpowered.

Animaniac - is there anyway to test the MAP sensor?

Dana - thanks for all the help via PM. cheers.


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## pfb (Nov 28, 2005)

Having some of my own lean fuel trim errors...

Details in this thread:

http://forums.vwvortex.com/showthread.php?5182708

Seems like lots of well informed people on this thread, thought they might take a look!


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## Matt 337 (Apr 10, 2009)

I ran block 032 and I was getting 0.4% and 0.8% then I cleared some intermittent misfires drove the car for about 30 miles rescan block 032 and I'm getting 0.0% and 1.6% shouldn't the first number be something other than 0?


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## djunited (May 29, 2011)

hi, i have a euro spec mk6 gti with revo stage 1 and an itg intake. 
until recently, lambda control adaptation idle showed -1.0% and partial showed -0.7%,or something like that.
last night after doing some runs with my friends in 30Celcius and very humid weather, i logged measuring block 32 and adaptation idle showed -1.6% while partial showed -7.0%. i have never seen that value since i had a k&n intake on,the value was -14.6%.(turbulence)
i have also not seen this value 2 weeks since i got the itg installed.


after driving around the next day,idle is now -0.4% and partial is -8.6%. 
also logged my friend's mk6 gti with the exact same revo file but stock intake.we were both racing yesterday and his idle is -1.4% but partial is normal at -2.0%.
he has not driven the car since our races.

what do you suspect is going on here?dv leak (G revision)?intake leak? i noticed my intake is louder than before with a more pronounced flutter.


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## bunnyspeed (Jul 8, 2003)

recently scanned and had:

first block +1.5%
second -9.4%

thoughts?

GIAC, SAI, N249 delete....


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## tybo (Aug 18, 2011)

Hello all , 

This is my first post here.
I am Tybo, I am from France. 
SO excuse me if I am not very good with the technical terms.

As I just did a test with a VCDS soft (release 805) I was wondering about the health of my S3 1.8T AMK engine with an ABT remap

I have MAF low values (actually I have 170 g/s) and my boost pressure is around 2.0bars , and the nominal pressure should be at 2.55 ( but i have still stock exhaust)

I took an apointment in an Audi dealer so check what's wrong, but it's within 15 days... 

Then I discovered the 032 channel . 

And I think I have a problem : 
I reached this channel few instants after I started the engine and the values were 0/0 . 
Then after the engine was warmed , I had few hundred meters and in full throttle I could reach -1.6% on the second lambda window, and still 0 on the first. 
Then at idle rpm -0.8% was remaining at the lambda at the right side and still 0 on the first lambda cell. (i had 0.2% jsut a second when engine was cold , but never came back) 

I am little afraid because I read in this topic that having 0/0 values at startup means that one cleared DTC errors or one have a problem ... 
And I cleared the DTC errors but weeks ago !! And i made few hundreds of kilometers before accessing channel 032.

I had : lambda sensor because I made the one near the turbo being replaced , and the MAF because I made it changed too. 
Since I cleared , I have nothing as DTC excepted the intrusion warning , I didnt deleted them I think...

My battery is okay, no need to enter the radio code each time I want to listen to music :laugh:

So I really have a problem? 
What could explain my 0/0 values? 

I have to say that I have a orange warning due a bad brake pad sensor. Maybe this kind of warning reset the ECU values??????

Thank you for you help ! :wave:


Tybo


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## manyDUBs (Dec 26, 2002)

*032 logs Revo stage 3, primary channel settings...*

Hello,

I have a AWP 1.8T motor with Stage 3 REVO SW installed:
GT2871R turbo

My 032 Vag Com logs read: +0.8 & +5.5 which indicated a lean mixture

So, I adjusted the primary fuel channel in Unisettings to 10%

My second reading was then: -0.6 & -0.6 

Should I keep it at that, since both at idle and when driving the mixture is now a little rich?

Would it be safer to richen the primary a little more?

What about the secondary fuel channel?


The reason I started testing was after coming out of gear and go to idle whilst driving, there is a slight dip in RPMs, it steadies out and does it a little bit.

Thanks


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## Cabby2litre (May 22, 2011)

Hey y'all..... How about my situation. My short term is maxed at -26.6 and long term is steady at +3.2...


I've checked everything and it's obviously not a vac leak since it's trying to take away fuel. It hunts all the time at idle until it finally just kills it self. At a loss at this point.. it's a 2001 Jetta Wolfsburg 1.8t



Anybody that has any ideas would be appreciated.


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