# I'm getting no reading from the DPR.



## SlowMotion (Jun 9, 2002)

Finally got my test harness from TT and connected to my DPR to get my values. I follow the steps for my DMM but I'm getting no reading.
Meter reads 0.00 in the 200 mA setting, but occasionally it'll go up to 0.01 and then gives me a - 0.00 reading ( I'm assuming the DPR values changed and went to the - side)
I unplugged the OX sensor to get and idea of were my mixture were and they were lean or 0.00 V. I turn the adjusting screw and got it to bounce from 0.2v to 0.7v were it should be a bit richer and better running.
Any other way to test the DPR functionality ? is my harness bad or just wtf I'm doing wrong here.


----------



## ziddey (Apr 16, 2006)

*Re: I'm getting no reading from the DPR. (SlowMotion)*

leave the dpr plugged in and set the mixture so that you get around 0.7v from the o2 sensor. then note if there's any change in engine behavior when you unplug the dpr with the engine running. if it runs rough afterwards, then the dpr is functioning. if there is no change in engine behavior, suspect the ecu and grounds


----------



## WaterWheels (Aug 14, 2005)

If everything is connected correctly and on the correct scale then a 0.00 reading would indicate too rich. That you adjusted the volt output of the Lambda sensor to .7 from .2 would indicate just the opposite. Maybe the wires to the multi-meter were backwards and hense the reading??


----------



## ziddey (Apr 16, 2006)

*Re: (WaterWheels)*

With the plugs flipped, you would get a negative reading is all. If your lambda output was 0v, and your dpr was 0ma, that sounds like a lean condition that's not being corrected for. I've seen this happen with broken grounds and bad ecu's. Of course a bad dpr could cause this as well. Take a voltmeter to the two wires going to the dpr.


----------



## WaterWheels (Aug 14, 2005)

What people have or are using for test equipment really does not interest me, but all the Multi-meters I've owned, and some have cost a few cents, none have read negative milliamperes. Just my understanding of the issue, maybe wrong, that if you go highenough it becomes 1 ampere and if you go low enough then, well it's nothing. But enough on that, a reading of 0mA at idle is not too lean. What you are reading is the reaction of the computer to a rich mixture in the exhaust. It is getting a rich signal from the O2 sensor and trying to cut the fuel to lean it out. A bad diferential pressure regulator can and most likely would cause a mixture problem, but it would not effect the reading you get from the ECU, it is reacting to that signal, not creating it.


----------



## SlowMotion (Jun 9, 2002)

*FV-QR*

Thanks guys for all help I really appreciate it.
Mt testing of the oxygen sensor were done with the sensor unplugged from the ecu to get a reading without the ecu trying to correct it.
Yesterday the mixture was so rich that my idle speed were 1000 to 1200 rpm. I didn't have the dmm handy so I went ccw on hte adjustment to bring the idle to back to 900 rpm. Well today the car was hard starting, I mean it took like 5 tries of 5 sec cranking to get it going then the idle was very poor to the point of almost stalling in several occasions. After the car warmed up it seems normal.
Tomorrow I'm going to see if I get a reading from the DPR. I'm going to change the battery of the dmm to see if that works.
BTW the car in question is a 1989 Audi 90 Quattro.


----------



## ziddey (Apr 16, 2006)

*Re: (WaterWheels)*

Negative current means it's flowing in the other direction. I've never watched it personally, but cis-e with idle switch should drop dpr to -50ma for deceleration fuel cutoff.
OP, 89 90q should be cis motronic? I don't remember the spec there but I think it has a centering at 0ma or 2.5ma to provide better driveability in the event there is an ecu failure.
I don't know if cis motronic will go negative to maintain stoich, but i do know cis-e's limits are 0-20ma in closed loop.
Have you been able to get the dpr to register anything? Does unplugging it while the car is running cause any change in engine behavior?
You're not plugging into the 10a unfused port right?

edit: I will have to confirm next time. I have a feeling I'm going to be eating my words about negative current.


_Modified by ziddey at 10:25 PM 4-25-2010_


----------



## mikegabriel (Oct 4, 2007)

Oh wow this is awesome. I just finished a motronic swap into my MK1 and am running into weird idle / running issues when warm. Nice to see that this thread is current cause this is likely my problem.
I don't have a TechTonics harness though, do either of you know the specs on making one? Is it 2 straight wires connecting the same lines on the harness and then splice into one of them for the reading? I'm having a tough time finding specifics on it, most pages are dead.


----------



## ziddey (Apr 16, 2006)

*Re: (mikegabriel)*

The idea is to measure the current going through the DPR. To do so, the ammeter needs to go inline. So instead of hacking into the original wiring, you can build/buy a harness with the necessary female/male plugs to go in between and allow you to hook up the ammeter inline.


----------



## mikegabriel (Oct 4, 2007)

So when I built mine, I used 3 strips of wire...
1 Black, 2 Red.
Black has a spade end and a female plug end allowing it to be connected from the harness to the DPR.
One red has a spade and a female plug end allowing it to be connected from the harness to the + Terminal on my DMM (V. Ohm. mA) set to 200m on Amperage.
2nd red has two female plugs allowing it to be connected from the - Terminal on the DMM to the DPR. - is in the COM port on the DMM.
Now I have a feeling something isn't right between this.


----------



## 1985gticis (Mar 11, 2010)

*Re: (ziddey)*

where can you buy this harness or the correct plugs? and is it possible for the DPR to be bad intermittently? or if its bad its bad?


----------



## WaterWheels (Aug 14, 2005)

No, I doubt you'll have to eat your words. After thinking about things later, and you point it out here, you can recieve a negative reading during cut-off, so I guess it is possible to have negative millamps. Just seems to make no sense as you are reading "force or the push behind the voltage" and not voltage, right? But that brain fart on my part really changes nothing as I have never had a system read negative mA when at idle, o.o was always the lowest. I have built a few cables and have done connected them backwards a few time with the result being 0.0mA (dead battery in the multi-meter also read 0.0mA). 
Somewhere I have a simple drawing of how one is hooked-up and should also prove as an example of haow to build one. I'll try to locate it and post it up. You can purchase the connectors and wire ends from VW, but slavage yard harnesses can be stripped for the parts also.


----------



## SlowMotion (Jun 9, 2002)

*Re: (ziddey)*

The value for the Audi should be 0 mA but it should be jumping around that area.
Later on today i'm going to pick up 15k ohms of resistors at radio shack to simulate a cold start and check my cold start valve. The car has become real hard to start when cold with real low idle speed for about 5 mins then it goes back to normal.
As for the harness question, one wire goes from dpr to harness and the other will be split so you can connect the dmm inline. I tried both setting on the dmm the mA fused and the 10 A unfused with the same results 0.00 mA with no change even with the adjuster being pushed down.
When the DPR is unplugged the engine will get rough so its working.


_Modified by SlowMotion at 6:20 AM 4-26-2010_


----------



## mikegabriel (Oct 4, 2007)

Here's the best diagram I found:








So 3 wires, one solid and 2 with the DMM inline. That's what I built and got no reading however I have since discovered that too rich will also read 0.00 so maybe that is my problem.


----------



## WaterWheels (Aug 14, 2005)

That's the same drawing I was going to find in my stuff. Only thing it does not help with is which wire is which.


----------



## mikegabriel (Oct 4, 2007)

I'm trying to take a reading of voltage off the single wire on the O2 sensor itself. I found somewhere on here that a decent reading should be around 0.80 VDC. Currently I am reading 0.00 when warm or cold.
The two pin harness on the O2 is supposed to be heating elements as per Bentley but there is no voltage on them at all, any idea if there is supposed to be? I'm wondering if I found my problem but I can't find any answers so far.


----------



## SlowMotion (Jun 9, 2002)

*Re: (mikegabriel)*

The o2 sensor comes in after a couple of minute of starting the engine.
With a cold engine take the DMM and set it to volts and there should be 13V at the harness from the ecu. If there's no power at the heating element wire, inspect the harness for a break. If there's no signal from the o2 sensor after the car warmed up, your o2 sensor could be dead.
As for the voltage coming from the o2 sensor, once the car warms up the o2 will kick in. The voltage should be jumping between 0.7v and 0.2v. The optimal signal will be 0.47v but you won't get to see that on a DMM. Try a analog meter or a o2 sensor gauge with at least 8-10 leds and always disconnect the signal wire from the ecu to adjust your mixture.
Now I think that I found my problem

__
Image uploading. Refresh page to view








the fuse on the DMM was blown







now I need to find the 0.2A 250V fuse and take a jab at it again.


----------



## mikegabriel (Oct 4, 2007)

Good reply! Thanks!
Next cold start I will check for 12v on the Red/White wire to the O2 Heating Element.
I'm going to rebuild my test harness using some actual connectors tonight. Also for my knowledge, on my setup my O2 is just off the exhaust header (all of a foot down into the pipe). Would that make any difference?


----------



## SlowMotion (Jun 9, 2002)

*FV-QR*

No difference on where the sensor is mounted.
The sensor needs to heat up really hot like 600F so it could function. The electrical connection are there to help the sensor heat up faster so the ecu could use it signal to help establish your mixture.


----------



## 1985gticis (Mar 11, 2010)

*Re: (mikegabriel)*

am i interpenetrating this diagram correctly? 
leave the ground wire untouched and simply plug the red wired from the dpr into the + end of the multi meter and plug the other wire from the ecu into the - terminal of the multi meter??? sry its not my thread just relevant on here.


----------



## WaterWheels (Aug 14, 2005)

Assuming the red/white wire is the Positive wire (+), not knowing the color off-hand, then yes. You are taking the reading as things pass "through" the meter. The return is un-important and the wire is part of the small harness just to keep things the same lenght sort of.


----------



## mikegabriel (Oct 4, 2007)

Yeah the reason I wasn't getting a reading was my fuse in my multimeter, replaced it and it is now reading. However... Can anyone point me in the right direction? Here's a video of my reading, you'll see it bounces all over from +36 to -16. Grounding the signal wire doesn't make any difference, unplugging the O2 doesn't do anything and plugging it in doesn't change. This starts happening as soon as the car warms up.
http://www.flickr.com/photos/m...18366/


----------



## SlowMotion (Jun 9, 2002)

*Re: (mikegabriel)*

Is that the signal from the o2 sensor ?
If so you must have a vacuum leak somewhere as is indicated by the very lean -16 , -12 reading, then it jumps to the positive side which means the DPR is trying to richen up the mixture.
With the car warmed up disconnect the signal wire from the ecu, grab your 3mm hex key and turn your DPR adjustment clockwise 1/8 turn. Blip the throttle and let it settle and check the reading again. Don't forget to take out the hex key before blipping the throttle.
The reading also shows that the o2 sensor is working, just look at how fast it's changing. Your goal is to make the reading on the o2 sensor positive to around 0.7v-0.2.
Is that system a cis-e ? because I'm giving values based off cis-e


----------



## mikegabriel (Oct 4, 2007)

Yea it's CIS-E Motronic swapped into a MK1 Rabbit.
The reading is off the DPR, I just rebuilt my harness and changed the fuse in my DMM and it works now.
There are no vacuum leaks, I've plugged all tap off that I am not using. 
3mm Hex has no effect, 1/8 turns does nothing to change how the car runs. I'm not sure what the previous owner had it running like but I am speculating like crap. I can turn the 3mm hex as far as I want until it eventually stalls out, neither direction makes any improvement in the reading (It bounces the same way all the way through).
I'm at a loss as to whats wrong. Unplug the DPR and the car runs great, just burns a lot of fuel since the computer isn't adjusting.


----------



## SlowMotion (Jun 9, 2002)

*Re: (mikegabriel)*

CIS- motronics calls for 10mA.
I had some issues with the DPR not adjusting how my car ran and it was due to vacuum leak. I had a plastic nipple break off and that was my issue, once I fix that it was all good.


----------



## mikegabriel (Oct 4, 2007)

Hmm, I swapped a different DPR onto it today since it's quick and made no difference.
I've sprayed carb cleaner and haven't found any leaks.. I'm blocking off most of the vacuum lines on the intake boot. Only have one that goes to the IAC, the other 4 (2 near throttle body and 2 by air boxes) are plugged. The cold start valve's vacuum line is connected to the same hose as the IAC.
Other than that, there one very thin nipple on the back of the throttle body, it's plugged. The idle screw on the throttle body is secure and all the way in. The FPR is connected to the airbox (Not in vacuum).
Trying to think what else but I think that's everything.


----------



## ziddey (Apr 16, 2006)

*Re: (mikegabriel)*

From what I remember, cis motronic has a lower nominal dpr current, not 10ma. This was to provide driveability in the event the ecu goes out, or there's some other problem preventing the dpr from being powered. 2.5ma possibly.
When you unplug the o2 sensor, the dpr should stop oscillating. I haven't seen dpr behavior like in your video, but if I had to speculate, I'd guess that the o2 sensor is garbage. Failed "slow to react". In closed loop, the ecu is constantly switching the mixture around stoich, but that depends on a fast responding o2 to know when to switch over. If it responds too slow, the ecu will overcompensate extremely on either end.
So it looks like cis motronic can reverse current to further trim fuel. cis-e can only lean out to 0ma.


----------



## mikegabriel (Oct 4, 2007)

Alright so I pulled my O2 out completely and cleaned it off (It was completely black). Put it back in and tightened it up really good. 
Hooked up the DPR without my test harness and let it warm up. It never started sputtering. It ran for at least 15 minutes and never acted up. Rad fan ran at least once.
I hooked my DMM to the black lead on the O2 and it only registered 0.40 VDC. So I put a 3mm hex in and gave a 90 degree turn, still 0.40 VDC. Turn it a full 360 from original, still 0.40 VDC.
I reverted it back to where I started but why would the voltage not change when the mixture is altered. The 360 degree turn made it run rich and you could hear the engine react to it.
If you guys suggest a different O2, I'll go buy one, just want to be sure before I shell out the cash.


----------



## ziddey (Apr 16, 2006)

*Re: (mikegabriel)*

so you're unplugging the o2 sensor wire and hooking that up to a voltmeter, and hooking up to any ground to measure it? and it's 0.40v full time no matter if you rev it, change the mixture, or whatever? sounds like a bad o2 sensor for sure.

for the time being, you can leave the o2 sensor unplugged, and crudely tune the mixture by ear/feel.


----------



## mikegabriel (Oct 4, 2007)

I rechecked it and it appears that O2 is actually doing 0.00 V and that 0.40V is coming off the ECU.. The spade that plugs into the O2 signal has the 0.4 volts when unplugged.
Is that normal? I know from all my diagrams that it's pin #7 on the ECU.


----------



## ziddey (Apr 16, 2006)

*Re: (mikegabriel)*

yes, that is normal.
the o2 output stays at 0v? is the heater plugged in, and the car run for long enough to get the o2 sensor up to temperature? fattening the mixture will not increase the output?


----------



## mikegabriel (Oct 4, 2007)

Correct. I had made a topic in the 16v Forum about the heater wire cause the Bentley doesn't really state much.
What I have figured out is the two wire plug. Brown is Ground & the Red/White is supposed to be 12v. When I hooked my DMM to it, there was ground on Brown but nothing on the Red/White. Someone suggested that it only gets 12v for a short while when it's cold and since I tested voltage when warm that could be why it showed nothing.
Now, I am not sure if that's true so I wired 12v right off the battery to it, as soon as I did that, I was able to take a reading off the signal wire (when unplugged from harness).
When I started the car after that, with the DMM hooked to the signal wire (Which was unhooked from the ECU still). It climbed by 0.01 all the way until about 0.45 and that's where it stopped climbing.
Doing this test, I had the DPR unplugged so I plugged the DPR in and immediately the engine started to surge and the meter drop from 0.45 to 0.11 and then -0.20 and then back to 0.10 and then back into the negatives. Unplug the DPR and it starts to climb back to 0.45. ** This is still VDC off the O2 Signal
I threw a 3mm hex into the adjuster screw and gave it a turn and saw no change in the voltage off the O2 Signal.


----------



## ziddey (Apr 16, 2006)

*Re: (mikegabriel)*

dpr should be at a fixed value when cts is up to temp and o2 is unplugged. the only thing that could affect it would be the potentiometer on the other side of the fuel distributor (maybe. i'm not completely sure of how the potentiometer comes into play)
i'm not sure if nominal for cis motronic is 0ma or 2.5ma, but whatever it is is what you should tune the mixture so it oscillates around that (once you get to that point).
can you post a video of dpr behavior with the o2 sensor unplugged (car in open loop)?


----------



## mikegabriel (Oct 4, 2007)

I just have to step out for a few minutes, as soon as I get home I'll grab a fairly extensive video with all the tests I can show. I'll PM you when it's up.
Also I have been following this guide: http://members.dslextreme.com/....html
It does state that stock settings are:
2.0 16V motronic-averaging 2.5mA.


----------



## ziddey (Apr 16, 2006)

*Re: (mikegabriel)*

90 degrees is a HUGE amount when talking about the mixture screw. I'm surprised at how wide the valid dpr range is for cis motronic. For cis-e, the operating range in closed loop is 0-20ma.
$92 is way too expensive. http://www.autohausaz.com/sear...ensor
the direct replacement version is only $63 there. I can't remember off hand, so you'd need to do some searching, but there's a mustang sensor that'd work for our cars that's only $30 for the universal.
you could also go the unheated route: http://www.autohausaz.com/sear...ensor
then, it's $15 for the sensor. Worth a shot if you're looking to be cheap. The $15 one is what I got for my cis-e vw. It takes a little longer for it to heat up, but once it does, it should be the same. If the o2 sensor is on the manifold, it should work ok. 
I said I'd stop recommending the unheated version because I ran into problems with mine, but I might have just received a bad sensor. I used it for almost a year before switching to a heated one from my parts car. I noticed that at idle, sometimes the sensor would fall asleep, and the car would go full rich (20ma), and other times, it'd do a "walk" where the dpr would go from 10ma down to 7ma, snap back to 10ma, and fall again, instead of proper oscillation. Lots of other people are doing it though and having no problems, so I don't know.
What's up with your o2 sensor wire from the ecu? I can't really tell from the picture, but the original one should be a fairly thick coax, with the outer wire ground for noise suppression.
I'm wondering why there's no o2 heater power. Check your fuses maybe?
So when you manually apply power to the heater, and have the o2 sensor disconnected from the ecu, can you measure the sensor and get the voltage to change? or is it just 0.4v no matter what?
With the o2 sensor unplugged, you get a fixed 15ma through the dpr?? Is the CTS known good? You can get a proper resistor to shunt the connection to simulate a warm engine. I've gotten away with using a paper clip to fully short it, but people say not to do that. Either way, you'll want to make sure the CTS isn't somehow sending a varying signal. I don't know what a bad potentiometer would do, but I do know you can unplug it and run the car fine, so you can do that to rule it out.
Basically, what we're looking for for starters is to have a fixed dpr reading with the o2 sensor unplugged. Then, if you can get any functionality out of the o2 sensor at all, set the mixture (you need to pull the allen key out and blip the throttle between settings) so you read roughly 0.7v on the o2 sensor. Then, you should be able to leave the o2 sensor unplugged and run the car like that until you get a new sensor.


----------



## mikegabriel (Oct 4, 2007)

_Quote »_What's up with your o2 sensor wire from the ecu? I can't really tell from the picture, but the original one should be a fairly thick coax, with the outer wire ground for noise suppression.

Just want to comment on this really quick. There used to be the thick plug but when I was inspecting wires today I noticed it was only hanging on by 2 or 3 copper wires, the rest had broken off. So I cut it and put a new end on it. The ground that surrounds it is currently grounded to my throttlebody since I want to make the car run before I start making things look pretty and organized.
Other than that, the rest of your post makes sense, unfortunately I wont have any time to play around with it further until Saturday.
The problem with O2's is they are cheap in the USA, not in Canada


----------



## ziddey (Apr 16, 2006)

*Re: (mikegabriel)*

there's got to be an "offlabel" use bosch sensor you can get for cheaper. or maybe try the fs sections of the forum.
as for the ground around the o2 signal wire, i don't think that actually hooks up to anything, so you don't need to hook it up to the tb. our o2 sensors ground through the manifold.
fwiw, you should be able to get the car to run perfectly fine with the o2 sensor unplugged. of course an o2 sensor helps in tuning to that spot.


----------



## SlowMotion (Jun 9, 2002)

*FV-QR*

Got my issues resolve !!!!!
I learned that tuning with the o2 sensor is much easier than the DPR alone. Somehow I could get the DPR signal to get below 10mA, so instead of wasting time with it I just went to the o2 signal disconnected from the ecu. Got the signal to bounce between .75v - .20v and then check the DPR signal and what do you know it was at 2ma !! just a small adjustment of the 3mm screw and had it at 0 mA bouncing to 3mA and -1mA.
The DPR setting will affect your starting!! The car hard to start because the DPR signal was over 10 mA. Once adjusted to 0 mA the car started perfect on cold/hot.


----------



## mikegabriel (Oct 4, 2007)

Alright so I swapped a bunch of parts I grabbed off a junkyard Passat a couple weeks ago. 

New Fuel Dizzy, ISV and ECU. 

Same problem. So I guess that either leads me to Wiring, CTS or O2 Sensor. 

O2 being the most expensive, to purchase and this O2 being brand new. Has anyone got a way to test the signal wire to make sure it's sending a signal properly. For example if I was to ground the signal wire, what type of reading could I expect to see on the DPR Test Harness.


----------



## ziddey (Apr 16, 2006)

I don't know the upper limits of cis-motronic, but cis-e will climb until it hits 20ma and stop there, assuming a warm cts.


----------



## mikegabriel (Oct 4, 2007)

Yeah when it was cold and I hooked the meter up and started it, it was 20ma, then dropped 1ma every second until it hit about 5ma and then started bouncing all over the place.

Doesn't make any difference if O2 is plugged or unplugged so I have a feeling it's not the O2 sensor. I have gathered from what I have read the car will run fine without an O2 sensor, just wont have that on-the-fly adjustment. Mine sucks ass once it heats up, regardless of O2 or not.

Coolant temp sensor might be a possibility, it passes the graph test in the Bentley but I guess who's to say it's still not fouling it's signal once it gets warm.

Other than that, I'm sure wishing Vortex still had its archive up and running haha.


----------

