# TECH: Decode Secondary Air Injection Pump in your 2.0



## tdogg74 (Mar 1, 2002)

This post is to decode your secondary air pump out of your OBDII 2.0 Golf/GTI, Jetta &Cabrio. 
****Please note, I am in NO WAY suggesting you disable the SAI pump to accomidate after-market superchargers, cutom intake manifolds, or to simply remove it because the pump sh*t the bed. The SAI pump is part of the emissions system of the car and is a Federal offense to remove any emission equipment that came from the factory. The information given is mainly for engine swaps into earlier generation VW's that did not come with the pump originally.







****

There are ECU coding tables on page ST-25 of the Bentley manual that list the different coding states of the car's ECU. First table is the code for manual/auto tranny. Second table is for OBDI cars with/without EGR. 
The bottom paragraph gives the code to either equip or unequip the secondary air injection pump. The first two codes are TIER 1 & Tier 2. This represents an ECU NOT coded for the air pump. TLEV 1 & TLEV 2 ARE for ECU's coded for an air pump. I am not positive about the Cabrio's. Looking at that table woul lead me to believe that all Cabrios came with a SAI pump. IMHO, changing the coding to 0000 would work because its the same as the Golf/Jetta. 
You will need a registered version of VAGCOM to perform this change. Simply follow the directions at the bottom of the table and you will be all set. http://****************.com/smile/emthup.gif


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## PBWB (Sep 12, 2004)

*Re: Decode Secondary Air Injection Pump in your 2.0 (tdogg74)*

mines a 97 and has no SAI, just thought i'd throw that out there. not all of em came with it.


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## redskins98 (Oct 6, 2005)

*Re: Decode Secondary Air Injection Pump in your 2.0 (PBWB)*

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


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## vwboomer2 (Jan 26, 2003)

*Re: Decode Secondary Air Injection Pump in your 2.0 (redskins98)*

Almost seems kind of a random thing. My car came with it, but I replaced the ECU with one from a car that didn't have it. Before I found out how to decode it for free


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## randallhb (Sep 17, 2002)

*Re: Decode Secondary Air Injection Pump in your 2.0 (tdogg74)*


_Quote, originally posted by *tdogg74* »_I am not positive about the Cabrio's. Looking at that table woul lead me to believe that all Cabrios came with a SAI pump.

I checked the VW Repair Manual and Cabrios shoud set it to 2 or 3 depending on manual/auto tranny.
I tried to find this info for MK4, but the MK4 ECUs can only be coded for tranny type, abs and airbags. So I believe here you have to change the ECU.


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## tdogg74 (Mar 1, 2002)

*Re: Decode Secondary Air Injection Pump in your 2.0 (randallhb)*

bump


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## ll Black Blurr ll (Sep 24, 2004)

*Re: Decode Secondary Air Injection Pump in your 2.0 (randallhb)*


_Quote, originally posted by *randallhb* »_I tried to find this info for MK4, but the MK4 ECUs can only be coded for tranny type, abs and airbags. So I believe here you have to change the ECU.

Is this true? Anyone else try it?


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## vasillalov (Nov 5, 2003)

*Re: Decode Secondary Air Injection Pump in your 2.0 (v-tecs suck)*


_Quote, originally posted by *v-tecs suck* »_Is this true? Anyone else try it?

I've looked in the MK4 Bentley and I did not see any options for recoding. However, I was tired and not too persistant in my search...


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## jfreethy (Apr 12, 2006)

*Re: Decode Secondary Air Injection Pump in your 2.0 (vasillalov)*

Couldnt you just find out the resistance and put a resistor in its place.


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## ll Black Blurr ll (Sep 24, 2004)

*Re: Decode Secondary Air Injection Pump in your 2.0 (jfreethy)*

how would i do that?? I'm open to anything i just don't want to take it out and have a CEL


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## jfreethy (Apr 12, 2006)

*Re: Decode Secondary Air Injection Pump in your 2.0 (v-tecs suck)*

my pump is dead and it give me a CEL ... for now its just sitting in there... as it doesnt really do anything but heat up the cat


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## ll Black Blurr ll (Sep 24, 2004)

*Re: Decode Secondary Air Injection Pump in your 2.0 (jfreethy)*

hell yea i hate that thing! hey jfreethy do you have a vag com?


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## jfreethy (Apr 12, 2006)

*Re: Decode Secondary Air Injection Pump in your 2.0 (v-tecs suck)*

nope ....







I have to go to autozone







for now tho... maybe by the end of the month i will buy it


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## ll Black Blurr ll (Sep 24, 2004)

*Re: Decode Secondary Air Injection Pump in your 2.0 (jfreethy)*

Alright make sure u try the write up that tdogg wrote and let us all know! Hows the car run/drive with the air pump gone?


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## elRey (May 15, 2001)

*Re: Decode Secondary Air Injection Pump in your 2.0 (jfreethy)*

I believe a CEL can be thrown for 2 reasons.
1) if you remove the SAI relay. The code will be something about an "open circuit"
2) if the ECU runs a test and detects that O2 levels don't indicate that
the SAI pump is running. Code will be something like "incorrect flow detected"

The first can be avoided by a resistor or just leaving the relay in.
But the 2nd can not be avoided.... at least not easily. You would have to 
alter the O2 sensor signal whenever the SAI pump is suppose to run.




_Modified by elRey at 8:42 AM 5-1-2006_


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## jfreethy (Apr 12, 2006)

wil do


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (jfreethy)*

AIR PUMPS ARE SOOO GAY!!!


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## independent77 (May 23, 2003)

*Re: (v-tecs suck)*


_Quote, originally posted by *v-tecs suck* »_AIR PUMPS ARE SOOO GAY!!!
















wow, thanks for your constructive comments.


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (independent77)*

Sorry


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## the_q_jet (Mar 19, 2005)

coool


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## tdogg74 (Mar 1, 2002)

Come on guys, keep my post on-topic. 
If someone can get some concrete MKIV info, Ill edit my first post with it.


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (tdogg74)*

If anyone has a vag com near RI i can be the test subject so we can prove if this ISH works on the mk4....
Ive also contacted the guy who put my software in (upsolute), RM Pro Tune, USRT (to see if they have any new info on the aeg air pump issue) and C2 motorsports, ill let you guys know the info as i get it....




_Modified by v-tecs suck at 9:28 PM 5-1-2006_


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## elRey (May 15, 2001)

*Re: (tdogg74)*

Recoding for Sec Air Injector/Pump








From the man himself (Uwe) referring to MK4

_Quote, originally posted by *Uwe* »_Coding can only enable or disable certain pre-defined options. No option exists to "code away" emissions equipment that was standard on all engines like yours.
-Uwe-



_Modified by elRey at 7:03 PM 5-1-2006_


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (elRey)*

Yes we are looking for mk4.....


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## elRey (May 15, 2001)

*Re: (v-tecs suck)*

edited my post above


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## tdogg74 (Mar 1, 2002)

*Re: (elRey)*


_Quote, originally posted by *elRey* »_Recoding for Sec Air Injector/Pump








From the man himself (Uwe) referring to MK4
_Modified by elRey at 7:03 PM 5-1-2006_

What's your point with this post?


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## elRey (May 15, 2001)

*Re: (tdogg74)*


_Quote, originally posted by *tdogg74* »_
What's your point with this post?









From the man himself (Uwe) *referring to MK4*

_Quote, originally posted by *Uwe* »_Coding can only enable or disable certain pre-defined options. *No option exists to "code away" emissions equipment that was standard on all engines like yours*.
-Uwe-

i.e.
Since ALL MK4 engines came with SAI, there is NO non-SAI equipped cars. Thus NO non-SAI code to recode with.



_Modified by elRey at 8:04 PM 5-1-2006_


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## tdogg74 (Mar 1, 2002)

Ah...gotcha.

Well, there you have it folks. Can't disable it on the MKIV.


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (tdogg74)*








http://****************.com/smile/emthdown.gif What the eff am i gonna do now?


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## pwnt by pat (Oct 21, 2005)

run with an orange cel.
orange = emissions.
Or just relocate the airpump


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## randallhb (Sep 17, 2002)

*Re: (tdogg74)*


_Quote, originally posted by *tdogg74* »_Well, there you have it folks. Can't disable it on the MKIV.

I might have a solution, I found all part numbers for AEG ECUs in etka, here they are:
AEG	06A 906 018 BG	with cruise control >> 9M-X-999 000	TIER 1
AEG	06A 906 018 FA	with cruise control	9M-Y-000 001	>> TIER 1
AEG	06A 906 018 BH	w/o cruise control >> 9M-X-999 000	TIER 1
AEG	06A 906 018 FB	w/o cruise control	9M-Y-000 001 >> TIER 1
AEG	06A 906 018 BJ	w/o cruise control >> 9M-X-999 000	LEV
AEG	06A 906 018 ET	w/o cruise control	9M-Y-000 001	>> 9M-1-075 840	LEV
AEG	06A 906 018 J	with cruise control >> 9M-X-999 000	LEV
AEG	06A 906 018 ES	with cruise control	9M-Y-000 001	>> 9M-1-075 840	LEV
It might work by changing from the LEV ECU to the corresponding TIER1. 
BTW I found other part numbers for MKIVs DBW 2.0s AZG, AVH, BBW, BEV etc, but the only difference is for manual/auto trannys.


_Modified by randallhb at 10:59 AM 5-2-2006_


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## tdogg74 (Mar 1, 2002)

*Re: (randallhb)*


_Quote, originally posted by *randallhb* »_
I might have a solution, I found all part numbers for AEG ECUs in etka, here they are:
AEG	06A 906 018 BG	with cruise control >> 9M-X-999 000	TIER 1
AEG	06A 906 018 FA	with cruise control	9M-Y-000 001	>> TIER 1
AEG	06A 906 018 BH	w/o cruise control >> 9M-X-999 000	TIER 1
AEG	06A 906 018 FB	w/o cruise control	9M-Y-000 001 >> TIER 1
AEG	06A 906 018 BJ	w/o cruise control >> 9M-X-999 000	LEV
AEG	06A 906 018 ET	w/o cruise control	9M-Y-000 001	>> 9M-1-075 840	LEV
AEG	06A 906 018 J	with cruise control >> 9M-X-999 000	LEV
AEG	06A 906 018 ES	with cruise control	9M-Y-000 001	>> 9M-1-075 840	LEV
It might work by changing from the LEV ECU to the corresponding TIER1. 
BTW I found other part numbers for MKIVs DBW 2.0s AZG, AVH, BBW, BEV etc, but the only difference is for manual/auto trannys.

_Modified by randallhb at 10:59 AM 5-2-2006_


You know what that post says to me? It says "Travis, if they have different ECUs for TLEV and TIER1, then coding can be changed via VAGCOM." http://****************.com/smile/emthup.gif


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## randallhb (Sep 17, 2002)

*Re: (tdogg74)*


_Quote, originally posted by *tdogg74* »_You know what that post says to me? It says "Travis, if they have different ECUs for TLEV and TIER1, then coding can be changed via VAGCOM." http://****************.com/smile/emthup.gif 

Travis as I said before the ECU program in MKIVs AEG only can be coded for ABS, Tranny, and Airbag. I read ALL the repair manual and there was no way to change for the air pump.
Now it is a matter of someone trying to swap their ECU or have it flashed with the other program.


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (randallhb)*

My sources tell me the ecu has to be re-programmed which is illegal (they said i would have to sign some kind of waiver saying my car is not going to be run on the street) or relocate the air pump....


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## randallhb (Sep 17, 2002)

*Re: (v-tecs suck)*

Just get another ECU, immobilizer II ECUs take no more than a seconds to adapt using vag com.

_Quote, originally posted by *http://www.ross-tech.com/vag-com/cars/immobilizer2.html* »_
1. Install the new ECU in the car
[Select]
[17 - Instruments]
[Adaptation - 10]
Leave channel at "00"
[Read]
[Save]

2. [Done, Go Back]
[Close Controller, Go Back - 06]
[Exit]

3. Turn ignition OFF for 15 seconds. Start vehicle.


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (randallhb)*

where do i get that?


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## randallhb (Sep 17, 2002)

*Re: (v-tecs suck)*

http://www.car-part.com, use this criteria:
Year: 2000
Make: Volkswagen Jetta
Part: Engine Computer
Leave the rest at default
Search
Select "Elec Cont Unit (ECU), 2.0L, exc. Calif; w/o cruise control"
Search
You will get a list of part numbers like 06A 906 018 FB


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (randallhb)*

Isnt there a way to just tranfer the data from one of those ecus to yours????


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## misfit77 (Jan 13, 2006)

If I have a SAI, does anyone see any peformance improvements by removing the SAI?
Forget the legal issues.


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## ll Black Blurr ll (Sep 24, 2004)

*Re: (misfit77)*

I heard your car runs fine, but u will just have a CEL


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## scotty_passat (Apr 17, 2001)

*Re: Decode Secondary Air Injection Pump in your 2.0 (elRey)*

I believe actually there is a pressure switch inside the pump, if the pump runs and there are no leaks, pressure builds up and the pressure switch closes...if the pump is bad or doesn't run or there is a major leak in the output pipe no pressure builds and it sets the CEL.
If so a "hack" that fools the pressure switch might be possible...but it may be smart enough to know that the switch should only be on when the pump is commanded to run. (ie jumper or something might trigger a code for the opposite reason)...maybe a relay that turns on with the pump could do it?
Someone with Bentley CD or manual should check the electrical diagrams for the SAI to confirm the pressure switch.
Best solution IMO is to relocate the pump if it is mechanically in the way, even if you fool the ECU if it comes time for an emissions test you may fail.
Many models use SAI, you can probably find some longer hoses and fab a new bracket. Check some of the 1.8T or 2.8l V6 parts.
Here is some inspiration:
http://forums.audiworld.com/a4/msgs/2081138.phtml

_Quote, originally posted by *elRey* »_I believe a CEL can be thrown for 2 reasons.
1) if you remove the SAI relay. The code will be something about an "open circuit"
2) if the ECU runs a test and detects that O2 levels don't indicate that
the SAI pump is running. Code will be something like "incorrect flow detected"

The first can be avoided by a resistor or just leaving the relay in.
But the 2nd can not be avoided.... at least not easily. You would have to 
alter the O2 sensor signal whenever the SAI pump is suppose to run.
_Modified by elRey at 8:42 AM 5-1-2006_


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## elRey (May 15, 2001)

*Re: Decode Secondary Air Injection Pump in your 2.0 (scotty_passat)*


_Quote, originally posted by *scotty_passat* »_I believe actually there is a pressure switch inside the pump, if the pump runs and there are no leaks, pressure builds up and the pressure switch closes...if the pump is bad or doesn't run or there is a major leak in the output pipe no pressure builds and it sets the CEL.

I've been studying wiring diagrams for AZG and AWP for months now.
I have the wiring diagrams up now, and no pressure switch or extra wires
to the pump that would facilitate any kind of sensor/switch in the pump
itself. There's no mention of a pressure switch for SAI system either.
Rey


_Modified by elRey at 6:46 AM 5-3-2006_


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## pwnt by pat (Oct 21, 2005)

_Quote »_http://www.car-part.com, use this criteria:
Year: 2000
Make: Volkswagen Jetta
Part: Engine Computer
Leave the rest at default
Search
Select "Elec Cont Unit (ECU), 2.0L, exc. Calif; w/o cruise control"
Search
You will get a list of part numbers like 06A 906 018 FB


Is there a difference with the ones with cruise (besides having cruise)? I like my cruise


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## scotty_passat (Apr 17, 2001)

*Re: Decode Secondary Air Injection Pump in your 2.0 (elRey)*

ok, that must be different than the 1.8T, or I'm mixing it up with one of the other systems...

_Quote, originally posted by *elRey* »_
I've been studying wiring diagrams for AZG and AWP for months now.
I have the wiring diagrams up now, and no pressure switch or extra wires
to the pump that would facilitate any kind of sensor/switch in the pump
itself. There's no mention of a pressure switch for SAI system either.
Rey

_Modified by elRey at 6:46 AM 5-3-2006_


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## randallhb (Sep 17, 2002)

*Re: (v-tecs suck)*


_Quote, originally posted by *v-tecs suck* »_Isnt there a way to just tranfer the data from one of those ecus to yours????

It is possible to transfer the program from one ecu to the other, that it later works is totally different. This has been done in tdiclub to install european programs in their cars. It is sort like chipping but with a stock program.


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## SLVR SLUG (Dec 10, 2006)

*Re: (randallhb)*

has anyone come close to a soloution for the mkIV? cuz id sure like to get rid of that stupid CEL


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## 21tuningolf (Dec 29, 2007)

i'v been going thru the same thing with my golf since i put headers on a couple of years ago. been living with cel for a while now, i'm going to try the coding at my freinds audi dealership. thanks for the info tdogg74 i'll let you know how it goes.


_Modified by 21tuningolf at 4:27 PM 1-6-2008_


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## tdogg74 (Mar 1, 2002)

*Re: (21tuningolf)*

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


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## ejg3855 (Sep 23, 2004)

*Re: (BlUnT MeKaNiX)*


_Quote, originally posted by *BlUnT MeKaNiX* »_has anyone come close to a soloution for the mkIV? cuz id sure like to get rid of that stupid CEL

You need to get a ECU that doesnt have one and have that code copied over to yours.


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## SLVR SLUG (Dec 10, 2006)

if im not mistaken they only came on the DBC cars. and mine is a GAY DBW. so i dunno how well that would work. but if u have done it. or know someone who has. please let me know.


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## pwnt by pat (Oct 21, 2005)

*Re: (BlUnT MeKaNiX)*

If I'm not mistaken, parts of the ecu code can be re-written over, such as the SAI code. Ask C2? They should be getting a non-SAI ecu soon IIRC.


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## 21tuningolf (Dec 29, 2007)

*Re: (tdogg74)*

bump for awesome info http://****************.com/smile/emthup.gif


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## volkyland (Jul 24, 2000)

I have a question? I have a 1998 New Beetle 2.0L. The secondary air pump now stays on running 24/7, even with the engine off, and ignition off. Any suggestions what is keeping the pump running 24/7? any relays, etc etc?


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## 21tuningolf (Dec 29, 2007)

there should be a relay in the engine bay.


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## KelvinQ (May 1, 2005)

*Re: Decode Secondary Air Injection Pump in your 2.0 (tdogg74)*

What does it exacly do to your ecu apart fom that, does it make your ecu think its an OB 1. or keeps your ecu the same and just delets the air pump.
Am wonering cause am planning to get a BBM supercharger and not sure whether to get an OB 1 chip or an OB 2 chip. someone please let me know


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## 97VWJett (May 17, 2003)

*Re: Decode Secondary Air Injection Pump in your 2.0 (KelvinQ)*

You have an OBD2 car. Anything before December of 1995 is OBD1. Anything after January 1996 is OBD2, supposedly.
This trick changes the fuel mapping and timing curve, from what I have heard. If you have a manual, change it to an automatic. People have claimed a big noticeable change.


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## themagellan (Mar 30, 2007)

hey travis... i'm in cali... its dope out here anyway dude...
if i turn this off do you think that will make me be able to run this q-chip without the cel coming on for the secondary air bump

thanks dude!


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## tdogg74 (Mar 1, 2002)

when you decode this, its just like the ECU doesnt even know its there. The chip you run shouldnt have anything to do with the SAI at all.
BTW, how are you and your hottie girlfriend enjoying Cali? Any luck with the job market?


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## themagellan (Mar 30, 2007)

well mines a 96 and i have a obd2 chip, but it expects a air pump, but alas doesnt have one.

we're awesome its so nice our here. Miss all you guys though.
what job market i'm enjoying it for a week or two before i become a slave again


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## 21tuningolf (Dec 29, 2007)

*Re: (tdogg74)*

i finally decoded the ecu and removed the relay and got a cel for incorrect voltage.should i still keep the relay and fuse hooked up?


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## _pineapplegti_ (Apr 26, 2006)

*Re: (randallhb)*

bump


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## _pineapplegti_ (Apr 26, 2006)

*Re: Decode Secondary Air Injection Pump in your 2.0 (tdogg74)*

Update.. the auto code does not make your car any quicker.. i did 10 back to back tests 5 as the car coded as a manual 5 car coded as a auto. I had the same quatermile time and same 0-60 time per vagcom.. It was kinda fun to do it though


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## SLVR SLUG (Dec 10, 2006)

*Re: (randallhb)*


_Quote, originally posted by *randallhb* »_Just get another ECU, immobilizer II ECUs take no more than a seconds to adapt using vag com.


have you done this? and they will work with all mk4's


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## jupiters_spot (May 4, 2012)

*What book is that scan from?*

My Bentley (Volkswagen Jetta, Golf, GTI, Cabrio Service Manual 1993 throuh 1999) has no section 25. What book did you scan this page from? I need to find a copy.


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## zero. (Aug 14, 2001)

Don't have it in front of me, but I'm pretty sure it's just one of those sections towards the front of the manual with the general maintenance info. Should be an entire section on scan tools and control module coding. The section is actually ST (Scan Tool). 25 is the page of the section.


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