ECM differences AHU?

thesimpledog

Member
Joined
Sep 12, 2011
Location
Clarksville
TDI
just an AHU motor
Hello, been wandering thru the "search" function and cant find my answer. I got the chance to pull a 1.9TDI from a 97 Passat, was not able to get harness or ECU/ECM. Actually I cut harness right behind gray connector and left pigtails. I want to swap this into a custom chassis rock crawler.

My question is: Can I use any ECM from a AHU to ALH motors, considering I wont be using cluster/accessory functions? AND I will be sending it to RC to be worked up.


Kinda a bunch to ask for a first post, but at least I tried to get my stuff together.
 

mogly

Veteran Member
Joined
May 27, 2003
Location
Sarnia, ON, Canada
TDI
MKIV TDI + B5.5V AVF/01E
Typically the AHUs had the JB coded ECMs. GQ will work but aren't as common. BK will also work but are pretty limited with chipping.
 

Lug_Nut

TDIClub Enthusiast, Pre-Forum Veteran Member
Joined
Jun 20, 1998
Location
Sterling, Massachusetts. USA
TDI
idi: 1988 Bolens DGT1700H
1Z and AHU ECU's were 68 pin. ALH I believe are 120 pin.
The ALH 120 pin ECU may be looking for inputs that the 1Z/AHU engine doesn't have.
The 68 pin has no EGR feedback loop, wastegate controlled boost limit. The 120 pin has EGR feedback and a push-pull control for the variable nozzle geometry turbo.
For the best opportunity I'd suggest staying with the 68 pin ECU with your AHU engine.
 

Lug_Nut

TDIClub Enthusiast, Pre-Forum Veteran Member
Joined
Jun 20, 1998
Location
Sterling, Massachusetts. USA
TDI
idi: 1988 Bolens DGT1700H
1Z and AHU ECU's were 68 pin. ALH I believe are 120 pin.
The ALH 120 pin ECU may be looking for inputs that the 1Z/AHU engine doesn't have.
The 68 pin has no EGR feedback loop, wastegate controlled boost limit. The 120 pin has EGR feedback and a push-pull control for the variable nozzle geometry turbo.
For the best opportunity I'd suggest staying with the 68 pin ECU with your AHU engine.
 

thesimpledog

Member
Joined
Sep 12, 2011
Location
Clarksville
TDI
just an AHU motor
Guys thank you for the info. If I were to attempt to use the ALH or 168 pin computer....wouldnt the vagcom be able to kill the other functions of pins?
 

JoaoT4

Veteran Member
Joined
Feb 20, 2010
Location
Portugal
TDI
Eurovan Conversion
No.
The software on the ALH is more complex and need more inputs that you can't delete. The VSS is mandatory on the ALH, but it is only necessary on the 1Z/AHU if you want a cruise control. This is only an example.
If you want to transform an ALH ECU on a 1Z/AHU ECU then buy the last one.

João
 
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