ACE 16v ECU swap

Posted: Mon Dec 11, 2017 2:59 pm

Hi, I have a b4 with and ACE 16v engine with an immobiliser. Can I swap ECUs from a donor car or is there an immo delete or Ross tech procedure to marry the new ecu?

Site Moderator Joined: Jan 31, 2003 Posts: 9144

Not sure if a non immob ecu would work straight out the box - might be worth a try.

Only other option is to get it bypassed

Posted: Thu Dec 21, 2017 10:21 pm

I’m going to crack open the ecu case and check for dry solders under the microscope.

I read somewhere about the immo delete, I guess that could be applied to the replacement ecu.

Posted: Mon Jan 08, 2018 10:31 am

Did you manage to do an immobiliser bypass Eightyway and if so how did you go about it using Vagcom / VCDS?

Posted: Mon Jan 08, 2018 11:44 am

Actually, the ECU seems fine. I resoldered every connection which took a while. I got the car running this weekend!

Confirmed the Cold start valve and injectors working.
Removed air filter, and heater bypass valve

The car ran but could cut out easily - like releasing the throttle suddenly or even using the power steering! The car was hunting at idle.

I did a hack fix by adjusting the fuel mixture out of spec (triggering a 00533 idle code) but the idle was then solid at 1000rpm. I believe this forces the ISV open. The downside is that it is spitting out plenty of carbon deposits.

I have yet to puzzle out exactly what this all means. I need to go back to my research on the Motronic, however I believe I need to look at the sensors that regulate the ISV. Thinking of these off the top of my head:

- TPS position
- Air flap potentiometer
- Differential pressure regulator
- Lambda sensor

Posted: Tue Jan 09, 2018 10:23 am

sounds like you are making progress, hopefully you get it figured out soon.