jav

A friend of mine offered me his second ECU and performance chip from his '01 S4. First question obviously is whether or not it will fit/work/be compatible with my '02 allroad 2.7T. The second question is where the model number for my ECU can be found. Do I need to crack open the box or can I simply pull the cover off the weather-prrof box and read the model number? Lastly, do the model numbers need to match exactly, or is there some variance that will still work properly?

Thanks in advance.

paulroad

1. Use a VAG com and scan the engine. The ECU # will be shown.

2. Open the black ECU box, the BOSCH Label is on the metal case of the ECU.

The ECU from the S4 will fit, but...know one has said foer certain if it will work. Every CHIP guy I spoke to during my research said they are virually the same, but there are different "fuel maps" used in different cars..subtle upgrades...

A good Example: My ECU is: 4Z7907551-S, when the recall service was done, it was re flashed by Audi and now reads with a vag 4Z7907551-R

Another concern would be your immobilizer.. you will need to get the codes (SKC) from your dealer for your car. If its a 7 digit code and the S4 is based on a 4 digit then you are SOL.

jav

So, if I have a different length security code, the imobilizer won't work, or the car?

paulroad

yup.