Replaced ABS module. Now says "defective" and "incorrectly coded"
 

Hi there

I've had an issue with this for the longest time. I've replaced it once before but could never get it working properly, even after repairing it. Then I bought another used one and it says "control module defective" and "incorrectly coded". It won't accept my coding "0007597".

At least the brake pressure sensor fault is gone. But does it not accept my coding because of the defective code? Or maybe it needs the coding of the previous car it sat in? Is it automatically toast if I get the defective code?

I can't keep buying used ones, which costs a lot of money, if they won't work

Audi A8 2003 4.2

I've now managed to get it to accept my coding. Had to login using Coding 2 and then enter my coding. I then delete the codes and only the defective code returns. But as soon as I exit the module in VCDS and then connect to it again, the coding is lost :Confused: I've tried doing the steering angle calibration but it won't let me.

Sounds like the internal memory has failed which is also why the coding won't stick.

Maybe try talking to our sponsors to see if they have a known good unit in stock?

Bit of a wild guess here. I'm assuming there is an option to do this, and you have saved the code once you have entered it?
I had a similar issue with VCDS not remembering the new code that I was entering, and then I realised that I had not been hitting the 'save code' button before exiting.

Once I enter the code it says "Code accepted" and I click OK. Then it returns to the ABS module main screen. The coding is still there. Then I click "Done" and it goes back to all the modules. There is no other save button

Well, I managed to get the coding to stick and successfully calibrated the steering angle sensor. I used the wrong login for the basic settings. The warning lights have disappeared and the only code left is the defective one. I'm cool with that as long as the warning lights stay away. Time will tell

I think once the 'control unit defective' shows up it will always remain there, even if it is working properly