Hi fellas. My current ECU is toast and looking for a replacement. My 98 1.8t manual quattro came with 8D0 907 557 T ECU. Will a 8D0 907 558 M work? What does the letter mean anyway? TIA

 

What happened to your current ECU?

As far as I know you can't just take an ECU from one car and plug it into another car. But I believe as long as it gets programmed to your car it should work. Not sure what the numbers mean.

 

I have never seen nor heard of a 557T ECU in North America, are you in a non North American country? A quick search leads me to believe that the 557T ECU has an immobilizer, North American B5s do not have an immobilizer.

I personally know that 558M, 557P, and 557N ECUs for an AEB (nDBC) are interchangeable.

557P should be able to switch between automatic and manual transmission, I believe 557N is locked to whatever drivetrain it came with from the factory.

 

Yes very true. I have an immobilizer. I now live in the Philippines, so i believe i have a euro b5. Now do you guys think the swap will work? Only reason i wanna switch my ecu because it currently has a code 16989 - Internal Control Module P0605 35-00 Rom error. From searching all over google it seems like im currently running with a bad ecu and needs to be replaced unless someone knows a way to fix the code.

 

Does the car still run fine? Shoot a message to k0mpressed on Audizine or Reflect Tuning, they should be able to point you in the right direction for that code and/or a replacement ECU/tune.

If the car/instrument cluster is set up for an immobilizer, you cannot switch to an ECU without an immobilizer. 558M does not have an immobilizer and would be a no-go.

 

It would still work, you'll just have a constant immo light. The immo unit in the cluster can't shut down the motor if the ECU doesn't have any immo software/hardware.

 

Good to know, thanks for the correction. Immobilizers aren't my specialty since I've never had to deal with them.

 

I really appreciate all your guys' thoughts. Car runs fine with code. I guess having the immo light on will annoy me more than a fault code. Maybe i should look into bypassing immobilizers before taking the chance on a different ecu. Thanks again everyone.

 

My 01J927156FF rectangle plug just fried as well for 02 A4 1.8T CVT, looking at getting a 01J 927 156 OJ. As long as it is a 01J can I use it and just refresh it if necessary or will it just plug and play with an immobilizer like the other individual was asking?