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Audi R8 V10 Coupe 2010 R-Tronic
14 Posts
Discussion Starter · #1 ·
A new problem cropped up in the R8 this week. It started with a CEL that kept coming back with the same fault of ECU checksum error on Bank 2 and threw random O2 sensor faults and lean mixture codes while Bank 1 ECU remained faultless apart from a message saying check ECU 2 DTC.




I thought I'd disconnect the battery after the fault code reset and upon reconnecting the battery, the car would crank and run poorly and sputter and it sounded like it was running on one side of the engine.

Pulled the codes and now it shows from Engine 1 that it has trouble communicating with the Slave ECU and showed another fault for ECU Pin.



I'm still able to access and diagnose the Slave ECU (Bank 2) and it also shows the ECU pin error apart from CAN communication error codes. I also noticed that the throttle bodies no longer hum and click when I turn the key to position 2.




Does this indicate a problem with the Bank 2 (Slave) ECU or something else along the line? I tried disconnecting and removing the ECU and checking the connectors but all seemed fine. I'm actually angry with myself for trying the battery disconnect as I was still able to drive the car earlier today without issues apart from the recurring CEL.

Also to my knowledge the car has never been remapped.

Any feedback and insight would be much appreciated. Thank you so much!

7 Posts
The checksum error is something I would usually associate with a tuned ECU or possibly one with issues internally. If you are reasonably confident the car has never been tuned you could try having the ECU's reflashed with the same factory software version. There are a number of after market tools that can do this now and some do not require the ECU to be removed from the car to do this. The bigger name European tuning tools now offer a "Bench Flash" method that just connects to the wiring pins direct on the ECU and no longer requires the lid to be removed.

Another alternative is to have the car updated by someone with the right access to ODIS which is the official Audi dealer workshop tool. This won't work if there is no update from Audi so the aftermarket route with a good tuning shop is more likely to be the way to go.

It would also be a good idea to check the ECU's physically to see if there is any witness marks from them being opened for reading & programming in the past. For a very, very long time you had to open the ECU's to tune these cars so it may have been read, tuned and flashed back to stock at some point in the past. If you are not the original owner you never know for sure.
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