View Full Version : ECU Headaches

11-09-2014, 10:15 AM
I had posted this on other forums but it quickly got buried.

This seems to be a great community so thank you for any insight.[wrench]
2001 Audi A4 v6 Manual Trans

A few months ago I had parked my Audi so that I could continue to work on it while not driving it daily. I put my 337 on the road and had unexpected bills.

As my car sat I would try to start it and let it run about every other day. I will give some background on the car.

I had a few of the common Catalytic converter codes but when I went to scan it most recently after the battery had died, it had an ECM Fault code. P0604 Internal Control Module Random Access Memory (RAM) Error

The car became hard to start.

The CEL would not illuminate with the KEY ON. Understanding there was something screwy with the ECM, I unplugged it and Plugged it back in. The CEL came on and i knew there was a good sign the car would start and it did.
I had continued this habit of unplugging the ECM just to get the car to start and run for a while but I can finally start working on the car and I would like some advice.

Just recently I had sent out the ECM to be repaired. This was fairly inexpensive and I was sure this would work. I received a call saying that the ECM was all fixed and the Processor was damaged.

I reinstalled the ECM and was happy to see the CEL turn on with the Key On.

The Engine fired right up and ran for a few seconds before sputtering and dying out.

Upon trying to start it again there was no CEL and it just kept cranking.

I searched and found there was coolant migration issues with these cars and am not finding any under the Coolant Expansion Tank at the connector.
Are there any other areas I should search for Common electrical issues?

Some other Electrical related Issues
Coolant Temp Gauge is sporadic and displays incorrect or no temp at all
OIL Temp Gauge is sporadic and displays incorrect or no temp at all
Fuel Gauge does not work (May be fuel pump potentiometer wire)

I would be so grateful for any information.

Thanks so much, Peace