Audi A3 TDI: Location of Engine Control Unit (ECU)

'In my Audi, the engine shuts off after just 2 kilometers (see my post from yesterday).'

I've now resoldered relay 109, and the error hasn't reappeared yet, but it doesn't necessarily mean anything.

On that occasion, I looked for the engine control unit but couldn't find it.

Where is it?

Could the MSG (Main System Ground) be located under the battery? There's a thick cable bundle running to that area.

It would be a great spot, but if battery acid leaks out, the entire system is immediately compromised.

Or am I wrong?

Hi,

The control unit will likely be located, as usual, next to the windshield wiper motor inside the water reservoir. Remove the covers and you'll see...

Best regards, Andy.

Quote:

Where is that thing?

Hi,

Located in the water reservoir, centered under the plastic cover. Unfortunately, to access it, the windshield wipers must be removed and the wiper mechanism disassembled.

Best regards, Rainer.

Thank you!

Yes, when I was wiring the cruise control system, I had to remove the windshield wiper motor as well.

I hope I don't have to deal with that thing.