Audi A3 BKD 2007 non start, flashing brake warning and no ECU communication

[Crasher]

Remind me tomorrow, I did write a long reply to this but it looks like I did not send it, probable got dragged off to do some real work.

[rocktheboat]

will do - I appreciate your help with this.

[Crasher]

If you have no power from the relay, jump pins 1/30-2/87 so as to directly power the ECU. If this makes it start then change the relay.

[rocktheboat]

I must have power going between 1 and 2 as the fan works until I take the relay out. I did jump 1 and 2 to test and now change.

However I have 12v @ pin 5,4 and 2. Don’t seem to have anything at 1 ( although the fan starts running straight away until the relay is pulled )

[Crasher]

We need to step back a circuit

[rocktheboat]

Ok -where now

[Crasher]

Tomorrow

[rocktheboat]

Ok

[Crasher]

You are going to have to take off the ECU chastity bracket and unplug it so you can test the feed to the ECU plugs pins.

[rocktheboat]

Okay, and what pins please mate. I’ll take off tomorrow night