A3 1.8T Sport cutting out and dipping lights

[jayA3]

Hi, I bought a 2001 Audi A3 1.8T Sport a few weeks ago, the EPC light was on, but it drove spot on when I took it for a long test drive, so took the risk.

A few days after I got it I pulled up to traffic lights and the warning light flashed (also ESP and EPC) and the engine, stereo and heating cut out. It started again first time and no more problems. It did this another couple of times that week. Also on a couple of occasions the central locking decided to stop working for a minute or 2.

I got the diagnostics done and the fault showed up as 17072 - ECM Power Relay Circuit: (J271): Open Circuit. This was cleared. The guy in the garage then stalled the car to see if it would bring up an error code, all lights on the dash faded away and then the car wouldnt start. Battery and alternator were both fine. The car then decided to start, but no error code. The guy said to go back if EPC light came on again.

No problems for a week or two after that. Yesterday took it on a long drive, no problems in the light. Came back to car in the dark and had the interior light on for a bit without engine running, started it and then it cut out (ESP light flashed on). Again started first time after that.Driving back in the dark I noticed that whenever I lifted from accelerator to the brake, the headlights dipped (didnt happen just when lifting from accel). Stopped at services and realised that they also dip when turning on stereo or rear screen heater. Also interior light is dull when engine is not running (though this may be normal?).

The EPC light remains off, but somehing is definately up. It drives amazingly when its having a good day, but I want it 100%! Has anybody got any ideas?

Sorry for the long post but thought I would give as much detail as poss!

Cheers

J