Need Help Diagnosing a weird electrical problem

04S80Christene · Post by **04S80Christene** » 10 Oct 2018, 16:14

I have an 04 T6 that’s having issues. The other day I had the lights in my instrument cluster go off while driving. Gauges still worked but lights went out. Had the head lights on but upon turning them off they started to flicker on and off. This persists at random but funstions normally when the headlights are on. On top of this issue the airbag service warning randomly came on.

The only changes I have made recently is the replacement of a broken headlight with a used OEN unit which functions perfectly. It took about a week after the headlight for this problem to present itself.

Has anyone experienced this problem before and if so any ideas on how to fix it?

Post by **SuperHerman** » 12 Oct 2018, 21:55

You may have a CEM issue. Usually this is caused by water intrusion. Has the car been in the wash or rain recently? You should make sure your sunroof drains are clear and the drains at the corners of hood closest to the window don't have leaves and related.

Do some searching on CEM removal and check the area for signs of water getting in there. For starters just get to the unit and do some looking - no need to remove it. If you decide to pull it out - disconnect the battery negative lead first. Sometimes the CEM will dry out and cause no further issues. But if it looks like it got wet it would be worth pulling the unit and cleaning all the connectors, relays and shunts (one at a time).

That is where I would start. If all looks fine and the drains are flowing free it may be another issue.

MIB · Post by **MIB** » 24 Nov 2018, 01:46

I had the same problem with the instrument cluster in combination with a non-functional head light and fog light.
I turned out to be the light switch that caused these problem.