Headlights gone crazy

[Fast4esT]

With car off and key not in ignition, the high beams turn on, if I push the high beam stalk forward to "on" they turn off. With the headlights on I can not turn the high beams off.
They are Depo/TRS bizenon

Is it one of the two headlight switches?

Flash to pass works but it turns the highs off until I release it.

[Seerlah]

How long has this been going on for? If this happened with new headlight assembly I would say it is a DEPO headlamp issue with polarity being the issue. If it just happened out of the blue, then I would say stalk issue. I don't know the B6 headlamp wiring, but if this happened because of the former I would mess with the headlamp wiring. Hopefully a simple thing like swapping two wires for the high beams will fix it (reversing polarity), if that is the case. Once again, that is just a guess fix because I don't know the wiring. Could be something else like an internal relay that needs the NO/NC wires swapped off terminals. I would wait for confirmation first or check yourself is this is a feasible path. Don't want you to ruin something on your vehicle to my guess for a correct fix.

[Fast4esT]

Happened out of the blue, headlights installed 3 years ago, never an issue. I did park next to a sprinkler with my window open over night, sprinkler was on a timer, sprayed inside the car a little, was totally dry when I got in this morning, exterior is all spotty from water, t shirt on the seat was damp but all else dry. The plenum under the battery is dry. I'm wondering now if water could have gotten into the steering column and caused a short or the CECM is failing on me.
High beams should not have any power when car is off, high beam switched to off position and the lights come on, switch high beams to on position and they turn off. This is with no key in ignition.
Not much coming up from a search aside that the cecm can have many different symptoms of failure and randomly too.

[Seerlah]

I don't have a B6, so I don't know how your wiring is (just recalled the dial you guys have). I would just take out the stalk and switches then clean the contact points (inspect same time). Afterwards, spray with electric parts cleaner. Spray that on all related electrical components too. Fuses pulled or negative battery terminal removed for safety reasons. Sounds like a relay issue to me. Follow switch wires to the relay it goes to and inspect that. Basically it is looking like NO is now NC and vice versa.

[Fast4esT]

From what I've read, there are no relays for the headlights. I will inspect and clean contact points

[diagnosticator]

It is very possible that the CECM has failed. This module powers all of the exterior lighting, and switches the lamp circuits ON and OFF, using solid state transistor switches inside the module. When the CECM fails, every individual case is a unique set of malfunctions with the lighting. If you have VCDS, scan the 09 Central Electric module for fault codes. Please post back the results of the scan.

[Fast4esT]

I scanned it with shade tree pro diag

09 electronic ctrl. Electronics
01331177 door driver side- no communication

Only fault under 09

Also scanned
46 Conven. Sys. Central module

VW-Group convenience data bus: in single wire mode
Rear door left does not disengage
Rear door right does not disengage
Driver door control module in single wire mode (sporadic)
Alarm horn h12 no communication

I have a new wire harness for driver door I need to put in, it randomly looses power when it's shut, assume broken wire. Easier to swap it all out than repair a wire

Nothing exactly pertaining to headlights or CECM

This evening while driving it went back to normal, everything working correctly. Except the flash to pass does nothing now.

[Seerlah]

I have a new wire harness for driver door I need to put in, it randomly looses power when it's shut, assume broken wire. Easier to swap it all out than repair a wire

Actually easier to repair broken wire, but you already have the replacement harness. Shorts are most times exposed on the harness and not wrapped under the cloth tape. Easier to find it (area to search narrowed down to only exposed sections), cut for clean wire, butt connect, done. Did this to a short on the harness behind my door card little while back. Not sure if it was a problematic short, but would have been. It was exposed with green on it.

[Fast4esT]

It's been repaired before, thought this time replace it. Hardest part is getting the plug boot back on

[diagnosticator]

One of the DTCs states "single wire mode". This means that the CAN buss for that group has one of the two CAN wires disconnected somewhere. CAN buss networks are controllers connected together by a twisted pair of buss wires. CAN High, and CAN Low. There are three separate CAN buses employed on our B6 A4s. There is the Power train CAN, The Comfort Convenience CAN and the Infotainment CAN buss. All three CAN buses are connected together by the CAN gateway in the instrument cluster. Two Low speed CAN buses, Infotainment and Comfort, run at 100 Baud, the Power train CAN runs at 500 Baud. The DTC says the Comfort CAN is in single wire mode, with one of the two CAN buss wires, CAN high or CAN low, open circuit.

[Fast4esT]

Two of them did,
Driver door and ...

01336 208 VW-Group convenience data bus: in single wire mode (sporadic)

That's a weird one, also there where no P codes or are those just engine related?


Would that explain why it took differant baud speeds to connect the scan tool?

I'm way under paid for this, how do I understand what I am looking for or find the fault?

Thanks for your responses by the way;)

Forrest

[Fast4esT]

Does a high or low can buss wire pass through the driver door?

If this helps at all, the passanger front door does not trigger the interior/puddle lights when opened and the car is running, but it does work normal when car is off. Rear passanger door is completely sporadic. The rear driver rear door has never had any problems but for last 4 years has thrown a DTC for not disengaging.

The driver door DTC is a new one, Twoweeks ago the door window switch lights would lose power, speaker would cut out and window would stop working, also the red light on the door will flash when when the door loses power. This is why I picked up a driver door harness.
When I would open the door, everything would go back to normal.

Also yesterday morning when the high beam problem started, the lights where not on when I walked to the car, I'm pretty positive they turned on when I opened the driver door.

[EuroxS4]

If the comfort module says it in single wire mode.I would be pulling the carpet and looking for water.9 times out of 10 water gets in fries the comfort module.Most likely cause of water intrusion is clogged sunroof drains.Or a broken ebox cover on the drivers side under the hood after some hack installed a boost gauge and broke the cover when removing it because he didnt realize there was a bolt under the drivers side wiper.

[Fast4esT]

Haven't had a leak in years, carpet dry, but maybe past damage is now surfacing?
Had interior door codes I always thought where door lock switches, but I don't think that's it anymore. I'll pull the ccm out and inspect it.

Thoughts on the CECM?

[diagnosticator]

Does a high or low can buss wire pass through the driver door?

If this helps at all, the passanger front door does not trigger the interior/puddle lights when opened and the car is running, but it does work normal when car is off. Rear passanger door is completely sporadic. The rear driver rear door has never had any problems but for last 4 years has thrown a DTC for not disengaging.

The driver door DTC is a new one, Twoweeks ago the door window switch lights would lose power, speaker would cut out and window would stop working, also the red light on the door will flash when when the door loses power. This is why I picked up a driver door harness.
When I would open the door, everything would go back to normal.

Also yesterday morning when the high beam problem started, the lights where not on when I walked to the car, I'm pretty positive they turned on when I opened the driver door.

Yes, there is a Comfort CAN buss between the door control module and the Comfort module under the driver's carpet.

[diagnosticator]

Two of them did,
Driver door and ...

01336 208 VW-Group convenience data bus: in single wire mode (sporadic)

That's a weird one, also there where no P codes or are those just engine related?


Would that explain why it took differant baud speeds to connect the scan tool?

I'm way under paid for this, how do I understand what I am looking for or find the fault?

Thanks for your responses by the way;)

Forrest

Audi/VW has an SSP describing the CAN buss networks functional aspects and troubleshooting procedures. It is out on the net somewhere I don't know the SSP number off hand.