Passenger Front Parking Light wont turn off, Flickering Tail Light, No interior light

[MurkyRivers_A4]

So yesterday we had a pretty decent amount of rain come down all at once. This has happened before and had never caused any issues with car, until yesterday.

After work, I got in, like I normally do, and started her up. I get a warning on the DIS letting me know the front right turn signal is out then immediately after the rear right light is out as well. Kinda fishy but ok, no biggie maybe I just need new bulbs.

So my friend is driving behind me and lets me know that the rear right light is flickering off and on. Weird again but maybe just the bulb. So I get home and shut the car off. Walk around the front and the right front turn signal is illuminated. I take the bulbs out and they are both fine. I pull the front right head light out and cant find any issues with the light housing or the wire harness.

So I do some Googling and hit up some fellow enthusiasts. Check all fuses and they are fine, triple checked that I didnt accidentally leave the turn signal stock in the up position. Then notice that none of the interior overhead lights work, including vanity mirrors. So I try the sunroof and sure enough that also isnt working.

Im at a loss and can only think that MAYBE the Central Electronics Control Module is at fault?

Any ideas?

[walky_talky20]

It sounds plausible that you have a water ingress issue that has caused some problems for the CCM. I would check the usual spots - see if the ECU box is full of water, and check for moisture under the carpet on at least the driver's side.

[MurkyRivers_A4]

It sounds plausible that you have a water ingress issue that has caused some problems for the CCM. I would check the usual spots - see if the ECU box is full of water, and check for moisture under the carpet on at least the driver's side.

I do know that the ECU plastic cover is cracked so its very likely that water has made its way in. I will check that today to be sure.

Do you know the location of the CCM? I cannot pin point it and am just getting general locations but they seem to be all over.

[Let it snow]

I do know that the ECU plastic cover is cracked so its very likely that water has made its way in. I will check that today to be sure.

Do you know the location of the CCM? I cannot pin point it and am just getting general locations but they seem to be all over.

The module that controls the lights is below the ECU. If you remove the panels above the pedals it is on the left, roughly a little below light switch height if i recall. Sorry no pictures. Something similar happened to a friend of mine. Module got wet from a bad windshield replacement job. Side marker lights would not shutoff. Module was bad and it also melted the ground wire going to the module. Good luck.

[Let it snow]

I just realized that module could be just half your problem. The one just below the ecu controls all exterior lights. You also mentioned your interior lights not working. That is controlled by the CCM on the front drivers side floor under the carpet next to the door trim. Hopefully that also did not get wet.

[MurkyRivers_A4]

Just checked the ecu box and its completely dry. Ill have the check the modules at lunch.

Occasionally I can hear water sloshing back and forth in the car. Hoping its nothing.

[Willënskraft]

Is the battery ok'?

[MurkyRivers_A4]

Is the battery ok'?

Yup, battery is 12.4 volts.

[MurkyRivers_A4]

On my lunch I have checked both modules located under the drivers side carpet as well as behind the fusebox. Both seem completely fine and dry. There is no built up water or anything of that sort under the carpet, on the carpet or in or around the modules.

I did open up the box for the control module under the carpet and unplugged everything. That did not stop the front turn signal from staying illuminated and it did not allow the interior lights to come on.

After putting everything together, I noticed that key fob is no longer working, which it did just fine before I went to lunch. Perhaps I have to reprogram the FOB after having disconnected the module?

Any other thoughts or possibilities for this crazy issue Im having with the lights?

[Let it snow]

All of the exterior lights including the windshield wiper and horn are controlled by the VECM under the dash. I suspect the exterior light malfunction is due a to a problem with this module.

[MurkyRivers_A4]

Horn and windshield wipers are functioning normally without issue.

Where is the VECM located?

[Let it snow]

Take it out and look at the board for any burning or corrosion.

[MurkyRivers_A4]

Take it out and look at the board for any burning or corrosion.

That is the one that I looked at. Although I didnt remove it and open it up. I will do that today.

Would you happen to know where the harness for the front right headlight connects to? I am getting a second 12v wire when there should only be one. I cant imagin the harness itself being bad but perhaps wherever it connects to?

[Let it snow]

The positive + runs directly back to the VECM for each individual light.

http://www.bentleypublishers.com/ima...i.b6.wd.02.pdf

The water you here sloshing may be under your battery in the tray. Take a look there for standing water. Good luck.

http://www.audizine.com/forum/showth...r-water-drains

[old guy]

Just checked the ecu box and its completely dry. Ill have the check the modules at lunch.

Occasionally I can hear water sloshing back and forth in the car. Hoping its nothing.

That is definitely not good.

The positive + runs directly back to the VECM for each individual light.

http://www.bentleypublishers.com/ima...i.b6.wd.02.pdf

The water you hear sloshing may be under your battery in the tray. Take a look there for standing water. Good luck.

http://www.audizine.com/forum/showth...r-water-drains

It's not the drain under the battery tray. It's the drain underneath the brake booster causing your problem. when that drain clogs water will run underneath the dash and drop directly on the VECM.

[MurkyRivers_A4]

So I unplugged the VECM and sure enough the light went out. Makes sense considering its controlled by the VECM. So I decided to take it apart.

Nothing looks to be out of the ordinary.

[MurkyRivers_A4]

Just to be sure Im on the right part

[Willënskraft]

Hmm any rust or moisture on the connectors/plugs maybe?

Also, like old guy said about the drains, try checking and see if it's clogged.

[MurkyRivers_A4]

Hmm any rust or moisture on the connectors/plugs maybe?

Not at all. The pins and connectors are perfectly fine and clean. This is driving me nuts.

[MurkyRivers_A4]

Status update:

Car is still trippin' and keeping that front right parking light on. I probed the right headlight connector and am getting 2 pins with 12v with Key Off where the left side only has one wire with 12V constant.

The two wires with 12V on the right side harness have been probed and do have continuity, which is a bad thing.

So I unplugged the harness from the passenger foot well, where the headlight harness connects to, and probed the wires again and this time they did not have continuity. Thats a good thing and means the headlight harness itself is perfectly fine.

So I then plugged it back in then unplugged the from the VECM. Went back to the front and probed the wires and this time I am getting continuity again. So this is a good and bad thing. Good because it means that the VECM is fine and bad because it means somewhere between where the headlight harness plugs into the passenger footwell, and where the harness connects to the VECM, I have bare wires making out with each other.

[MurkyRivers_A4]

Status Update:

After tearing apart the dash trying to find the faulty wires or short that was causing this problem, I wasnt able to find anything wrong.

I called up my buddy and asked if I can try installing my module in his car to see if the module was the issue. He gave me the green light so I headed over and swapped his for mine. Sure enough, the damn VECM (or whatever its called) was the issue.

Physically looking at the board I could not find a single issue with it. So let this be a lesson, just because it "looks" good doesnt mean that it is.

Thanks all for the help and advise and especially to OG and Let It Snow for giving advice.

Problem Solved/Case Closed...... for now.

[diagnosticator]

The CCM/VECM has a history of arbitrary random failures. When this happens the symptoms are unique to each failed module. Since the corner lamp/turn signal is ON with the wiring connected to the module, that is practically 100 percent caused by a faulty module.

The remote locking fob quit working because you disconnected the wiring from the comfort module under the carpet. To re initialize, insert the ign key in the ign switch, turn the ign switch to ON but do not start the engine. With the ign ON, press one or two buttons on the remote then turn the ign OFF and remove the key. Exit the car then test the remote locking function.

[MurkyRivers_A4]

The CCM/VECM has a history of arbitrary random failures. When this happens the symptoms are unique to each failed module. Since the corner lamp/turn signal is ON with the wiring connected to the module, that is practically 100 percent caused by a faulty module.

The remote locking fob quit working because you disconnected the wiring from the comfort module under the carpet. To re initialize, insert the ign key in the ign switch, turn the ign switch to ON but do not start the engine. With the ign ON, press one or two buttons on the remote then turn the ign OFF and remove the key. Exit the car then test the remote locking function.

Thanks, I figured the key fob problem out shortly after I screwed it up lol.

At least now, if someone has the same issue in the future, this thread will help.