CCM acting up - no door locks, no power windows etc

Searching through the other threads, there are some that are close, but not exact.

Driver's door ajar warning came on in the MFD last weekend, and would not go out whether the door was open or closed. I have replaced the door latch with ($$) VW about two years ago.

Light went away and all was normal for a week, until this morning.

Same thing happened, opened and closed the drivers door, and then it went away.

Drove to work and then the alarm would not set. fob stopped working altogether. driving home, the locks are still inoperative, and now the power windows are not working.

Got home, noticed a wet CCM under the drivers carpet is common, so pulled the seat and carpet and found a bunch of water. Sopped that up and checked the CCM - dry (whew). CCM ground looked very crusty thanks to the moisture, but the 10mm off showed the ground to be clean - backed up by DVOM.

Currently have a space heater drying everything out, and have checked the sunroof drains (clear, no trees in my parking areas), everything is still inoperative.

One weird behavior is that the car will lock all doors with the key, and then immediately unlock them. Seems that the CCM is still very much alive.

Next steps are going to check all fuses, check the drivers door jamb for broken wires, and scan with VCDS for any codes.

To be honest, I'm hoping like heck that Oilhammer has seen this before and can point me in the right direction.

EDIT - Checked and the dome lamps are not working (by door or reading lamp switches), and the sunroof is inoperative as well. Lost the light and was unable to scan with VCDS - will do that tomorrow.

In front of the CCM a little ways, five brown ground wires splice into one. I would give that a tug, see if they all have solid connections. Mine did not, and the variety of electrical odd things went away when I rehabbed those connections.

Yep, that splice down at the base of the A-pillar.

Your water intrusion may be from stopped up drains in the cowl area, below the master cylinder/battery area. Right next to the heater hose pass-through is a grommet that gets stopped up... then water finds its way through the cabin filter frame on the right side, and the electrical harness pass-through on the left (below the ECU holder).

Since this is not your only problem, I doubt this is pertinent, but I once had a 2001 Jetta that had the door locks keep unlocking. Randomly, but pretty frequently. And sometimes the lock command would not work. The CCM was getting all the correct signals when it should be, and nothing when it shouldn't be, as far as fob/switch type stuff was concerned. Turned out, the SRS module, which has the authority to send an unlock command to the CCM in the event of an accident, was randomly sending that signal. No crash detected, no DTCs, but that little parcel of "HOLY COW, WE'VE CRASHED, UNLOCK THE DOORS AND TURN ON THE HAZARD LIGHTS" kept being sent. New SRS module fixed it.

I've been having the water issue for a while and the random door issues and other electrical stuff that comes with it. Last year I got fed up and relocated the CCM. Removed it from the box and tucked it under the dash. This didn't fix the problems but at leas now it can't get wet anymore. My grounds were very rusty too maybe I will look at them again and replace all the rusty stuff and relocate the ground from under the carpet to somewhere dry. Those ground points are very close to the dead pedal and all the water/salt that gets the dead pedal area wet destroys the grounds. Also, I've tried chasing the water intrusion last year and I thought I fixed it but doesn't look like I did. However, to drain any future water from under the driver seat, I drilled holes in the floor pan grommets in the passenger seat foot well when I had the carpet up. Glad I did because the first time I park hose first up a hill, a bunch of water drained out of the holes.

Found it

Was a 12v splice in the harness leading to the CCM. Little itty bit of green growing thanks to the water intrusion. Caused all of the CCM controlled systems to fail at once.

https://i.imgur.com/4ivyvqt.jpg

https://i.imgur.com/2CDZsSm.jpg

Those "inter-harness" splices are always a source of problems for any car. Lots of Fords and Nissans have similar issues. They just cannot seem to seal them up as well as they should, in case anything should happen to find its way in there moisture wise.

Windex said:

Found it

Was a 12v splice in the harness leading to the CCM. Little itty bit of green growing thanks to the water intrusion. Caused all of the CCM controlled systems to fail at once.

https://i.imgur.com/4ivyvqt.jpg

https://i.imgur.com/2CDZsSm.jpg

Click to expand...

Hmm...I wonder if I have the same issue. Thanks for posting this, I will check mine soon too.

There are 4 or so splices in the harness around the CCM. I would carefully check all of them, especially CCM powers and grounds and the ground splice nut on the floor at the base of the A pillar

Good information, for what seems like a common issue. My car was having the same issue, and will be looking into this. Wish we could add this to the "how to threads/ posts".

Hmmmm - same issue as Windex popped up today - door ajar symbol, windows don't work - not sure what else yet. I found with the door open, if I moved the rubber boot that the wiring runs through that it would intermittently work - I figgered I would have to pull the darn door off. So do I just need to pull of the kick panel to get at the wiring harness then? oh, and sorry to be so dumb, but what is the "CCM"?

Thanks all,

Darren

Comfort control module. It controls most of the body systems, including door locks, windows, etc.

Interesting... I may have a second look at my similar issue.

Windex said:

Comfort control module. It controls most of the body systems, including door locks, windows, etc.

Click to expand...

If the CCM is the located under the driver seat in a black sealed box, I have tried replacing it without much success. All it did was removed some of the features the car had before (wouldn't open the trunk) but didn't fix any of the other issues (some lock/windows not working). The replacement part has the same exact part number.

Windex said:

There are 4 or so splices in the harness around the CCM. I would carefully check all of them, especially CCM powers and grounds and the ground splice nut on the floor at the base of the A pillar

Click to expand...

The comfort system CAN bus wires also all splice together somewhere near the central module under the floor. ALL the switch information and commands travel on those two wires to and from all the door modules and the central module. Those are the absolute most critical wires in the entire system.

Touaregs are very well known for corroding comfort CAN wires under the driver's floor and creating all kinds of issues and a parasitic draw.

imo000 said:

If the CCM is the located under the driver seat in a black sealed box, I have tried replacing it without much success. All it did was removed some of the features the car had before (wouldn't open the trunk) but didn't fix any of the other issues (some lock/windows not working). The replacement part has the same exact part number.

Click to expand...

The CCM is programmable depending on the options in the car.

Maybe the one you got is from a wagon?

Majority of threads I have read through show water damage in the CCM to be the issue, followed closely by the wiring in that same area.

How was the connector for the CCM - any green terminals?

Matt-98AHU said:

The comfort system CAN bus wires also all splice together somewhere near the central module under the floor. ALL the switch information and commands travel on those two wires to and from all the door modules and the central module. Those are the absolute most critical wires in the entire system.
Touaregs are very well known for corroding comfort CAN wires under the driver's floor and creating all kinds of issues and a parasitic draw.

Click to expand...

Did not know this - good to know.

Windex said:

The CCM is programmable depending on the options in the car.
Maybe the one you got is from a wagon?
Majority of threads I have read through show water damage in the CCM to be the issue, followed closely by the wiring in that same area.
How was the connector for the CCM - any green terminals?

Click to expand...

This, 1000%.

Annoyingly, when VW made the change to the higher speed data bus that carries a few more messages in the CAN system around 2002, the central modules got ALL THE SAME PART NUMBERS.

New Beetles, Jettas, Jetta wagons, Golfs, Passats, Passat wagons mid 2002 and newer all use 1C0 959 799 C part number central module (except some later New Beetles that for some reason changed to the crank window address 35 central lock module rather than keeping the more integrated comfort system module, address 46 even though they still had power windows...but I digress). Except every one of them has a different logic and different pin locations for the trunk/hatch operation in particular. Getting the wrong module programmed for a sedan when you have a wagon or vice versa will create problems...

The only way to know for sure what you have if you buy a module blindly online by that part number is to plug it into the car, login with the scan tool and pull the 2 or 3 digit "color code" (VCDS can see what it is) and see if it matches what your old one says.

Sadly, it's not just simple coding changes that can fix it via VCDS. It's deeper programming than that. If you had at least the main config bytes figured out you could reprogram one using something like VDS Pro, but it's definitely way easier to just get the correct module to begin with... that is if the seller actually told you what bodystyle it came out of.