Trunk release

MEgearhead

Well-known member
Joined
Aug 6, 2016
Location
Virginia
TDI
B5.5, 4L
I have been trying to sort out an issue with the trunk actuator.

First the background: the sunroof leaked and the drain was plugged. Flooded the drivers footwell. Dried everything out and everything worked except the trunk release, and I couldn't reprogram the key fobs.

Traced the trunk release issue to a friend actuator. Verified proper trunk release operation of the CCM using a DVM at the actuator connector.

Purchased a used CCM on eBay to correct the keyless entry programming issue, and a new VW trunk release actuator. Installed both and was able to program the key fobs, but now the trunk will not stay closed.

If I close the trunk, in 2 seconds the actuator activates and opens it back up. It's like a Mr. Bean routine. I keep waiting for the doors to open and wipers to start. In addition, if I unlock the doors with the fob the trunk opens. I checked the trunk latch and end switch. They both operate correctly. The latch latches but 2 seconds after the end switch opens the CCM activates the actuator. If I unplug the actuator, close the trunk, wait more than 2 seconds, crawl through the back seat, and plug the actuator in, it will stay closed until the doors are unlocked.

I have verified the correct coding (258), and adaptation (Rest of World). The used CCM was the exact same part number as the originally installed one. Is there something I overlooked such as additional settings in the CCM. I don't know what else to try besides replacing the CCM again. I hate to spend $300 for a known good new CCM just for remote trunk release, but the akwardly placed trunk lock cylinder is annoying.

Thanks in advance for your help.
 
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MEgearhead

Well-known member
Joined
Aug 6, 2016
Location
Virginia
TDI
B5.5, 4L
Thanks for the suggestion. Already tried that. At this point I don't know what else to do except try a known good CCM. Thanks again!
 

QuickTD

Veteran Member
Joined
Feb 25, 2002
Location
SW Ontario
TDI
2003 Audi A4Q 5spd 2.0 TDI 2056VK R783, 2006 Audi A4Q 6spd 2.0 TDI
Check the CCM coding, I have a feeling it is coded for a wagon.
 

MEgearhead

Well-known member
Joined
Aug 6, 2016
Location
Virginia
TDI
B5.5, 4L
Thanks for the suggestion. I've checked and rechecked the coding. I didn't see any difference in coding between the wagon and sedan.

Central Locking (2 doors / 2-power windows):
00064 = Selective Locking
00065 = Unlocking of all doors

Central Locking (4 doors / 2-power windows):
00066 = Selective Locking
00067 = Unlocking of all doors

Central Locking (4 doors / 4-power windows):
00258 = Selective Locking
00259 = Unlocking of all doors

I've tried both 00258 and 00259. Is there other coding values?

I looked back at old autoscan logs, and 00258 was the coding for the original module.

I'm wondering if there's a difference in the parts even though they are both the same part number 1C0 959 799 C.

From autoscan logs of the original module:
Part No: 1C0 959 799 C
Component: 08 Komfortgerát HLO 0004

From autoscan logs of the used replacement module:
Part No: 1C0 959 799 C
Component: C7 Komfortgerát HLO 0003
 
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afarfalla

Veteran Member
Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
I would disassemble key lock module at the trunk above the rear license plate, maybe one of the switches is sending the wrong info to the CCM


Maybe the key micro switch is broke, or the open button
 

MEgearhead

Well-known member
Joined
Aug 6, 2016
Location
Virginia
TDI
B5.5, 4L
Thanks for all the suggestions. I have checked the wiring, the latch micro switch, the switch and lockout in the door, and the micro switch on the lock cylinder. Everything is good.

I finally looked up the part number for the CCM. Turns out there are several versions of part 1C0 959 799C. These are denoted by the equivalent of paint codes like 008 appended to the part number.

These codes don't seem to be printed on the part. So this makes buying a used one problematic, unless you get it from a similarly equipped same model. Jim Ellis VW shows 13 variants of part 1C0 959 799C, 5 of which are for the Passat. The description includes a note to provide the VIN.

I did notice that the autoscan of my original module has "08 Komfortgerát" under component. The used one I bought has "C7 Komfortgerát". The 08 and C7 line up with "paint codes" 008 and 0C7. All the "paint codes" for the different variants start with 0.

I believe I should have the 008 version (Passat sedan, 4 power windows with comfort feature, power mirrors, no memory, no folding mirrors). The 0C7 version is for a Golf with power windows and door and lid locking system.

If and when I can bring myself to come off the $360 for a new module I'll update with results.
 

MEgearhead

Well-known member
Joined
Aug 6, 2016
Location
Virginia
TDI
B5.5, 4L
Updating to close the loop in case someone else runs into this issue. I finally purchased a used CCM from a 05 Passat, and everything works perfectly, an autoscan of the new used module shows the same 08 code that the original one did. So, when purchasing a used CCM you cannot go solely on the part number printed on the part.
 
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