Faulty Comfort Control Module.. Any Ideas?

[ChrisWerrett]

I'm Looking for some help with some electrical problems with my interior lights, locks and boot mechanism on my 2004 Fabia vRS.

 

My boot hasn't really worked for the the past 6 months or so. I've recently replaced the servo and it works now, well sort of.

 

The riddle I am trying to solve is as follows.

 

When the car is running the boot switch works, if i switch it off it doesn't, when i switch it back on it continues to not work until I have opened the doors going round the car starting at the drives door, OS passenger door, N/S passenger door. once I have opened the N/S passenger door and the car is running the boot opens again. If I lock the car and press the boot button on the fob it works, if I unlock the car then try and open the boot, it doesn't work. My interior lights and door lights are also not working, however when I open the drivers door and headlight lights are on the tone sounds when the car is switched off, suggesting the micro switch in the door is working. When I open each door in turn with the engine on I can see the open door Icon illuminating on the dash, suggesting each microswitch is working. if the car is turned off no door light is visible.. I can't remember if it ever did illuminate without the key in the ignition? all doors lock as they should with the fob. Immobiliser LED flashing and all seems to work fine. If I flick the switch on my interior lights to on, then close and lock the doors the interior lights come on. when I unlock the doors they go off. basically the exact opposite of what the should be doing. I've bought a replacement comfort control module but haven't fitted it yet. Is this likely to be a CCM issue or something else? Keen to get some thoughts on this as I don't know where to start with this strange problem and I don't want to start replacing microswitches and dismantling to doors unless I really have to.

 

Any help much appreciated.

 

Chris

 

 

[Breezy_Pete]

What is the part number of the module you've bought? There are two modules that are often confused. One deals with central locking and alarm, the other does lots of other things.

 

You've done a great job of investigating the behaviours and describing your findings, but I think it's too late in the day for me to focus enough to interpret them.

 

Will revisit tomorrow.

[ChrisWerrett]

Hi Pete, thanks for your comment. The part I have bought is 6Q1 937 049 D It's the module that sits under the dash above the ODB port as for as I'm aware (Ive not taken my current module out just yet). Looking forwards to hearing your thoughts on it tomorrow. 

[Breezy_Pete]

That sounds like you've chosen the most appropriate one. 

I'm not saying that it is the problem, but from what I skim-read above, I  think the other one, above clutch pedal, probably isn't involved as it does Central Locking of all doors except the tailgate,  and I think you've described all of those as working OK.

 

Have you looked for wire breakages in any of the door bellows? Or signs of water ingress and corrosion of connector contacts?

 

 

[Breezy_Pete]

One more question to ponder; 

how dry versus leaky would you rate the cabin of your car, and how long have you owned it for?

I think I've come across a similar problem in a car that had condensation corrosion on some of the relevant pins of the connectors to this module, known in wiring diagrams as the Onboard Supply Control Module, and in VCDS as Central Electronics. 

[ChrisWerrett]

I've owned the car over 10 years but its been sitting on the drive most of the last year, and not had a whole lot of love for the last 3 years or so. I've got a transporter campervan which has taken up most of my time and a fair bit of money, but I'm trying to make a bit of time and effort to get the car back up to a good standard this year. It's a good fun little run around.

 

The issues have become more of an prominent over the last year or so, first it was the odd time something wouldn't work then it's got worse and worse! I do need to properly seal the back doors, there has been some pretty bad leaking and condensation in the car and it's on my list to do this week. I've got the comfort control module because I thought the one in there might have corroded as you say, I actually started looking into it after seeing someone with a similar issue on their transporter and it turned out their comfort control unit was really corroded. Their problems with their van were similar to what I'd been struggling with with the car.

 

Do you know whether I will need to get the new comfort control module programed in if I swap them?

[Breezy_Pete]

Coding is only needed in terms of configuration details, 2 minute VCDS job. 

Happy to do that for if you don't have such kit, and maybe you're local-ish?

[ChrisWerrett]

I've not checked the bellows yet. I ran out of light today but that's on my list of things to do after seeing a few mentions on here and youtube. There was a bit of corrosion on the pins for the boot latch in the lid but the switch seemed to be working OK: if I operated the latch with a screwdriver I could see the boot open light going on and off on the dash as it should. I think there was a washer fluid leak at one point which probably caused this but I fixed it years ago. What's the best way of cleaning up the pins if there is a bit of corrosion on them?

[Breezy_Pete]

I tend to use extremely fine grade wet and dry paper, lubed with contact cleaner, gently.

Catch you tomorrow.  🙂

[ChrisWerrett]

Sorry, I forgot to reply to this! I've managed to get it all sorted. I checked all the connectors for the doors and there was a bit of corrosion on some of the pins. I cleaned everything up with WD40 contact cleaner. I changed the comfort module too and everything is working (almost) perfectly again. I'm still getting a little bit of flickering on my interior lights, but I'm planning to take the module out and give that a clean too as I think there is a poor connection inside. I've also resealed the back doors. they had been done at some point but the silicone hadn't been applied that well so there was a bit of water coming through.

 

thanks again for your help!