MK1 Cupra R CCM/ Window issue

[OllieMaccaa]

Hello all, new member here so thank you for having me.

I recently bought a mk1 2003 Seat Cupra R. It’s been lightly modified by a previous owner (someone before the owner that I purchased it from).

My issue: None of my windows work from the switches, (front and rear, both being electric). The windows go up and down when the lock and unlock button is held down on the key fob, so I know that it’s not a motor issue. I have tested the wiring from where it enters the chassis at the base of the A pillar and at the door where it connects to the motor and master switch. All the wires are showing perfect continuity and constant and switch live where it should be. This made me think that it was an issue with the comfort control module. I’ve also bought a new master switch for the drivers door and having the same issue.
I plugged in to VCDS and had the error message “cannot connect to module.”. So I bought another CCM, installed that with the battery disconnected, reconnected the battery and I get the same error in VCDS.
I took my multimeter to the brown plug that connects to the CCM, I’ve got constant live but no switch live to the black wire.

Am I checking the correct wire for switch live?
Has anybody else had a similar problem?
Could anyone shed any light on this?

I noticed that some of the wiring looks “non standard” as there is an aftermarket lighting module behind here and the headlight controls have been updated to a newer vag switch with auto lights.

I appreciate anyone that reads through this as I understand it’s a bit of an essay and a bit of a head scratcher (for me it is anyway)

 

[mty12345]

Have you checked the fuses?

 

[Battoussai]

And are you sure the new CCM is working? Is it new or from scrap? Also check for bend terminals that might avoid connection.

 

[OllieMaccaa]

Have you checked the fuses?

Checked all fuses with a multimeter and they have perfect continuity. Appreciate you replying

 

[OllieMaccaa]

And are you sure the new CCM is working? Is it new or from scrap? Also check for bend terminals that might avoid connection.

It’s from a breaker and it came off a working car with no issues. What do you mean by bend terminals sorry?
I’ve checked wiring from the car to the door, including through any joints such as the one at the base of the A pillar and the bend in the rubber between to door. Each wire is showing perfect continuity on a multimeter

 

[Battoussai]

It’s from a breaker and it came off a working car with no issues. What do you mean by bend terminals sorry?
I’ve checked wiring from the car to the door, including through any joints such as the one at the base of the A pillar and the bend in the rubber between to door. Each wire is showing perfect continuity on a multimeter

I mean bent inside the plugs. And have you tried to unplug the aftermarket auto light switch?

 

[OllieMaccaa]

All the plugs and pins are in decent visual condition from what I can see. I even took the board out of the CCM to look for corrosion or any signs of damage and there’s nothing. I’ve tried unplugging the aftermarket light controller as well. The frustrating thing is. The windows worked the day I bought the car. The previous owner started the car and wound the window down in front of me I think the fact that VCDS won’t connect to the CCM module, means it’s a wiring issue. I’m off this week so I’m hoping to get into it a bit more. I’ll post any updates

 

[Battoussai]

I might be wrong but I often read here on the forum that if you change the CCM it must be the exact same part number and that it needs to be coded with the same parameters of the old CCM. Maybe that's why VCDS isn't connecting to it at all? Maybe some experts could shed a light on this.

 

[OllieMaccaa]

I might be wrong but I often read here on the forum that if you change the CCM it must be the exact same part number and that it needs to be coded with the same parameters of the old CCM. Maybe that's why VCDS isn't connecting to it at all? Maybe some experts could shed a light on this.

Yeah they need to be coded to match the parameters of the old CCM, but both my old CCM and the new one are not able to be read in VCDS. The new one that I bought is also the same part number as my current one. This is making me think that it’s some sort of power or wiring issue.

 

[mty12345]

Yeah they need to be coded to match the parameters of the old CCM, but both my old CCM and the new one are not able to be read in VCDS. The new one that I bought is also the same part number as my current one. This is making me think that it’s some sort of power or wiring issue.

Yep, sounds like either you have no power, no ground, or the canbus (K-line) communication circuit is broken to that module.

 

[OllieMaccaa]

Yep, sounds like either you have no power, no ground, or the canbus (K-line) communication circuit is broken to that module.

Hoping for good weather tomorrow so that I can get it apart again and take my multimeter to everything. There’s not much material online to assist with what pins should do what on the CCM plugs. I’ve used chat gpt to try and help but it’s not very reliable