Technical Right rear door indicated as not closed

[zefo]

Hello everyone,

as title the suggests, the right rear door is constantly indicated as not closed on dashboard.

As consequence, the car refuses the lock the doors with remote or key.
Mechanically, everything seems to be working fine. After locking the door manually, I can unlock them with remote.
When trying to lock the car, only the hazard lights flash 3x times, car refuses to lock.

Its either broken wire or broken switch in the locking mechanism?
The question is can, I test it, any ideas?

Has anyone schematics of BCM pinout and right door connector pinout with description?

Thanks!

 

[Herts Hillhopper]

Question: does the interior light work correctly (ie, comes on when any door is opened)? The same switch in the door latch turns on the light and reports the ‘door not closed’ warning.

 

[zefo]

The interior light stays on all the time, because the door is recognized as open.
Also the display show 'rear right door open', even when mechanically all doors are properly closed.

 

[Herts Hillhopper]

OK... in which case, here's some info that should help. (I've not put the diagram here as it's part of my subscription to Haynes AutoFix and covered by copyright)

Inside the rear door catch is a switch which closes when the door is open. That completes the circuit to the interior light and the 'door open' warning, by connecting them to 'earth'.

The wire that goes to that switch is white and green striped, and the wire from the switch to earth (the car body) is black. The earth point is inside the car, near the door pillar. With the door open, you should find +12V between the white/green wire and the body, and that should drop to 0V with the door (or at least, the catch) pushed shut. The 12V feed is shown as coming from 'F56' on the body computer module (which I assume means pin 56 of a plug marked F, but that isn't shown or at all clear in the diagram).

I suspect that either that switch in the latch has jammed in the 'on' position, or that somewhere else (probably where the wires pass between the bodyshell and the door) the white/green wire has been damaged and is 'shorting' to earth?

 

[zefo]

Hello Herts,

thanks for the great description of the wiring! Knowing what pins to measure and what to expect, made the fault finding so much easier.
I could see the +12V on the white-green cable, but I had to measure it against chassis. When measuring the black ground cable, it had no connection to the chassis.
Gently pulling on the cable revealed the issue.

The soldering was a bit fiddly but at least I avoided disassembling the door panels.

Thanks again, best regards!
Zefo