V50 Electrics : Offside doors not operating, front not even opening

[Swe50t]

Hi All, bought a V50 recently and it turned out to have a few more problems than I thought.

Most pressing matters are the offside doors.
Passanger door is completely bricked (except for speaker), the door stays locked even when pulling the handle from the inside. Can't operate the window and lock doesn't respond to any of the unlocking buttons, it feels like the PDM isn't communicating.
Rear left door isn't unlocking with button presses either, but I can at least open and manually lock it from the inside. The speaker is working here as well.
I got power on the harness to the door module, and the lock mechanism is giving feedback, like when the door is open the car tells me.
Driver door and rear right door are operating just fine, windows, buttons, locks, and speakers working as expected. The alarm system is working and triggering, it's happened out of the blue a couple of times but rarely.

I'm not sure where to take my investigation from here, I was hoping I had no power on the module despite the fuses being fine. At least it's be a power issue, not a communication issue.

Anyone got similar experience or have an idea of where to take it from here?
All help is appreciated 🙏

[PNM]

I don't have any experience of this on Volvo's, but I was recently asked by a friend to fix the same problem on a Vauxhall Zafira (deadlock actived and no response from key or central locking, but electric window and speakers working fine). Ended up taking the door card off, freeing off the deadlock with a long screwdriver and getting the door open. I then traced the wiring back and found a broken wire in the loom in the rubber sleeve between the door and the car. Fixed that wire, reassembled and all worked fine.

Also,.not sure if you've already seen this, but this might shed some light on things https://www.volvoforums.org.uk/showthread.php?t=253184

[Swe50t]

Thanks, more and more are pointing to the lock itself. I can't operate the windows on either door so taking off bits to reach the lock will be tricky, since I can't even open the front door I have to get it all off with the door shut which is a pain. I'll try to have a look at the loom for the rear door at last since I can open it.
A lot of threads point to the loom being worn, I find it odd to be both offside doors. If I've understood the wiring diagram correctly I guess it could also be the loom to the driver door? I found a great document, just having trouble understanding it 😅

[Brione]

I noticed in the original post you said that the fuses are fine.

From a problem I had with the rear passenger door I found they had individual fuses, this sorted my problem.

https://carsfuse.com/2008-2012-volvo...e-box-diagram/

I'm not sure what year your car is but hopefully this is of some help.

Good luck.

[iainmd]

I've had this before on both the drivers door and a rear door. Nightmare of a job. The door lock mechanism (an electronic part coded to the car) may have failed. I had this twice on my S40 and the dealer had to remove the door card from the inside which is incredibly difficult without breaking the tabs of the door card. The locking motor mechanism then need to be replaced and coded to the car before it's possible to release the deadlocks and open the door again. Cost (about 10yrs ago) was just under £400 to fix at a Volvo dealer.

Only other thought is a wiring loom issue. I think the DDM (Drivers Door Module) controls all the doors so the loom to the drivers door may have an issue. If you have one of the models with a connector on the drivers door frame you can try taking it off and cleaning it with electrical contact cleaner and see if that helps. If it's a wire break that's clearly not going to do much though.