Door locking problem

[Drafrete]

Hi forum members,

I have an issue developed in my 2012 D4. The rear driver side door won't lock or unlock with the rest of the car. It looks like an electrical connection problem.

The initial symptom was the the door did not unlock with the rest of the car and stayed locked shut. it was not possible to manually unlock it from inside either. Thought it might have been an actuator failure so I took door panel off but failed to be able to move the lock so then took the car to my local indie who managed to get the door unlocked and open. But once put back together the door won't respond to the key or the lock button. We have replaced the rear passenger door actuator but the same issue persists. The door does now lock and unlock manually (from the inside), but won't respond electronically. So it looks like a communication issue.

I have connected the Gap tool and I get two door related error messages and I am hoping that someone might be able to recognised them and point me in the direction of the part of the system that may have a problem.

The errors are:
DDM - Driver Door B1A98-87 (2F) Local interconnection network bus circuit 1 - Bus signal message failure - missing a message
PDM - Passenger Door B1163-15 (6C) Left mirror heater output - general electrical failure - circuit short to battery or open

Are these likely to be related?
Any hints on where in the wiring I should start looking?

Thanks in advance.

[josh.huber]

Hi forum members,

I have an issue developed in my 2012 D4. The rear driver side door won't lock or unlock with the rest of the car. It looks like an electrical connection problem.

The initial symptom was the the door did not unlock with the rest of the car and stayed locked shut. it was not possible to manually unlock it from inside either. Thought it might have been an actuator failure so I took door panel off but failed to be able to move the lock so then took the car to my local indie who managed to get the door unlocked and open. But once put back together the door won't respond to the key or the lock button. We have replaced the rear passenger door actuator but the same issue persists. The door does now lock and unlock manually (from the inside), but won't respond electronically. So it looks like a communication issue.

I have connected the Gap tool and I get two door related error messages and I am hoping that someone might be able to recognised them and point me in the direction of the part of the system that may have a problem.

The errors are:
DDM - Driver Door B1A98-87 (2F) Local interconnection network bus circuit 1 - Bus signal message failure - missing a message
PDM - Passenger Door B1163-15 (6C) Left mirror heater output - general electrical failure - circuit short to battery or open

Are these likely to be related?
Any hints on where in the wiring I should start looking?

Thanks in advance.

Pretty common on these at that age.. Can be a pain to change. You need a door Lock actuator

[Eric SDV6SE]

OP says he replaced the actuator already Josh, could it be the replacement actuator is also dodgy?

I have a similar problem with the rear drivers side door, however on mine it still clunks with the remote but won't lock. Rest of the doors lock fine, except for rear drivers side. Alarm is triggered when you open the door. Need to pull the door trim off and have a looksee.

[DiscoJeffster]

Hi forum members,

I have an issue developed in my 2012 D4. The rear driver side door won't lock or unlock with the rest of the car. It looks like an electrical connection problem.

The initial symptom was the the door did not unlock with the rest of the car and stayed locked shut. it was not possible to manually unlock it from inside either. Thought it might have been an actuator failure so I took door panel off but failed to be able to move the lock so then took the car to my local indie who managed to get the door unlocked and open. But once put back together the door won't respond to the key or the lock button. We have replaced the rear passenger door actuator but the same issue persists. The door does now lock and unlock manually (from the inside), but won't respond electronically. So it looks like a communication issue.

I have connected the Gap tool and I get two door related error messages and I am hoping that someone might be able to recognised them and point me in the direction of the part of the system that may have a problem.

The errors are:
DDM - Driver Door B1A98-87 (2F) Local interconnection network bus circuit 1 - Bus signal message failure - missing a message
PDM - Passenger Door B1163-15 (6C) Left mirror heater output - general electrical failure - circuit short to battery or open

Are these likely to be related?
Any hints on where in the wiring I should start looking?

Thanks in advance.

I’m confused. One minute you say the drivers rear door and then the passenger rear door. Which is it and which did you fix?
So you’re saying your Indi gave up and couldn’t fix it?? Isn’t that their expertise- fixing cars?

Your errors seem to imply you might have a general wiring issue going into the door. Maybe pull back the harness where it goes between the body and the door and check for damaged wiring?
Re-reading you have errors for both. I am confused.

[Drafrete]

Thanks to all who responded.

Yes, I have replaced the actuator in the rear door and the master control unit in the drivers door with new ones and the problem persists.

I have no sign of the passenger door error that I can see other than the error code from the GAP tool. I was wondering if they may be related or not. These are the only 2 errors reported for the car.

Looks like stripping out the wiring in the RH doors to try and trace a break is the best option.