Hi Folks
I've just been given a Citroen XM 2.1 TD, which is good, but it has a couple of niggles, all related to the alarm/central locking system.
1. The doors sometimes lock fine, and sometimes the locks bounce off again. They do this whether locked using remotes, or key in either front door, or button pushed from inside etc.
2. The alarm sometimes goes off for no good reason. Pushing the button to disbale the ultrasonics works but is a pain, and then there is the hassle of getting the car to stay locked again.
I can't even work out which lock might be stuck, or sticking.
Do the doors have sensor wiring attached to the locks which tells the central locking system that each door and tailgate has closed properly?
Wouldn't that show the problem on the dash with a door persistently appearing open even when shut..?
Anyway, any help or ideas appreciated.
Cheers
Russell [8D]
central locking problem
Moderator: RichardW
Hi Russell -
My BX central locks do exactly the same.
When I lock the doors by the key on drivers door - all locks first locks - then instantly unlocks again.
A second twist on the key immediately after - and they lock OK.
Only the front doors have a lock position sensor switch incorporated in the central lock motor.
The remaining lock motors are simple slave units.
The door unlocked warning lights are a separate circuit - working off a separate switch incorporated in the lock latching mechanism itself. These switches simply signals if the door locks are not latched correctly - i.e. when the door is catched on the outer latching.
As the doors are then not closed properly - you will most certainly also have the wind noise while driving.
In the boot and hud a separate switch is fitted - not incorporated in the locks.
My central locks problem is caused by my own lazyness - I don't really fancy stripping down the front doors to trace a faulty lock position switch or wiring - especially at this cold time of year.
It's a common problem to all cars with central locks (most cars these days !) - as the environment in the doors are humid and the cable bundle in the gaiter from door to pilar is strained every time you open the door.
As for the alarm problems - several owners have experinced the ultrasonic sensor units causes this. They simply stop working at some point - causing random alarm. Only effective cure is to to replace these units.
My BX central locks do exactly the same.
When I lock the doors by the key on drivers door - all locks first locks - then instantly unlocks again.
A second twist on the key immediately after - and they lock OK.
Only the front doors have a lock position sensor switch incorporated in the central lock motor.
The remaining lock motors are simple slave units.
The door unlocked warning lights are a separate circuit - working off a separate switch incorporated in the lock latching mechanism itself. These switches simply signals if the door locks are not latched correctly - i.e. when the door is catched on the outer latching.
As the doors are then not closed properly - you will most certainly also have the wind noise while driving.
In the boot and hud a separate switch is fitted - not incorporated in the locks.
My central locks problem is caused by my own lazyness - I don't really fancy stripping down the front doors to trace a faulty lock position switch or wiring - especially at this cold time of year.
It's a common problem to all cars with central locks (most cars these days !) - as the environment in the doors are humid and the cable bundle in the gaiter from door to pilar is strained every time you open the door.
As for the alarm problems - several owners have experinced the ultrasonic sensor units causes this. They simply stop working at some point - causing random alarm. Only effective cure is to to replace these units.
Hi Anders,
Ok, that makes sense.
I'm now in the state where I can't lock the car, but I can set the alarm!!
Do you know where the central locking controller is hidden, then I can monitor the signals to it when the doors are "locked" and hopefully deduce which door switch sensor needs taking apart, or mechanism is sticking.
thanks
Russell
Ok, that makes sense.
I'm now in the state where I can't lock the car, but I can set the alarm!!
Do you know where the central locking controller is hidden, then I can monitor the signals to it when the doors are "locked" and hopefully deduce which door switch sensor needs taking apart, or mechanism is sticking.
thanks
Russell
[:)] Hi just a thought. In the past what has caused bouncing locks on xms and xantias for me was a broken wire or wires in the loom that goes from the front door post to the door. Either door but more often the drivers door. Its easy to check, just pull back one end of the black cover to expose the wires. A steady pull on each wire is all that is needed pull out a broken wire or wires. Solder up and reinsulate. Good luck. [:D]
Just another quick thought before bed, the alarm going off fault. If you press the disable ultrasonics button and this stops it going off, then suspect the ultrasonic sensors. Easy to check. Get to the block connector of each individual sensor and disconnect. Get your trusty multimeter and check the continuty to each sensor. It should be open circuit. If u get a reading i.e any ohms reading, the sensor is at fault and should be replaced. Good luck. [:)]