F/S/R Door lock button not working

[alan.gilchrist]

Hello

When pushing the lock buttons on the door handles all of the handles will lock the car except the far side rear door. has anyone esle had or been able to rectify this problem?

Thanks
Regards
Alan

[chevin]

Alan,

Have 11/03 car with Comfort Pack - so i've had these buttons for the last 6 years - since year 4 they all work intermittently. Although touch rust - only the rear passenger/drivers side is u/s at the moment. I suspect its just wear and tear as its the side I use most that seem to be the most unreliable. I think the cost of replacement has been quoted on here at £ 99 ea plus fitting - for 53 reg car I'll live with it untill the car hgoes in the Spring.

[megamike]

Hi, just about to post this problem for myself. Having searched the threads nobody seems to have explained the continuity involved. Both ends of the handle move but there is no sign of a wire so I am puzzled as to just what signal the button causes to activate the locking. It should be simple i.e. 2 contacts that touch but where does the circuit go from there? I've put it down to all the rain but copious WD40 doesn't work so maybe there is a techie who can help us?

[Skidms9]

2 common problems that cause this fault, both involving water ingress. 1st problem, water ingress into the button itself causing it to fail. A quick continuity test with a multi meter should show the switch opening and closing (or not in the case of a failed switch). 2nd problem, water ingress or misting of the the optical sensor causing it to show a constant 'active' signal when the UCH is interrogated, in turn causing the switch signal to be ignored by the UCH when it is pressed

It should be simple i.e. 2 contacts that touch but where does the circuit go from there? I've put it down to all the rain but copious WD40 doesn't work so maybe there is a techie who can help us?

All central locking information, whether hands-free or card controlled is handled by the UCH. Any other questions, just ask. Hope all this helps

[megamike]

Thanks Skidsm9, I'm a jack of all trades but master of none and don't know what UCH stands for. But anyway am I right in thnking I need to remove the inner door panel to get at the circuit points to test? Looking behind the button end when the handle is pulled open only shows what seems to be a rubber seal - or are the contacts behind that? The door will open on the sensor if car is locked in all other ways so it does seem to be just the button at fault.

[Skidms9]

My bad, UCH is the body control module. It handles things like wipers, central locking, electric windows etc. To get at the 2-pin button connector you'll need to lift the door flap only rather than pulling the whole panel off. You'll see the connector attached to the handle support inside the door cavity. You're right it does sound like a faulty button now you say the optical sensor is working. Good luck