The central locking on the KH started automatically locking the car doors even tho the drivers door was open. I checked the door switch and noticed it seemed a little loose or worn so swapped it with one of the rears which looked fine, (they just pop out).

Anyhow problem persisted. When I checked I found that if you open the drivers door the red door lamp comes on as expected so the switch is working, but the interior lamp doesn't come on :confused: and then eventually the system will automatically lock the doors again as if the drivers door is closed.

Anyone know what may be happening?

You may find the front door switch has 2 pins in it where as the rear door switch has 1 pin, same plug but missing pin. Get a switch from a front door and this should fix the issue, the BEM is not picking up the door has been opened and thus is locking the car thinking the unlock was accidently pushed

Had this erratic lock/unlock problem in my TL when I bought it. Dealer had simply removed the fuse for central locking to "hide" the problem. lol
Hit a bump and the four doors would go into a lock/unlock cycle endlessly. Unlocking the car with the key would result in an instant lock on all 4 doors.

The driver's door switch on the back of the door lock activates the lock mechanism on that door, which in turn activates all of the other door locks.
If swapping switches doesn't improve things, pull the driver's door mechanism out, and dismantle it. There are a couple of sliding contacts in it that need a bit of a bend to increase contact force.
Worked on my car anyway.

Oh, this just reminded me about me weird lock/unlock thingy that happens when I try to lock or unlock my TH. Sometimes unlocking will unlock, lock, unlock again (and the same with locking). Rather odd. Not sure if it would be a similar issue, but I might try and pull it out and have a look.

Pity I didn't take photos when I did mine. A fading memory now. Just go slow once it is out of the car and look where all the bits go once you open it up, so it goes back right. You can test it without putting it back in the door, just plug it in and work the bits.

Thanks for this info guys, I will check it out.

Oh, this just reminded me about me weird lock/unlock thingy that happens when I try to lock or unlock my TH. Sometimes unlocking will unlock, lock, unlock again (and the same with locking). Rather odd. Not sure if it would be a similar issue, but I might try and pull it out and have a look.

Sounds like there is an issue with the unlocking mechanism? I know that if you have the key turned to acc or on, and flip the drivers lock snib to the lock position and hold it there, the snib will try to return to the unlock position. It cant, so it keeps trying (can't remember how many times, maybe 5?) then stops. That might be what you're experiencing?

Sounds like there is an issue with the unlocking mechanism? I know that if you have the key turned to acc or on, and flip the drivers lock snib to the lock position and hold it there, the snib will try to return to the unlock position. It cant, so it keeps trying (can't remember how many times, maybe 5?) then stops. That might be what you're experiencing?

Hmm... Thanks for that. I'll have a look into it. It's no big problem at the moment, just annoying.