This may sound stupid but when I open my drivers door sometimes the car doesn't recognize the drives door is open e.g. courtesy light not on when door opened after driving and no interior lights. So what tells the ECU that the door is open??

All others work ok

Thanks

can only be the door check switch..

Its called a door position monitor or Door control unit. The unit is inside the door casing, level with the door latch. It also monitors the central locking with all the door operating levers connected to it and some micro switches for the courtesy light. It is a known cause of central locking and courtesy light problems as the constant slamming of the car door dislodges the components and cracks the PCB terminals.

Its a pain to fix and quiete common throughout the VAG range.

Mine did the opposite to yours not long ago, the door contact switch decided it didnt want to work anymore and thought the door (drivers side) was always open, light was on dash, door lights and interior light was on etc

I took it to my local dealer and they put a whole new door catch system in it

Mine was done under warrenty but I imagine it would be quite expensive ?

This has just recently happened with mine, it's very temperamental and a bit annoying when I get in the car at night.

Its called a door position monitor or Door control unit. The unit is inside the door casing, level with the door latch. It also monitors the central locking with all the door operating levers connected to it and some micro switches for the courtesy light. It is a known cause of central locking and courtesy light problems as the constant slamming of the car door dislodges the components and cracks the PCB terminals.

Its a pain to fix and quiete common throughout the VAG range.

Would this be the reason why my central locking doesn't work when I press the buttons on my key fob?? I thought it might have been a dead battery in the fob but the car's an 05 plate, the battery shouldn't have died by now should it?

I thought it had to be comething more complicated then just a bog standard switch.

I take it when the door latch is operated it flicks a micro switch which tells the control unit to bring on the courtesy light. When you say it's a pain to fix can you re-solder the PCB or is it a new unit???

It use to happen to my MK4 golf too and I know the unit you mean

Thanks again

Its called a door position monitor or Door control unit. The unit is inside the door casing, level with the door latch. It also monitors the central locking with all the door operating levers connected to it and some micro switches for the courtesy light. It is a known cause of central locking and courtesy light problems as the constant slamming of the car door dislodges the components and cracks the PCB terminals.

Its a pain to fix and quiete common throughout the VAG range.

Would this be the reason why my central locking doesn't work when I press the buttons on my key fob?? I thought it might have been a dead battery in the fob but the car's an 05 plate, the battery shouldn't have died by now should it?

Yes it could be the Door position monitor but more likely to be something wrong with the remote part. Does everything work ok when opening car with the key, if yes then it will be the remote key problem.

Yes it could be the Door position monitor but more likely to be something wrong with the remote part. Does everything work ok when opening car with the key, if yes then it will be the remote key problem.

Yeah that's how I have to open it now, with the key in the door. If it's something to do with the key then I'll see if my spare set has a remote fob on it. Thanks.

I thought it had to be comething more complicated then just a bog standard switch.

I take it when the door latch is operated it flicks a micro switch which tells the control unit to bring on the courtesy light. When you say it's a pain to fix can you re-solder the PCB or is it a new unit???

It use to happen to my MK4 golf too and I know the unit you mean

Thanks again

Yes, there are microswitches inside, and probably the soldered connections broken, easily re-soldered once you remove the Door Position Monitor but that is the hard part.

I have similar problems with the Arosa but waiting for a spare whole day to attack it, and the door check strap mounting is broken away from the B post.