slk 280 on a 2006 plate

[drummer]

hi ihave a slk 280 0n a 2006 plate,the passengers door will not lock?the drivers side is ok.is there a fuse?or is it the keyfoob.any help please.i can push the door lock plunger down to lock the door in the mean time.

 

[LostKiwi]

The door locks are air driven by a pump in the boot. Do you hear a pump run for about 20-30 seconds when you unlock the car? If so you have an air leak on the line to that door, possibly a failed actuator.