When I lock the door with the drivers side lock all the doors lock fine but if I try locking or unlocking using the passenger side lock it does not activate the central locking system and locks/unlocks the passenger door.

Would this be a simple fix?

There are two microswitches inside the lock module that tell the system that the key has been turned. One of them could be faulty or have a bad solder joint. You would need a new lock module or to fix the bad solder joint(s) which requires the door stripping down. Stripping the door is not easy unless you're good with that kind of thing.

 

Numbers 1 & 2 in this pic are the key switches.....

 

 

Also check for broken wires inside the rubber door bellows and check for corrosion at the plugs/sockets.

 

 

 

Edited 8 November, 20205 yr by TMB