Hey guys,

Having some issues with my Z's central locking system and I have no clue what to do so hoping for some advice.

If I lock the car with the original key fob, only the passenger door locks.

If I use the main switch on the driver's door to lock the car, only the passenger door locks.

If I manually push the lock switch on the door itself, both doors lock.

If I use the key to lock the car, both doors lock.

Is this most likely a faulty door actuator ? If so how difficult is changing it ? I couldn't seem to find a guide