My 2005 RX8 does not lock or unlock using the remote in the keyfob. When using the key to manually lock or unlock, it does work intermittently but mostly the left side door would not unlock (this being a RH driven car). From the inside I am unable to sometime lock or unlock using the lever on the door. Would really appreciate any suggestion as to the possible solution. I have replaced the battery in the key, and the trunk/boot does open without any issues using the remote.

 

My guess is the door lock actuator.

Mine behaved similarly (although I was always able to use the lever inside) and it was fixed by replacing the door lock actuator.

The part number for the left door lock actuator for LHD cars is "FE01-59-310E". I don't know if it's the same for RHD cars but I'm guessing it is.

 

Hey Thanks mate ! I will have to see where to find a brand new actuator now.