Originally Posted by jfoj

If you can lock and/or unlock the front doors with the interior master door lock switch, then the door lock actuators are connected.

The General Module relays are know to go bad in these vehicles, not sure if the E53 has a GM5 or other GM module. You are dealing with a 13 year old vehicle and things do not last forever.

You may also have a combination of problems, maybe a bad GM relay for the drivers door and a bad passenger door lock actuator?

See www.bmwgm5.com for more info.