Brilliant thread thanks felas. I've got my passenger side door lock playing up as well (not locking when the key fob is pushed). When I get the car down here from home I'll try some of these suggestions and see if they result in a working locking mechanism. Of note, is the fact that the passenger door lock (left hand side in Oz) is blanked off. The previous owner mumbled something about the lock when I picked the car up and commented on the left side not locking. My car is a 04 160 Coupe, so my question is, does the passenger side lock accept a key or is it blanked off?
Thanks for any info and best wishes all.
Maybe I should have said the intent was to save the cost of the lock barrel by fitting blank passenger locks on remote central locking cars, but whatever was in the parts bin at the time may have been fitted.