i have a 1999 c class c200 and the central locking and boot release on the key fob is not working? i have checked the fuses and all seem fine even the ones in the boot could this have anything to do with the sps pump as ive also replaced the batteries in the fob and they r working fine as the key fob still arms and de-activates the alarm fine any help would be very greatfull. i also own a 1998 c class and is it possible to swap them over to check weather it is the pump? and if so where is the sps pump located? cheers

 

Check to see if the key is giving off an IR signal. To do this use a camera phone and point it at the output of the key. As you are looking at the picture of the end of the key on your camera phone press the lock or unlock button. You should see a flashing light coming from the key when the buttons are pressed, indicating the ir function of the key is working. If it is ok then your problem could be in the overhead control panel. A sds could be used to check actual values when the key is pressed to see if it is working.