I have a 2000 reg S500 LWB pertol all my central locking, rear head rests, self closing doors and fuel filler cap have stopped working as of yesterday. has anybody got any information on what might be the course or has anybody experienced a similar problem? I would welcome any information, is it as simple as a fuse blown?

 

Could be a fuse, but doubtful. Try checking the PSE pump fuses (I have two fuses that indicate PSE pump) and fuse with central locking identity. I had similar issues when myPSE pump failed in January 2008, aftermany years of usage. I have two pumps, one in truck that controls self closing doors and trunk lid (I removed and cleaned this pump and all is well). the second pump called PSE pump is under my right passenger seat. What went wrong was the vacuum line to vacuum block for reserve vacuum either has a leak or the vacuum block leaks on this one circuit. Consequently the PSE pump runs all the time when switch is on. Eventually it hurt the pump a lot. I fixed the leaking line. I was very lucky and found a rebuilt PSE pump on eBay with exact part number as it fits several other models. You may have only one pump that serves all functions. If you need a new pump, locate it and get the part number and start the search on the internet. A more generic pump is also available with vacuum hoses modification needed, but not hard to do. Let us know if we can assist.

 

SAM Unit Failure, not sure which one, I'm having the same issue as of a week ago.

 

The pump under the seat controls lock/unlock, lumbars, provides backup vacuum for HVAC. It could be as easy as the fuse, or a bad pump, if it runs and then shuts off, it has both timing, and sensor safeties.