I'm sure this has been discussed a lot. But I would like some guidance. I have an E320 (W210) 1996.

My central locking stopped working several months ago. All fuses are good. The key fob engages the PSE pump under the seat, but no action with the locks up or down. The security system engages and also lights up when using the remote. The door locks dash switch and the trunk switch do not engage the PSE pump (nothing happens). Here is one clue: if I manually lock the doors and inject compressed air, one of the rear doors does not go up. I have not as yet tried to test the lines under vacuum. All the locks are tied together (6 yellow lines). There is a gray air line and a white air line. I believe one of them goes to the engine vacuum lines. Before I order a pump replacement, it would be good to get some ideas.

TNX
Peter

 

OK...well frankly I did not join this forum (yesterday) to be told to go to someone else for diagnostic help. Replacement pumps are not that expensive and are easy to replace. The other issue is the only MB shop in this area that I trusted, closed (they retired). So I need to do what I can until I find a new service shop around here.

 

Use the advanced search feature in the upper right corner of the screen. You will find numerous posts by folks who were troubleshooting their vacuum locks.

 

Yes thank you....I have been reading some of them. I also realized it is time for a better scanner......

 

if you buy a replacement pump, new or used, you may still need an MB diagnostic tool to reset the PSE pump to ensure that it handshakes with the proper appliances.

generally positive pressure handles unlocking while negative pressure (vacuum) performs locking. the air hoses become brittle over time and by now, we're talking about 20+ year old plastic hoses. They tend to fracture first at the end and T connectors....or at a location near a hinge (flexing back and forth)

 

Yes TNX. I suspect a leak and ordered a hand pump test kit to check out the lines.

 

Fixed it. Found the leak, a mouse had eaten into the air line to the left rear door. Fortunately it was in a spot I could get to. I spliced the line and tested the vacuum (with new hand pump)...all was good. I used the method mentioned in another topic or forum: used a spray can nozzle extender to join the pieces and used .170 ID rubber hose over it, all set with superglue. Locks are back to normal.

TNX for the help for those who posted.

Peter

 

Another fix for a leak to consider would be the which is self sealing. Stretches and seals wonderfully and I always keep extra rolls around the garage for misc fixes