PSE Pump/Central Locking Problem
 

I have a 92 400SE W140 that yesterday the Central Locking System stopped working. I first checked the fuses in the rear of the car and discovered the fuse (F4 # 9 20amp) had blown. What is interesting F4 # 9 specifically controls the “closing assist” function while F4 #3 fuse controls central locking, closing assist, and the PSE control module. I replaced the blow fuse and the central locking system worked for a few minutes before the fuse burned out again. I could hear the PSE pump under the rear seat running when I attempted to activate the central locking system. I replaced the blow fuse again (F4 # 9) but now the PSE pump does not run. I you attempt to use the Central Locking System, you will only hear a single, faint click noise coming from the PSE pump – no motor running. The door and trunk Closing Assist work fine, but none of the PSE controlled modules work.

Since the PSE only makes a faint, single click noise, is the PSE blown and needs to be replaced? Does anyone know why the fuse was blown on F4#3 for closing assist when the PSE pump (PSE is controlled by F4 #9) is not controlled by this fuse?

I also checked the vacuum lines that connect to the PSE pump and all connecting lines with the exception of 3 will hold a vacuum without loosing pressure. Do you think these 3 lines caused the PSE pump to fail due to overwork?

I can tell you that the vacuum pump in question has a rather high failure rate. It's definitely a big seller.

Ron
http://germanstar.net

I just went to get gas and the fuel door is locked in the close position because the PSE pump has quit. :( I'm unsure of which vacuum hose ( + or - ) pressure applied will relase the fuel door. As you can imagine, I'm really starting to get frustrated with the 400SE!@@

Is removing the rear seats and appling (vacuum or pressure) my only option to open the fuel door?

Does anyone know the "replacement" part number for the PSE pump listed above in the picture? I was told the part has been replaced with a newer "universal" pump. Is this true?

Thanks for any feedback.

fuel door
 

I think there is a pull (handle) on the assembly to retract it from the trunk. I also belive it is the extra yellow line from the pump, that also controls the gas door and the trunk handle, the other yellow controls lock/onlock on the doors. I was under the opinion there is a universal replacement pump with a separate distributor plate which can be adapted for you needs.