PSE pump short? - Mercedes-Benz Forum

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post #1 of 6 (permalink) Old 06-29-2007, 02:42 PM Thread Starter
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PSE pump short?

Hi all, I have a question bout the PSE pump

Well it started with the car not turning on, a guy checked it out and told me when the light on the rear view mirror is red, your car isn't gonna turn on, and i remember how you had to unlock it to work (woops)....well after getting that sorted out, more problems came.

Lights in the car wouldn't turning on, you would open the door and no light, the light in the back wouldn't turn on from the switch, but the front would manually, not by the door opening. The seat could not be adjusted, and the side view mirrors cant either, nothing happens when u press the buttons

The trunk latch wouldn't come out, even though the trunk was open, and the trunk then wouldn't close but he managed to close it later, also locks wouldn't work.

So its the PSE pump from what i understand, but hes saying it somehow caused a short and made all the other stuff also not work. lol sory for the long story, but why would the pump cause those things to not work? Are side view mirrors, lights and seat adjustment all connected somehow?
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post #2 of 6 (permalink) Old 07-01-2007, 02:15 AM
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If I understand you well the only thing having to do with the PSE is the trunk latch. So why are you suspicious about the PSE? Malfunction of the trunk latch can have mechanic reason and could be managed via the upper hole on this frequently shown pic :

Best regards

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post #3 of 6 (permalink) Old 07-03-2007, 05:40 PM Thread Starter
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Thank you, but ive seen that picture, i tried it, didnt help lol

Actually i opened up the fuse box up front and saw one was tooken out, i duno if the guy was tryin to make us pay more or something by claiming the PSE pump affected some electronics

The only thing not working now is still the things having to do with PSE pump, but also the lights wont turn on when opening a door. And now the guy is saying the PSE pump provides air to the engine, thats why its working weird now. It HAS been making some more noises recently, and the car vibrates more then usual, but i didnt see anything online about the PSE pump providing air to engine.
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post #4 of 6 (permalink) Old 07-04-2007, 05:04 AM
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The PSE does various things, it provides pressure and vacuum to unlock the doors, trunk and fuel filler, It provided pressure for the lumbars, and it provides "back up" vacuum for your HVAC system when the engine is not producing any. This allows you to turn on the REST system for heat when the engine is not running. This also keeps the actuators fom closing during acceleration (no vacuum). It does not provide any vacuum to the engine unless the check valve fails to the reseroir. On some cars it provides for the trunk lid handle, the back up rods, and vacuum headrest if you dont have the electric seat.
There are electrial inputs from the switches in the front door handles and trunk for key lock and unlock, there is a connector from the alarm, and a connector from the infra red remote reciever, both of those devices are behind the liner near the fuel door. I think they can pull codes, but someone with knowledge should look at it. The red light means the alarm was not sucessfully set, and it could disable the starter intercept
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post #5 of 6 (permalink) Old 10-28-2008, 07:55 PM
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I'm having similiar issues with my 1999 SLK230, when my door is locked the alarm goes off. My fog lights are not going off, my interior light does not go out. I was also told it was the PSE Pump.
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post #6 of 6 (permalink) Old 10-31-2008, 11:05 AM
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CarolGS I have some good news for you maybe. I just posted earlier today that in my 1999 SLK 230 my door locks stopped working, and car alarm went off randomly. The interior dome light also stayed on persistently. I just followed Bazzle's post on taking the PSE Pump out and cleaning it with WD-40 and a soft Toothbrush, and my door locks started working again, and car alarm stopped, although my dome light remains on. I dont mind the light as I just keep it turned off. Checkout this thread. Will save you $800 US Dollars or so with less then 45 minutes of your own time (depending on how comfortable you are with electronics.

Take care!

1999 SLK 230, Sport Pkg, Auto, Special Order Obsidian Black Metallic, Oyster leather, First met on August 20, 1999
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