I purchased an ’01 SLK230 in November 2004. It had some electrical problems when I first got it, but these were corrected under warranty by my local dealer. Since then everything has been fine until about two weeks ago when the alarm went off when I pushed the door lock button on the key. I tried putting the key in the ignition and turning it, but nothing I could do would turn the alarm off. It ran through its three-minute cycle and then turned off automatically. The top was down when this problem occurred, so I put the top up and tried it again with the same results.

I took the car (now out of warranty) to the dealer for diagnosis and received the following report: “15958 function test read erase codes B1712/B1709 Alarm Faulty Activation through front doors R and R PSE Pump to inspect corroded connections requires replacement.” The conclusion was that I needed to replace the PSE pump. Because the PSE pump appeared to be doing its job – activating door locks, top, etc. -- I questioned whether replacement was really necessary, and decided to do some research first.

After reading the posts on this site regarding alarms and PSE pumps, I have some comments and questions. I looked at the PSE pump and did not see any evidence of water reaching it. None of the connections that I could see (without removing the pump) looked corroded. As I said, the pump seems to operate all of the systems; the only problem is with the logic and the alarm. I was wondering whether something could have affected the programming of the chip that interfaces between the mechanical portions of the pump and the alarm. Is it possible to change out the chip, or reprogram it, or clean whatever connections might be corroded, without replacing an otherwise operable pump?

That is a common on those cars. Either a pump failure OR water getting into the pump thru the connector.

Try finding a good used (recycled) part, should go for 1/4 the cost of a new replacement & shouldn't need to be re-coded as long as the part numbers match!

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Anyone know the cause of the water in the pump? where does it get in (through the wiring I assume)

Tons of these I have seen that have "fuzzy" green corroded connectors, a worst case one I had last week where the pump wouldn't run, it had corroded so much, the connectors, circuit board on both sides and the motor burnt up and melted itself to the circuit board.

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1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

Just had my PSE replaced this week £504 the old one was a mess completely totalled. The foam covering was really wet which was the first sign, I thought at first I could take it out and dry it, wrong. Later models 2004 the pump is fitted upside down but when I asked the dealer to do the same it was not possible because the wires etc were too short so its now in a plastic bag. I think the water came in and went down the wires but I have a problem with water drainage, the drain tube behind the rear wheels never seems to drain I have to press my finger/screwdriver in to release any water. When I inspected the PSE when the faults happened the water that came out of that drain tube would have filled a small swimming pool, so the problem could have been there. The attached pics are as the pump was fitted in my car. Sorry about the pic size.

Attached Thumbnails

 

Thanks for the post, it may be helping me understand the problem a little better. The photos Gary posted are of the the PSE "control module." I believe the PSE pump resides directly above it in the compartment accessible from the trunk. In my case, the pump is manufactured by Hoerbiger in Germany and bears several numbers: A170 800 00300, 180221, and HB92907-100.

I believe the PSE "pump" in my car works fine. However, I can easily believe that the PSE "control module" is the cause of the problem, which seems to be a communication problem between the pump and the alarm system. It looks as though the "control module" would be less expensive and easier to replace than the "pump."

Does anyone know of a good source for a replacement PSE control module. Alternatively, if one does not care about having the use of the alarm, is there any reason why the other sysetms connected to the PSE pump will not operate correctly if the alarm horn is disconnected?