Slk230 Alarm

[RST]

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?