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Beeping w/ DESS Key Off?

JKolbfleisch

New Member
I've searched on here as well as other sources and can't seem to find an answer. Ski is a 2002 GTX 4tec 155. When I connect the battery, it is silent for about 5 seconds and then I hear a relay click and it starts beeping, WITHOUT the key on. My gauge cluster is dead and waiting on replacement so not currently plugged in. Any ideas why this would be beeping with no key? Will not start with or without DRSS key.
 
I had a pair of '02s back in the day. I had a no-start condition that was caused by a faulty socket on the MPEM. I would shake move the harness close to where it plugs into the MPEM and the ski would come to life (beeping) and start. Later, I replaced the MPEM and the problem was fixed.

The beep is a signal to the rider that the key is on the DESS post, the MPEM is powered, and the battery is discharging ... essentially, the MPEM is telling you to please start the ski or remove the lanyard so you don't kill the battery. The DESS post is simply a magnetic switch where the magnet in the cap closes the (normally open) switch contacts and allows power to flow to the MPEM. The security chip in the key talks to the ECU and allows the ski to start. I would bet your post switch contact is stuck or is intermittent.

The 2002 shop manual has a whole section for testing the DESS post.
 
I hate unresolved forum threads, so I wanted to close the loop up on this one. I had purchased a used but "tested and working" ECU from a vendor so I looked for other sources of failure. Unfortunately, I replaced the DESS post, ohm tested all wiring harness to MPEM and ECU and even purchased a Candoo system to read faults. I continued to have the intermittent Key-Off power, Failure to read ECU, and various odd faults that would then disappear if I let the ski sit for a few days, then return once ski fired up. Took the ski to a marine tech specializing in PWC and found the ECU to be bad. Most likely the ECU would cool down to stop internal shorts just long enough to startup once, but would then begin to internally short and need days to cool down again. Put a new ECU in, the symptoms immediately disappeared and I can reliably fire the ski up again. It runs fine without the cluster. I actually 3d printed out a cluster mount and wired in some really nice aftermarket GPS speedo, tach and fuel gauges to replace them. Only thing I don't have is the maintenance LCD but I have the Candoo. I just can't shell out $750 for a couple gauges. Thanks.
 
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