1999 GTX Limited MPEM problem

[obwon]

Hello,
I have a 1999 GTX Limited with yhe 951 carburated engine and I am having a problem with the MPEM. In order for the sytem to work, I have to pull and then replace the 5 amp fuse in the mpem. All the fuses are good and the battery is new and tests good. I recently aquired this ski and do not know the history of it. I have not run this yet as I have had to repair the motor ( stuck rings) and have rebuilt the carbs. I have used another post to test and have to do the same routine so I assume my post is good.
What I have to do is put on the DSS lanyard on the post and then pull out the 5 amp fuse on the MPEM and replace it (same fuse) then the machine beeps twice and I can engage the starter and get spark. If I do not put on the lanyard and pull and replace the fuse the machine will not beep or allow the start button to work when I put the lanyard on. The lanyard must be on first.
There is 12 volts going into the #3 plug on the MPEM and the 15 amp fuse in the coil compartment is good as are all the fuses in the MPEM.. I cannot get the diagnose program with the instrument cluster to go on by pushing the start/stop button 5 times either, but the instruments work after the 2 beeps.
Any ideas why the dss/MPEM sytem will not work normally and why does removing power and then receiving power to the MPEM work? I have tested the DSS key on the post and there is continuity with the "key" on and none with it off between the black/ yellow wire and the black wire from the post.
Dose this sound like the MPEM is faulty? Any ideas on how to repair this problem?

Thanks, John

 

[LouDoo]

The first thing I would do is check the condition of the battery. Put a voltmeter across the battery terminals and try to start, does the voltage drop below 10.5v if so you need a new battery. I'm not saying that's your problem, but is could be as simple as that.

Lou

 

[Dr Honda]

I've seen this a few times... and the MPEM is not happy. I'm not sure if the memory (internal program) is corrupt, or the transistor, internal of the MPEM, that controls the lanyard post has gone bad... but unfortunately... the fix is a new MPEM.

 

[obwon]

I have tested the battery and it is fine. Until I can get a a used MPEM, I think I may put jumpers in the 5amp fuse spot on the MPEM and hook up a fuse holder that is accessable while on the ski. Then I can remove / install the fuse when I need to start it. I am not even sure the ski will run properly with this setup, but will know this coming week.
I want to thank you for the replies and help, the dealer told me to make an appointment for early August?? to troubleshoot this problem. Any more thoughts on what could be the reason for this problem and how to correct it? Anyone have a used MPEM for sale with the # 278001398 or the new revision # 278001525 with a DSS key that is programmed for that MPEM?

Thanks, John