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Trying again for any response

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mrlmd1

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DESS and MPEM question - 56 views, no response from anyone, trying again so maybe someone will see this.
I have a '97 GS which ran perfectly 6 months ago and haven't been able to use it for a variety of reasons. It sat covered up on a jetski float at my dock connected to a 1.5 amp small solar panel trickle charger to keep the battery up but I went to start it recently and the battery was way down, like 9v, not maintained by the charger even though it's putting out 14.5-14.7v trickle. I removed the battery, brought it into the house and resurrected it over a few days with a 2 amp charger. When I reinstalled it and put on my key, I get one red flash lasting about 2 sec on the dash, no beeps, no response at all when I press the start button - no relay click, starter clicks, etc. I jumped it from another 12v regular size battery from a golf cart and no change - just one red 2 sec light with the key on, nothing else, no other noises except that from the start button. I took apart all the cable connections and cleaned off all corrosion at the battery terminals and those on the heavy red cables in the box on the right side of the engine compartment which didn't change anything. No fuses are blown (by looking at them).
My question is, if there's no juice to the MPEM for a while (? months) does this have to be programmed to the DESS key again ( I have 3 of them, 2 brand new previously programmed to the ski, and none of them work any differently), or does the code in there change at all without juice going to it? Before I start digging looking for why there's no power to it, I need to know this as could it be that all I have to do is go back to the dealer and interrogate it and getting another matching DESS? If this is not the case, then I don't know where to begin looking for the problem. I could try and short or bypass the starter relay to see if it kicks over but why no handshake between the DESS keys and MPEM?
Thanks a lot for any suggestions or help.
Sorry for the second post of this.
 
Sorry you didn't get a responce... but I think it's because it's a tough issue.


OK... if you are getting power up to the light on the dash... then there is power to the MPEM.

I would start by trying to go into advance mode.

1) press your starter button 5 times, and you should get a short and a long beep.

2) after the beep, install the lanyard, and press the start button one time. You will get new beeps.

Do that, and tell us what beeps you get.


As far as "will the MPEM loose it's memory"... no, it shouldn't, but it has been known to happen. I personally disconcert the battery of my toys over the winter, because there is more of a chance of messing up the MPEM with a battery charger than letting it sit without a battery.

I know you have a small solar charger... but if it made a power spike, or a short... it could have messed up your MPEM.
 
Let the battery sit for a day without being on the charger. If it holds 12.0v or less it is NG and needs to be replaced. Should be up to 12.5-12.8v and hold for days.
 
Charge the battery, and then it can be LOAD tested at an auto part store. It could have voltage but not CCAs. My guess is that you had just enough battery draw to
activate electrologis corrosion on the cable and/or harness connectors. I recommend
you disconnect one at a time, clean & di-electric grease each connector, post, pin,
(mpem) fuse holder, cable, and cut any ground lug and replace it by soldering & heat
shrink-wrap it. This may take two hours to complete. Test each componet along the way, so you only have to do this harness thing only once! Bills86e

Hope ya grease your carb(s) exterior,selector valve, linkages, cables, latches, Zerks.
 
I know about having a good battery, and I connected with jumper cables to the battery in the ski a fully charged 12v auto battery and got the same response = nothing except one short red light on the dash under the oil logo.
I believe my buzzer is out and I don't know where it is located. Is it under the body up front or buried under the handlebar/dash area? I once tried to take that apart to look for it and it was a bitch and I gave up before, but if there is a trick to getting that apart I'd like to know.
By the way, that little solar charger doesn't even put out 1 amp, so there is no way to get a "surge" out of that to blow the MPEM, and the 5 amp fuse is intact.
Dr. Honda - I did what you suggested, hitting the start button 5 times and all I get (with or without the DESS attached) is one short light as before as soon as I first hit the button, I don't get 5 lights on hitting it each time, and if I put the key on within a few seconds, when I again hit the start button, there is nothing, not even the light comes on. There seems to be a built in delay for the light, in other words, I have to wait a few seconds before hitting the start button for it to come on again, and it makes no difference if the DESS is attached or not.
Bills86e- I cleaned the battery terminals and all the red cable ends of corrosion in the electrical box on the right side of the motor compartment and can't even see or know how to get to the ones at the starter or ground. They are buried underneath the engine. But wouldn't there be enough power for the handshake between MPEM and the DESS, regardless if the starter turns over or not? I should be getting 2 light flashes and 2 beeps when I put the key on, not nothing except one light when I press the start button with or without the key on. I'll check for any bad connections in the plug that attaches to the MPEM. The first problem is to get the ski to recognize my DESS, then maybe have to work to start it. If the DESS isn't recognized, then nothing else will work, regardless of Volts or CCA's. Maybe my terminal on the handlebars that the DESS snaps onto is somehow not working because of corrossion or a disconnected wire. It was running a few months ago perfectly and nothing has been done to the ski or has changed except the battery discharged some.
 
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The buzzer is in your Shop Manual, The di-electrical grease is at the Auto Part store.
 
An update - with a battery reading 12.7v attached there's no change. Only 1 red light when either the starter button is pressed or the DESS key is attached to the post. To me that means the starter button is working and that the DESS post is intact. If I jump the starter contacts for a second, the starter engages, I didn't leave it on long enough to see if it starts and runs. I cleaned all the contacts of corrosion I could find. The contacts on all the connections under the forward hull are also clean as well as the ones going to the MPEM and those in the rear electrical box. The memory chip in the MPEM shouldn't change when it loses power or is disconnected, and nothing should change in the 3 DESS keys I have.
The basic problem is that the DESS key is not getting recognized by the MPEM when I attach it. Any new thoughts on where the problem could be?:confused:

And Bill86e, I really appreciate all the kind help and thoughtful advice you have given me, but sometimes it's more prudent to say "Gee, I'm stumped" instead of telling me to look in the manual or the auto parts store. That's no advice to someone asking a question of more informed members on here who may actually want to help and offer some advice.:cheers:
 
maybe your relay(starter solenoid) is bad. You got juice to the one post, you jump it, and turns over the starter. Sounds like relay to me.

In the rear ebox, i think theres a little red wire thats suppose to be attch to the post, that the battery lead attaches to.
 
If the starter relay was bad, how would that prevent the handshake between the DEES key and MPEM? That's my basic problem. A bad relay would still allow a handshake but not energize the starter when the button is pressed. That's a different problem.There is no clicking or noise from the relay which could mean it is bad, or it is not being energized because there's no handshake. I have to have some clue as to what is wrong besides just replacing parts at will and hoping something will work.
I have 2 leads on the top of the starter relay - one red heavy lead from the battery going in and the other heavy red lead going out to the starter from the other terminal of the relay. That's what I jumped to activate the starter.
There are 2 other lighter leads going into the other (bottom) end of the relay to activate it, (via a plug-in connector which is dry and clean), I guess from the starter button. Are those what you are talking about? I don't have another little red wire that attaches to the battery post connection in the rear ebox and I don't have an extra loose wire hanging around in that box.
I guess I have to get or download a wiring diagram to see where the MPEM fits into the circuit. Is that in the manual if I download it?
And that still sheds no light on my problem and where to look. The MPEM looks brand new and was never overcharged, the fuses are good, one day the ski runs, then it doesn't. It shouldn't crap out just like that sitting there so I don't think the MPEM is the problem. There has to be a bad wire somewhere or corroded connection - I'm asking for suggestions on where to look or what to test.
 
didnt read/catch that part. This thread get'n "heavy". If by chance, you/neighbor/friend, has a seadoo, with dess system, remove the post, and try on your doo.
 
Mrlmd1,
I too am having a similar problem, for years now actually. Mine is a '98 GTS with the 717/720 engine. Mine too will recognize the key with the familiar "chirp-chirp", then a some time later, no go. It will however give a single chirp if the start button is pushed. This intermittent problem has, as I said gone on for years.

The machine is at the dealer now and they are down to wanting to replace the MPEM ($$), which are back ordered until into Aug.

If you or anyone on this forum comes up with a solution, I will be very interested to hear it. Thanks.:bigear:
 
trashtosser said:
Mrlmd1,
I too am having a similar problem, for years now actually. Mine is a '98 GTS with the 717/720 engine. Mine too will recognize the key with the familiar "chirp-chirp", then a some time later, no go. It will however give a single chirp if the start button is pushed. This intermittent problem has, as I said gone on for years.

The machine is at the dealer now and they are down to wanting to replace the MPEM ($$), which are back ordered until into Aug.

If you or anyone on this forum comes up with a solution, I will be very interested to hear it. Thanks.:bigear:
Click to expand...

Dude, go get ur ski. It aint the 600 dollar mpem.
 
as mentioned above, if/when the dess post goes bad/goin bad, it'll not recognize the landyard, giving 1 beep, and other times, what you experience, it does work, and off you go.
 
My problem maybe could be the DESS post. Is there a way to test that to see if it's good?
But when I put the key on the post I get one red light flash on the dash, so doesn't that mean the post is working, as at least it recognizes a key is on?
If I hit the start button 5 times, I only get one red light on the first hit. Does that mean the MPEM is bad? Or should I get light flash each time I hit it?
And Seadooya, I did find the red wire in the rear electrical box attached to the main battery post from the fuse holder on the starter solenoid, and I did clean up and tighten again that contact. And that fuse is good.
Maybe a trip to the dealer to see if my keys and the MPEM are still programmed correctly, if they would check that without charging me $130 for a "diagnostic check" that they wanted to find my problem.
 
yeah, i hear ya. Had a key programmed for mine, cost was a 12 pack. Took, no sh&*, not even a minute, to program. I held up the process, cuz the lil black wire wasnt hooked up....
 
I tested the DESS post and all connections are made correctly when you attach the lanyards, so the magnets and the contacts are all good.
There is some corrosion that I tried to clean off inside the 15 amp fuse holder in the rear electrical box, Could that be preventing the MPEM from getting power? I could try and jump that and see if it works.
I have a hard time thinking the MPEM is toast (no fuses have blown and it's never been overcharged) and don't want to dig into it to replace a diode if it's not necessary. Because the diagnostic mode doesn't work does that mean the MPEM is not getting juice or that it's history?

By the way, all my 3 lanyards measure 2 ohms, so they are all the same. Is that the value my MPEM is looking for to make the handshake?

A different question for a moment - I want to remove the cover on the handlebars over the starter button to replace it, as the rubber covering over the button is starting to dry out and will crack soon, and replace the buzzer which is not working. Does anyone know the size of the small Allen head screw under the handlebar cover? I seem to have Metric Allen wrenches which don't fit, I guess there are SAE sizes too?

Edit to post - There's no voltage drop across the 15 A fuse holder in the rear compartment so I guess that's not the reason the MPEM's not getting power.
So I give up, just hope there's some other thing I can do without opening it up.
 
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I got a wiring diagram and have 12 v entering into post 26 on the connector plug to the MPEM from the RE-PU wire coming from the rear electrical box, so all connections up to the MPEM are clean and intact and it gets power delivered to it.
I tried to measure continuity to ground from post 25 on the MPEM itself and on the BK wire post 25 coming from the rectifier/regulator, but there is none there in either of them. But I could measure continuity to ground at the BK wire from the MPEM leading to the DESS post in the connector to the DESS post, so there must be a ground connection to/in the MPEM, right?
(You may need to have access to a wiring diagram to see what I am talking about).
So, if the power to, and the ground, is OK, even though no fuses have blown, does that convincingly mean my MPEM is bad and I should cut it open and replace the diode? If I cannot get it to enter the diagnostic mode with 5 presses of the start button, and it is getting power to it, does that mean it's bad?
My battery at present is reading 12.3v, I know it's low and needs to be replaced, but (last question I hope somebody can answer) is there a minimum voltage these things will respond to ? There was no difference with a 12.6 v battery jumping it, or does it need more power to get it to work?
 
My problem still exists and it's making me nuts.
With a good 12.6 v battery attached, it makes no difference, still only 1 light on the dash when I press the start button or 30 sec later if I attach the lanyard to the DESS post. Again, testing the DESS post with key off and on reveals it to be good. It will not enter diagnostic mode with 5 presses of the start button. All fuses are good.
I have power to the MPEM at terminal 26 from the connector, and I have power out of the MPEM at the red wire coming from terminal 24 leading to the rectifier. Can the MPEM still be toast if there's power coming out of it like that or is that unrelated?
Is there any test a dealer can do to test the MPEM aside from selling me another one and putting it in and see if it works?
If the coil or starter relay was bad, I wouldn't think that should have any effect on the MPEM function, but what do I know? The MPEM should still handshake with the lanyard, right?
I have checked every single connection and all seem clean and don't know where to look. My buzzer doesn't work and has not worked for a while but the ski ran absolutely fine before just sitting idle for 65 months.
I hope someone can answer me.
 
After I replaced my buzzer with one from Radio Shack for $3.49, I got the 2 beeps when attaching the lanyard to the DESS post, and it appropriately enters the diagnostic mode with 5 clicks of the starter button, (the MPEM is fine), and testing everything else, I determined the problem was a bad starter solenoid. So after replacing that (ordered online), my ski is back in service and works fine.
My only current problem is that I cannot get the baffle out to replace my fuel lines and the float in the baffle (so my gas gauge works), despite moving the gas tank forward. I cannot get to the bolts to remove the steering head to get the extra room needed to pull out the baffle. I removed and cleaned out my carb fuel filter (only 10-15% clogged with gook) and put another inline fuel filter in just before the carb so I don't have to do that again. Hopefully this will keep me going and until it starts to bog down, I won't try to disassemble it again. I'll just check the fuel tank visually from time to time and keep track of the hours used to estimate what's left in the tank.
 
Besides the pre-ride check of opening the seat to LOOK=FEEL=Smell for gas or vapor
leaks in the engine compartment, Open the front hatch, remove basket, remove the
cap from the water separator/filter and note water-discard any trash. A water
droplet in the carb can shut down a Seadoo!
 
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