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How to I know If I Have a MPEM or ECU Failure?

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seadooman55

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hello to all! I have been talking to Dennis on this topic but i didn't know any of you had any similar issues. It looks like the previous owner of my ski had jumped started it with his car in which it fried the ECU(so we have concluded) and shorted 2 of the coils (2 and 3). I am only getting spark to pto cylinder. the other 2 aren't getting spark but have 12v to them and all the injectors work normally. I just want to make sure it's the ECU and not the MPEM unit. I am waiting on a service manual now but i figured if any of you have had this problem before it would save me trouble and aggravation in buying an ECU and that not being the problem. Thank you!
 
Mpem

I am having the same issue with my Speedster 150.

My friend used the boat and the batt was dead so he tried to jump start it with his jeep....

now when i put the lanyard on the post the boat doesnt even beep, it lights up the dash for about 2 seconds and then goes dim again... i can hear the fuel pump engage... and then nothing..

new battery...

i checked all the fuses and i had 2 fuses blown in the back, a 5amp and a 3amp.. the 5amp had been very corroded also...

i also had a few blown in the dash... but i think those were blown from a while ago, my bildge and my blower...

anyway i replaced the fuses and still same problem...

i am guessing i need a new mpem or whatever, or maybe that guy is still around that fixes them?

any information would be really helpful, thank you!:cheers:
 
there is a 10A fuse that powers each cylinder and injector, check that, i found mine blown and that is how i could tell the coils shorted out. Check to make sure your coils aren't getting warm that means there staying grounded and that will fry them (as i found out) i narrowed it down to 2 things, eather the ECU(because im not getting spark) or the MPEM because nothing is beeping but all the display items work. I'm waiting for the new coils and my service manual then i will be able to maybe trouble shoot it if not im going to take it to the dealer and see what they think. I'll keep ya posted.
 
mpem

Hey thanks for your reply! i am dieing here...

so you say if the display panel WORKS - then the mpem is okay?? my display panel lights up for a second when you put the lanyard on the post but then it goes dim in like 2 seconds, so i am not able to see how much gas is in it or anything.. i get nothing... i dont even get lights or music from my radio....

i am thinking maybe a grounding issue?
 
i found this while digging for answers, maybe it will help you.... some repair manual for seadoo watercrafts...
________________________________

Causes of troubles are not necessarily related to
starter but may be due to a burnt fuse, faulty battery,
start/stop switch, safety lanyard switch,
MPEM, solenoid, electrical cables or connections.
Check these components before removing starter.
Consult also the starting system troubleshooting
table on next page for a general view of
possible problems

Basic Self-Diagnostic Mode
It is self-activated when the safety lanyard is being installed on the watercraft switch. It gives immediate
monitoring. Some codes may occur only when pressing the start/stop button. Refer to the following
chart.
SIGNAL
2 short beeps
(while installing
safety lanyard on
watercraft switch)
CAUSE
• Safety lanyard is
recognized by the MPEM.
REMEDY
• Ignition is authorized, engine can start.

SIGNAL
1 long beep
(while installing
safety lanyard on
watercraft switch or
when pressing
start/stop button in
some cases)
CAUSE
• Bad connection between
safety lanyard cap and
switch.
REMEDY
• Remove and replace the safety lanyard on the
switch until 2 short beeps are heard to indicate
the system is ready to allow engine starting.
• Unprogrammed or
defective safety lanyard.
• Use the safety lanyard that has been programmed
for the watercraft. If it does not work, check
safety lanyard condition with the programmer.
Replace safety lanyard if reported defective. If it
still does not work, enable more detail about the
failure.
• Salt water in safety
lanyard cap.
• Clean safety lanyard cap to remove salt water.
• Improper operation of
MPEM or defective wiring
harness.
• Enable advanced diagnostic mode to obtain more
detail about the failure.

SIGNAL
8 short beeps
CAUSE
• Defective MPEM
(memory).
REMEDY
• Replace MPEM.

SIGNAL
Continuous beep
CAUSE
• Engine overheating.
REMEDY
• Refer to TROUBLESHOOTING 02-01.

MPEM
If 2 short beeps are not heard when installing the
safety lanyard, refer to ELECTRICAL SYSTEM 07-06.
Engine Start/Stop Switch
Switch condition can be checked with an ohmmeter.
Disconnect the switch YELLOW/RED wire. Connect
test probes to YELLOW/RED wire and to
ground near solenoid.
Measure resistance, it must be an open circuit
(switch is normally open). Depress and hold
switch, the ohmmeter should read close to
0 ohm.
Safety Lanyard Switch
The following continuity tests can be performed
using an ohmmeter:
Disconnect switch wires.
Safety Lanyard Removed
Connect test probes to switch BLACK and
BLACK/YELLOW wires. Measure resistance,
there should be no continuity (open circuit).
Connect one test probe to the WHITE/GRAY wire
and the other test probe to the switch terminal.
Measure resistance, it must be close to 0 ohm.
Connect one test probe to the BLACK wire and
the other test probe to the switch ring. Measure
resistance, it must be close to 0 ohm.
Safety Lanyard on Switch
Connect test probes to switch BLACK and
BLACK/YELLOW wires. Measure resistance, it
must be close to 0 ohm.
Solenoid
NOTE: Solenoid is located in the electrical box.
Inspect connections and clean as necessary.
Static Test: Continuity
With a multimeter, check primary winding resistance.
It should be approximately 5 ohms.
There should be no continuity between the positive
posts of the solenoid.
Dynamic Test
Depress start/stop button and measure the voltage
on the solenoid positive posts with a multimeter.
If there is no voltage and battery is in good condition,
replace the solenoid.
Electrical Cables or Connections
Check all connections, cables and wires. Tighten
any loose cables. Replace any chafed wires.
hotolds442 is offline Reply With Quote

----------------

It also came with some advice and something to try to check the mpem..

-----------------

originally posted by: hotolds442

OK, one more check...... There are 6 fuses inside the electrical box, pull all of them and visually check for dead fuses. The top 3 are spares for the bottom 3. The fourth one from the top is the VTS fuse, it should be a 7.5 amp, the next one is a 5 amp fuse - EXAMINE THIS ONE CLOSELY it is the fuse for the mpem. the bottom fuse is a 15 amp fuse - it is for the battery. I didn't recall seeing anything above about the fuses so check these next and we'll go from there.


Just noticed in the post above that you checked the fuses, so the next thing to do is to follow the wiring step by step.

1) Disconnect the yellow/red and black wire from the start/stop switch. You should find this under the glove box. Connect a short piece of wire between the two wires that lead to the electrical box after connecting the lanyard. You're looking for any sign of life here.

Reconnect the wires if no life forms exist.

I assume that the ohmmeter was used to verify that the start/stop was functional, if so, proceed.

2) Disconnect the Purple/tan and tan/black wires from their conector, again under the glovebox. Connect an ANALOG voltmeter across the two connectors leading to the electrical box. Connect the lanyard. You're looking for any needle movement. Needle movement will indicate that a signal is being sent to the buzzer, but the buzzer is not working. (we already knew this, but we need to see if the mpem is sending a signal)


3) Remove the lanyard, but keep the meter hooked up. Press the start button 5 times and again look for deflection of the needle. You should see the needle move,pause, and return, and move and return (one long and one short beep)

4) Install the lanyard again and press the start button, again looking for deflection of the needle - write down what you see in this step

If the needle deflects on any of these steps, let me know. If not, you're most likely in need of an mpem.
 
hey thanks for the info!! i will check that out tonight. That is a better way of testing the beeper then what i had in mind and that is a good way of testing the MPEM unit aswell. I am getting power to my starter it cranks over and all my guages work fine no dimming so this makes it less convincing that it is the MPEM. The MPEM is the supporting system for the DESS system and to provide power to your systems. I have power to everything but the beeper it seems. That is why i think it is my ECU but who knows electrical syetems in these SUCK!! I will keep you posted on what else i find. THANKS!!!
 
i took mine to the dealer and they diagnosed mine. Turns out it was a bad ECM. They did it for $100 bucks rather then me scratching my ** for hours on end...hope that helps!
 
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