Yet Another DESS Key Post

[quadridermx]

Hello everyone. Long time lurker, first time poster. I bought an 01' XP that won't start. The owner gave me what he said were the correct keys. Was hoping someone could help me! My issue is similar to other, but with one small twist that I couldn't find info on.

Here's what I have so far... known good battery, motor will turn over great with a shorted solenoid.

-Put the DESS key on, press start button, one long beep. I know this means either a mismatched key or failure to communicate with the MPEM.

-Without the lanyard on, press the start button, gauges work for 33 seconds and turn off as they should. VTS also works.

-Take lanyard off, press start button 5 times, one short / one long beep. Goes into diagnostic mode fine. Put the lanyard back on, nothing at all. Does this mean there are no error codes?

I assume the DESS post is fine since it works for everything else aside from actually getting the two correct beeps when I put it on. Is that correct?

I'm leaning toward the ROM chips in the two DESS keys I got being bad. Is there any way to test the ROM chips? Obviously the magnet is just fine.


Any help is so much appreciated! Thanks!!

 

[Strizzo]

in diagnostic mode, when you put the lanyard on and get nothing, hit the start button, what do you get then? i get two beeps like i just put the key on when i hit the start button after putting the key on in diag mode. if i try to start again i get a long beep like the MPEM has gone to sleep. pull the key off and put it back on and i get two beeps and it starts.

 

[Dr Honda]

Yep... what he said. You have to push the button one more time, after putting the lanyard on.


It sounds like your post is fine, and the MPEM just isn't reading the lanyard. Call your local dealer, and ask them to re-program the lanyards.

 

[quadridermx]

I see... Thank you. When I hit the start button 5 times, get the short and long beep, put the lanyard on, and THEN hit the start button again, it gives me one long angry beep.

Is it safe to say the MPEM is most likely good? Just need to be reprogrammed?

I ask because I figure it'll be at least $100 for a new DESS key and programming from the dealer. I can get a used MPEM with lanyard for around $300. As anyone else does, I really hate wasting $100 at a dealer! Is there any further troubleshooting I can do to make sure the MPEM is good?

Thank you!!!

 

[Seadoobuddy]

Send it to Nick (minnetonka4me) For $20 he will check the MPEM and he can program your key to match the MPEM probably for additional charge of a few bucks...ask him his price.

 

[tshaw]

I thought for sure my mpem was bad I did as suggested sent to nick found out it was fine got the hours from it. I ended up getting a key and had it programmed for a fraction of what my dealer charges with no hassle

 

[quadridermx]

Update:

Took it to a dealer and their MPEM programmer couldn't even connect to the MPEM on my XP. He was able to test the keys, and they checked out OK.

I know I have power to the MPEM. 12.48v.

I think I tested the dess post. Disconnected the plug in the steering column. With lanyard off, it's open between black and black/yellow. With lanyard on, it's shorted between black/yellow. Are there any resistance measurements I can try between gray/white and black or black/yellow? I can't find any posts on that.

Also, are there any further tests I can do with the MPEM? Everything I've seen so far points to it being OK, but I know they can be very misleading.


Thank you so much for your help! I also sent minnetonka4me a message, but haven't heard back from him yet.

 

[Sportster-2001-951C-Stock]

"their MPEM programmer couldn't even connect to the MPEM on my XP. He was able to test the keys, and they checked out OK."

In that case, I don't understand how he could program the MPEM to accept the good keys? Just because the keys are good doesn't mean the MPEM recognizes them as valid, right?

My understanding is, your MPEM needs to be programmed to accept the keys as valid, no?

 

[quadridermx]

That is correct. He said the programmer recognized the key (lanyard) right away, when it was off the post. His programmer had a plug on it that he put the key on.

However, he wasn't able to program the MPEM with his programmer because it wouldn't even establish communication with the MPEM (through the DESS post on the ski, of course)

 

[quadridermx]

Another interesting side note... My spare fuses both have 12.5v to them. Is that normal?

 

[Sportster-2001-951C-Stock]

"My spare fuses both have 12.5v to them."

LOL, no kidding! Must be to keep them factory fresh?

 

[quadridermx]

No kidding. Haha, is that normal? I wouldn't think a spare would have any power to it...

I did verify that it is the correct part number MPEM.

 

[Sportster-2001-951C-Stock]

Yes, I would expect 12V on spares is normal. I bet there's no current flow though. Probably the metallic contacts soldered to the + buss bar are the only thing that keeps those fuses from falling into the bilge when the cover is removed.

As far as the DESS goes, sounds like the only item remaining in question is the post and associated wiring