Need DESS help - 1996 GTi

[kevinz]

I have a problem with the DESS system on my 96 GTi. The previous owner said the ski needed a new key when I bought it. I was trying to confirm this today. Here is what appears to be happening:

When I put the lanyard on the DESS post, no beeps. When I push the start/stop button, I get one solid beep. The gauges also come on. I took the lanyard off and pressed the start/stop button 5 times and heard the beeps to put it in diagnostic mode. The gauges came on. I put the lanyard back on the post, and no beeps. I pushed the start/stop button, and I heard two very short beeps and the gauges shut off.

This is a freshwater ski and all the connections in the e-box look very good and clean. The fuses on the MPEM aren't blown. I can crank the engine if I jump the solenoid terminals, and it cranks just fine.

The battery is a brand-new AGM type powersports battery.

Does it sound like I need a new key, or is my DESS post shot? I get conflicting answers about exactly what the beeps mean when I search online.

Thanks!

 

[Waterluvr]

Sounds like your MPEM is working as it should, it simply does not recognize the key you're trying to use as it not's programmed to memory. Easy enough to double check when your service provider hooks up with Buds or Candoo they can read the numerical code in the key chip and compare it to what's stored in the MPEM memory and add it if needed.

Here's what stored key codes look like in a module, this unit has 4 keys programmed to it:

On Edit:
If you want to test your DESS post you should have an open circuit between the black & black w/yellow trace wire on the back side of the post, that circuit should close and show less than .5 ohms when the key is on the post. Probe the white wire and test from there to the small center contact on top of the dess post you should have continuity there as well.

 

[kevinz]

OK thank you for the information. I figured that was the most likely scenario. I figured that if the MPEM is getting signal from the key post, then the wiring must be OK if the MPEM is able to beep and activate the gauges as it does. However, just to be safe (and to give me something to do LOL) I did a continuity check on the DESS key post according to info I found online. Here is what I did, what the specs should be, and what they actually are.

Lanyard off
black and black/yellow: open (showed open)
White/grey to switch terminal: 0 Ohms (showed 0 ohms)
Black to switch ring: 0 Ohms (showed .2 ohms)

Lanyard on
Black and black/yellow: 0 Ohms (Showed .3 ohms)

If any of those are suspect, I'll try to track down a good DESS post. I didn't do the start/stop switch test since the ski beeps when I press it, so that tells me (I hope) that it is OK.

Thanks!

 

[Waterluvr]

No worries there that's all within spec, sometimes it doesn't hurt to probe the post wiring all the way back at the module just to rule out something along the length of the harness but aside from that your module needs looking into from there.

 

[kevinz]

OK, I'll get in touch with the board member here who does key programming (he has posted in another thread of mine) and see what we can do, thanks!

 

[kevinz]

OK, so I figured I would throw an update up here. It seems that my issue is a bit stranger than what most deal with. After sending my MPEM and key in for programming, it did the same thing when I got it back today and put it in the ski. After a couple hours or so on the horn with [MENTION=71806]Waterluvr[/MENTION] going over and doing some diagnosis, it appears that my MPEM is bad despite bench testing OK. The module powers on and has everything it needs to work. However, when we run a jumper wire from the black/yellow wire that comes from the DESS post to the MPEM directly to the negative battery terminal, and another jumper wire from the white/grey wire coming out of the MPEM directly to the key, no workie. We basically took the post out of the equation 100% and it still doesn't work.

So at this point, it looks like my MPEM has a very weird failure issue and I need a new one. But I can't say enough kind words about [MENTION=71806]Waterluvr[/MENTION] for taking the time to hook me up with all of this and get me going on the right track.

 

[Waterluvr]

You're still the luckiest guy in the world, your module and it's ability to accept / store programming inputs are good and all the history is still there from day one. I'll let you share the data screens if you care to, can't get over how low hours that engine has on it man what a find that was.

That's probably the best deal I've seen anybody grab on here yet, and you are in the company of professional bargain hunter's here that can smell a deal on Craigslist .002 seconds after it hits the internet.

 

[kevinz]

Eh I tried, but my computer-fu is weak LOL. But it's nice to know it only has 108 hours on it...but still bugs me that the MPEM took a crap!

 

[Waterluvr]

Anytime you want to post pics in a thread, just host it at like photobucket or tinypic and you can direct link to it.

 

[kevinz]

I will keep that in mind, thanks