No start- Long beep w/ check engine light

[Floridan surfer]

The title pretty much sums it up.

When I plug in my key, I get a long beep, followed by the four short beeps and the check engine light is on. I brought it to a watercraft mechanic who read the codes and advised me that I have a code for DESS post.-Sorry I didn't get the exact code. He suggested that I start by replacing the DESS post, but also advised that it could be the computer or the wiring harness. He did Mention that the computer was doing funny things and at one point, indicated that it looked like it was going bad. It was having trouble communicating with the candoopro.

I have pulled the post and tested it using the following procedure I found on another forum:

++++++++++++++++++++++++++++++++++
DESS Post test
++++++++++++++++++++++++++++++++++

You can test the DESS Post itself with an Ohm Meter and the following procedure:

Check the DESS Post physical connections first.

With the Lanyard off and using the Ohm Meter on the Black Packard connector wires:

Blk wire to Blk/Yellow = Open Circuit
White/Gray wire to terminal on post = 0 Ohm (.7~1.3 Ohms found=OK)
Blk to ring of post = close to 0 Ohm (.6~5.2 Ohms found=OK)

Lanyard on...

Blk to Blk/Yellow = close to 0 Ohm (.6~5.3 Ohms found=OK)

It tested fine. I should also mention that when I plug in the key I can hear the fuel pump kick on which tells me that the reed switches are working.

So then I tried to test the key itself with a ohmmeter. I figured that if the key makes the connection between the button and the ring on the DESS post, I should get some kind of a value on the key itself when I put my test probes on the center metal strip and the metal strips on the wall. The key was open between these two points. Does anyone know if there should be continuity between the two metal strips on the key?

Unfortunately, I do not have a spare key for the boat for testing.I do have another key that is not programmed for the boat and if I plug it in, I get the same exact thing - Long Beep with a check engine light.

Initially I thought the key/computer lost its program, but the mechanic indicated that my key was already programmed to the computer and he also programmed the additional key to the computer. He states that he does not know if the computer accepted the additional key or not due to the communication issues.

Can anyone offer any further guidance for testing before I start throwing money into replacement parts?

 

[Sportster-2001-951C-Stock]

So then I tried to test the key itself with a ohmmeter. I figured that if the key makes the connection between the button and the ring on the DESS post, I should get some kind of a value on the key itself when I put my test probes on the center metal strip and the metal strips on the wall. The key was open between these two points. Does anyone know if there should be continuity between the two metal strips on the key?

I guess you have a copy of the 4-tec shop service manual and have already run through the DESS troubleshooting procedure?

I think you will not measure continuity of the DESS key this way, there is a coded chip in the key that is read serially by the MPEM, it's not simple resistive button or element.

I highly suspect a harness connector or ground terminal somewhere is the root cause, making partial contact. I normally use silicone based spark plug boot grease on the sealing gasket of this type of harness connector in an attempt to avoid water penetration and corrosion.

You're getting closer, I can feel it!

 

[Floridan surfer]

I guess you have a copy of the 4-tec shop service manual and have already run through the DESS troubleshooting procedure?

No, I do not have the shop manual. I guess I need it. Any suggestions on where to get one?

 

[Sportster-2001-951C-Stock]

I found my BRP factory service manual on seadoomanuals dot com but a google search might reveal other sources as well. I think if you join the members and submit a small fee at the top of this page you can download manuals there as well.

I don't think you'll locate a manual for a boat though, the manual I use was published for skis and the powerplant is identical in most ways so it's adequate for my purposes. Electrical schematic and harness are almost exactly the same as well as mechanical aspects. Basic difference is hubcaps and decals from skis won't fit our boats.

 

[Floridan surfer]

Okay gentlemen, I could use some help with wiring diagrams/continuity test.

I am trying to check continuity from the white/gray striped (DESS signal) wire from the DESS post harness to the ECM.


I did what sportster 2001 suggested and had a look at a wiring diagram. This wiring diagram was for a JetSki though. On this diagram (if I'm reading it correctly), it shows that the white/gray DESS signal wire goes from the harness directly into pin B-38 of the ECM.

I have since purchased a O6 challenger 180 specific wiring diagram. This diagram is a little bit different from the JetSki diagram. It appears to show that the DESS signal wire goes through the VCM (vehicle control module; the fuse block next to your feet) on the Challenger, and then continues to pin B-38 on the ECM.

I am not getting any continuity on the white/gray stripe wire from the DESS post harness to pin B-38 on the ECM.

Is there someone here who can verify:

1. That I am reading the wiring diagram correct and ECM pin B-38 is the DESS signal from the post harness?

2. With the harnesses unplugged, should I be getting continuity? Is it possible that the DESS wire is switched at the VCM?

Any help would be greatly appreciated. I'm about at my wits end with this boat.

 

[Floridan surfer]

Is there someone here who can verify:

1. That I am reading the wiring diagram correct and ECM pin B-38 is the DESS signal from the post harness?

2. With the harnesses unplugged, should I be getting continuity? Is it possible that the DESS wire is switched at the VCM?

Thanks for the overwhelming responses (sarcasm). I guess if nothing else I'm logging my troubleshooting progress and maybe this can help someone in the future.

I conducted a couple of continuity tests. I've confirmed that "yes" is the answer to my question number 1 above.

I think the VCM (fuse box by your feet) is the problem. All continuity tests are as they should be with the signal wire, until I plug it into the VCM. I remove the VCM and tested continuity on the two pins for the signal wire (which are A-28 and A-21 on the VCM). I have no continuity through the VCM.The pins for the ground wire and switch wire do have continuity through the VCM.

So here's my current question - I need some opinions before I go cutting my wire harness:

Rather than spending over $500 to replace the VCM, I'm thinking of just bypassing the DESS signal wire junction at the VCM. It would just be a matter of cutting the white/gray wires at the harness and connecting them together. Keep in mind,The Jetskis do not even have a VCM-the signal wire just goes straight from the post harness to the computer, which is essentially what I would be doing. Does that sound like a good plan?

 

[Sportster-2001-951C-Stock]

Would if I could, and not b/c I choose not to but b/c I have no info.

On my boat there is no VCM and have no idea what the purpose of the VCM is on yours.

Here's the schematic of my boat, I'm sure you can see from this it's not the same or close enough to fudge an educated guess to resolve the issue you're struggling with:

 

[Floridan surfer]

Ok, so a new (used) ECU fixed the boat. This boat is now on it's 3rd ECU. Time for a craigslist ad. I'm done with Seadoo. Hopefully this'll be my last post on this forum.

Good luck everyone...

 

[Coastiejoe]

I'm betting you have a poor connection. Ground or corrosion somewhere causing the MPEMs to fail.


Sent from my iPhone using Tapatalk

 

[Sportster-2001-951C-Stock]

Glad you got it going, sorry the ECU took a dump? Thought you had a wiring diagram though, and concluded the DESS signal was lost on it's way to the ECU?

 

[Floridan surfer]

Glad you got it going, sorry the ECU took a dump? Thought you had a wiring diagram though, and concluded the DESS signal was lost on it's way to the ECU?

I did... And that part I don't understand. My guess is that the DESS signal wire gets switched through the VCM (fuse block at your feet) which is really weird.

 

[Sportster-2001-951C-Stock]

Okay, thanks for the detail. Repeated failures are no fun, that gets old quickly. All I can think of is to check the system voltage at the battery and make sure it's not too high or suspect some aftermarket additions if there are any.

Good luck with it though or if you decided on something else, perhaps it's time for something more bulletproof.

 

[pete63]

just went though your other posts, on other forums there are posts of strange things happen when there is a short or open wire some where on the ecu wiring harness.
just thinking about your previous problems, the ics, rectifier and bilge pump, might be worth re checking all connectors for an open or short wire back to the ecu, or did that rectifier problem caused the ecu problem?

re-posting from another forum
>With a DMM, measure the resistance from the outer ring of the DESS post, to the center button. Report back what you get.
>A short between these two points will throw this fault.
CHECKED, no short.

>If no short, then it is possible that there is an open wire between the center button of the DESS post and the pin on the ECU.
Which pin number? B38?

the center pin of the dess post passes through the VCM and goes to the ECU B-38. So you can ohm the connection between B-38 and the Center pin on the DESS post.

 

[Floridan surfer]

re-posting from another forum
>With a DMM, measure the resistance from the outer ring of the DESS post, to the center button. Report back what you get.
>A short between these two points will throw this fault.
CHECKED, no short.

>If no short, then it is possible that there is an open wire between the center button of the DESS post and the pin on the ECU.
Which pin number? B38?

the center pin of the dess post passes through the VCM and goes to the ECU B-38. So you can ohm the connection between B-38 and the Center pin on the DESS post.

What forum is this from? I'd like to read up on this. Wish I would've saw this when I was troubleshooting.

 

[pete63]

candoo forum......


his problem sounds a little different but could be similar, that's why its important to know what fault codes are active or occurred.
the other part was posted here.
http://www.seadooforum.com/showthre...ss-key-service&p=434715&viewfull=1#post434715


any chance the rectifier faulted the ecu?