Launch issues Seadoo 720 1999

[arsenic]

Hello everybody

My name is Rémi, I'm French.

I have buy a Seadoo 720 year 1999 and I have an issue.

The jetski don't start.

I put the Key and I ear 1 short beep and 1 longer.

The batterie is new and the starter is new too...

When i push START button there is nothing... no sound, no "clac", nothing at all...

I'm searching a solution to solve this problem

Thank you very much for yout help and sorry for my school english

 

[SIMPLEARKANSAN]

Codes for 1996 XP. May be the same. Not completely sure.

Monitoring Beeper Coded Signals
NUMBER OF BEEPS POSSIBLE CAUSE REMEDY

2 short (while installing safety
lanyard on DESS post).
• Everything is correct with the
safety lanyard (good contact
and right lanyard cap).
• Engine can be started
normally.

1 long (while installing safety
lanyard on DESS post or when
pressing start/stop button in
some cases).
• Bad connection between
safety lanyard cap and DESS
post.
• Remove and reinstall the
safety lanyard on the DESS
post. Two short beeps
should be heard which
indicates the system is ready
again to allow engine
starting.

• Wrong safety lanyard. • Use the safety lanyard that
has been programmed for
the boat. If it does not work,
refer to an authorized dealer.

• Salt water in safety lanyard
cap.
• Clean safety lanyard cap with
fresh water to remove salt
water.

• Improper operation of
MPEM or defective wiring
harness.
• Refer to an authorized dealer.

4 short (while pressing
start/stop button with safety
lanyard already installed).
• Shifter is NOT in neutral. • Place shifter in neutral. While
moving the shifter, 1 short
beep indicates you reached
the neutral position.

1 short (while moving shifter
to neutral).
• Confirmation that shifter is
now in neutral.
• Engine is now ready to be
started

8 short. • Defective MPEM (memory). • Refer to an authorized dealer.

Continuous. • Engine overheating. • Refer to Engine Overheats
below.

 

[etemplet]

From what I am reading, you may have a problem with the key/lanyard. I don't see any diagnostics that specify one short and one long in that order. In advanced diagnostics which you are probably not entering that mode, there is a one long and one short beep and it means that a Lanyard has not been programmed for that MPEM.

I would check communication issues with the Lanyard and the MPEM. Here is how to enter the ADVANCED Diagnostic Mode.

Remove the safety lanyard cap from the switch
Press the Start/Stop button 5 times
(one short beep and one long beep must be heard) - they verify the ski is in the advanced mode
Install the safety lanyard on the switch
press the start/stop button again.

The number of beeps will correspond to causes or problems with the ski.

 

[arsenic]

Thanks for the help !

Thank you for explaining to me how to enter the advanced diagnostic mode !

I'm going to try this week-end and I'll be back

 

[GGuillot]

Per the SM guidelines, with a DMM, run a continuity test on the DESS post. Test it at connections all the way through to the MPEM. Rule that out first...

Test the lanyard cap itself, it tends to be unreliable above 10 ohms. I've tested old ones as high as 20 ohms that still worked with my MPEM. Brand new DESS lanyards I've tested will show 6 ohms or less. Select 'resistance' with the DMM and touch the center and side contacts in the lanyard cap.

Ck all fuses...

If you just bought the jet ski are you sure the DESS key you have was previously programmed to the MPEM?

 

[NickCawks]

A bit off topic but doesnt the 1999 xp have a 951 in it?

 

[GGuillot]

A bit off topic but doesnt the 1999 xp have a 951 in it?

Yes, but in the original post he never mentions it's an XP.

 

[etemplet]

This is probably a GTI or GTS.

 

[arsenic]

Hello, yeah it's a GTI. It's exactly this :



I buy it knowing that he have an electric issue.

Thanks for the test procedure

I will test and clean all the electrical sheaths with a DMM and a toothbrush and WD40 this week-end and check all fuses

THANK YOU VERY MUCH FOR YOUR HELP

 

[NickCawks]

Dunno why I thought I saw xp. :/

 

[etemplet]

Dunno why I thought I saw xp. :/

You saw simplearkansan's post test procedure for the 96 XP. Maybe.

 

[etemplet]

Regarding cleaning the connectors. On the MPEM there are 3 wide connectors on the bottom of one of the large plugs. They are wide not round. I would suggest pulling the plugs and looking for those and clean them. When I had no start issues on a ski those connectors were oxidized. That is one of the first things I check. You should download a shop manual to help you troubleshoot. Good luck !! Post your findings.

 

[arsenic]

Thanks I have download a shop manual for 1999 Seadoo models (in English lool)

I will check the MPEM connections first

I'll tell you if I solved my problem and how I was able to solve it

 

[etemplet]

When you get the problem solved you have to post this picture in the thread.

 

[arsenic]

Hi all,

I'll tell you about the rest, for now I was waiting for the pay to buy a new battery, it's done I ordered it
As on the technical documentation I took the recommended one (12v 19A.h Yuasa)

I will check its voltage and charge it with my smart charger if necessary

Once in place I will make sure that there isn't noise like "clic" (if I hear clicks from the starter relay or elsewhere)

I would like to rule out a malfunction of the START / STOP switch, I have seen on the electrical diagram that it will be necessary to be touched the Yellow-red and black wires of the contactor to start the engine.

I will keep you informed of the rest

Thanks

 

[benjilafouine]

Long beep would be key not recognized. Could be a DESS post issue. Usually it starts intermittently then in the end no more beep at all. Also, the engine can stall suddenly with a bad post. It is not hard to replace.

 

[arsenic]

Thanks for the answer, I just do a small video to help you to understand my problem

 

[benjilafouine]

Sorry for writing in French...

Je crois que la première étape serait de changer le terminal DESS. Quand le terminal se met à mal fonctionner, il devient très difficile de faire un diagnostic. Cela peut aussi être la clé elle-même. Vérifier pour la présence de mâchefer en-dedans et nettoyer. Aussi, si une deuxième clé cause le même problème, la première étape est de remplacer le DESS post.

Si le remplacement ne règle pas le problème et que deux clés causent le même problème, alors je commencerais à suspecter le MPEM.

Si vous ne possédez pas de deuxième clé, le diagnostic devient plus compliqué mais entre un DESS et une nouvelle clé, il est plus facile de changer le terminal plutôt que la clé surtout si aucun concessionnaire n’est présent dans votre région.

 

[GGuillot]

You only know what you know when you buy a used ski that you haven't seen run. I'd question whether the DESS lanyard you have is actually programmed to the MPEM in the ski. A seller can do some sketchy stuff when making the sale. You wouldn't be the first person to buy a ski where the lanyard isn't programmed to the MPEM.

You could try replacing the DESS post first, but there's procedures how to check it in the service manual so it might be good. I had a similar problem like you show in the video, my issue was a bad MPEM. If you've done everything you can do with the DESS post being good, and you know for sure the lanyard key is good and programmed to the MPEM, then the MPEM being bad is the last thing..

I'd send the MPEM and the DESS lanyard to someone and have it checked.

 

[benjilafouine]

I tried this procedure on my 2003 GTI and the problem with these DESS posts is that they’re acting intermittently are first with inconclusive results. As I wrote in French, if no dealer is around and that only one key is available, maybe replacing the DESS post first is the best course of action.

 

[arsenic]

Hi, thank you benjilafouine and GGuillot for your answers

I cleaned the DESS terminal and the two keys.

Before changing the DESS terminal can I test it with the multimeter?

I hope the seller did not lie to me about programming the keys, it would be much more annoying.

I also forgot to test the resistance of the keys.

I'm going to be interested in changing the DESS terminal, I will make you a new video

 

[GGuillot]

Before changing the DESS terminal can I test it with the multimeter?

Yes, download the service manual for your ski/yr SeaDoo Manuals - FREE PDF Download! if you haven't already, which will describe the test procedure for testing the DESS post for continuity.

I also forgot to test the resistance of the keys.

Put the multi meter on resistance or ohms, if the keys are new you should see 6-7 ohms or less, old keys can read as high as 20 ohms. Word is that over 10 ohms they become intermittent or unreliable.

 

[arsenic]

Hello,

Thanks my friend
I have tested the key, they are good
It's probably a DESS post issue so I'm going to buy a new.

Have you a good website to order a new?

This is my key test video

 

[mikidymac]

OSD seadoo sells them. Or if you want direct from seadoo our site sponsors are Seadoo Warehouse.

 

[arsenic]

Thank you mikidymac

I don't have find this part on the two website but I have find on French website 85€ (92,30$) I will order one next month