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-   -   Help needed to resolve insane starting symptom (https://www.ducati.org/forums/999-749/105034-help-needed-resolve-insane-starting-symptom.html)

Johnny999S December 24th, 2017 03:23 AM

Help needed to resolve insane starting symptom
Hi all and Merry Christmas:):)

Bike - 2005 999S
Standard - Stock, Unmodified, Serviced by the book with 35K on the clock (I have had the bike for the past 7 years).

Symptom - Bike would start as per book with all combinations (stand down in neutral or in gear with stand up and clutch in). In the past 2 weeks, the bike now will only start with the stand up and clutch in (either in neutral or in gear)?

I have confirmed the switch gear, clutch switch, stand switch and neutral switch are all working (both by voltmeter and by JPdiag).

The real killer is that the bike will start perfect (first thumb, first turn) with the stand up and then keep running if I put the stand down (in neutral) which further confirms the switch is fine but WTF ??

I cannot believe it's the ECU purely on the level of FUBAR that would be that it allows the bike to start for some of the required combinations but not all?

Any help is appreciated!

Keep safe and enjoy the holiday period!!!

Shazaam! December 24th, 2017 03:30 PM

1 Attachment(s)
If the bike won't start in NEUTRAL with the sidestand UP and the clutch RELEASED, the neutral switch (or circuit) is indicating that the bike is IN GEAR.

Johnny999S December 25th, 2017 04:20 PM

Thanks Shazaam,

When I got the shop manual out and looked at this page, I thought it was one of the switches (clutch, stand or neutral) so checked all of them with voltmeter and JPdiag.

The insane part is through both, all switches test good and the ECU recognizes them as on or off as it should (love JPdiag). This is were I think it could be the ECU but then my rational brain says "hang on, how can the ECU simply stop recognizing some combinations but continue to accept others???". The other point telling me its NOT the ECU is that it runs fine always, no error codes and absolutely no other "gremlins".

Having gone through each combination, it is definitely the injection that is being stopped as the starter operates when it should and doesn't when it shouldn't.

It's the injection which operates when stand up and clutch in but doesn't when either is out/down. BUT ALL SWITCHES TEST GOOD (throwing shit across the shed at this point and wife suggesting I take it to the shop - adding insult to injury!!).

I thought I might be missing something so called out. Thanks again for your input!

Cheers :)

Monster4Lee December 25th, 2017 05:42 PM


Originally Posted by Johnny999S (Post 1154161)
(throwing shit across the shed at this point and wife suggesting I take it to the shop - adding insult to injury!!).
Cheers :)

I hate when my wife tries to be "helpful" when I am PO'd. Just stay out the garage! :wtf:

Shrek December 25th, 2017 08:04 PM

Should be some rectangular relays under the tank near the battery.. about 30mm x 20 mm

Swap them out or over.. side stand relay is often get intermittent no start.

Ashdowns or your favourite repco should be open tomorrow.. take them down should be about 15 bucks each.

Common as poo.. maybe not repco but ashdowns..

Shazaam! December 25th, 2017 08:13 PM

1 Attachment(s)
No error codes from the ECU inputs doesn't mean that the ECU is OK.

I can't fault the logic you're using to solve this problem. A real puzzler. Please post the solution when you find it. Good luck.

Johnny999S December 25th, 2017 09:53 PM

Thanks for the input to date people:) No luck as yet but I am methodically going through each connection, disconnecting, cleaning and re connecting. This is more out of hope as like I stated, Jpdiag recognizes all the switches and their positions.

If it is the ECU, I can live with it so long as it does not continue to lose functionality. Like I said, the bike starts perfect with stand up and clutch in and runs fine (always has). If this is the extent of what-ever has changed/broken then I'll be fine. It's just getting over the fact I may never know!

Should it change again or I do find a reason I will most certainly post it.

Cheers all, I had better get back in the shed and pick up my tools, lucky I have the TV & stereo up high or I would really be pissed now :kaioken:

After packing up, I'll chuck the kids in the pool and forget about it for a few days, way too hot for being annoyed over something that doesn't have any real impact.

Johnny999S December 26th, 2017 10:08 PM


Hi all,

Yes, it got the better of me and I could not leave it for a couple of days (not like you haven't been there:):))

Only thing I did today was actually disconnect the ECU, take it out and visually inspect. All looks good, no grit or grime and all shiny and straight. From a distance, I gently used compressed air to blow out the connectors and put it all back together.

Bike starts as should with stand down, in neutral and clutch out now (and yes, still with stand up, clutch in and in gear:)).

For a technical "solution", I just cannot explain this other than after 12 years, something internally needed a reset (I know, sounds thin but got nothing else!).

Thanks for your help and sorry the answer could explain the meaning of Ducati starting issues but this may just do the trick for someone else who has reached rock bottom?

Cheers and have a great New Year:)

Johnny999S May 10th, 2018 02:08 AM

Hi guy's,

This issue has raised itself again! I have both the battery and ECU out of the bike and came across this reading while testing the wiring harness which I don't understand!

Tested ECU ground cable for continuity to the battery negative connector (red multi meter cable to ECU ground and black cable to the connector) and it has continuity - tick!

I then tested continuity of the ECU ground to the battery positive connector to ensure no short (as my understanding is there should be zero continuity (the ground should not have interference from power).

I don't understand the result as it came back as 596 (not 1 and not 000).

Can someone explain what I am seeing as I am understanding this tells me I have a power line somewhere interfering with my grounding line.

I traced the source to the dash side of the main connector as when I disconnect the connector, I get the result I initially expected (1 - infinite resistance).

Sorry for the cryptic explanation but any help is greatly appreciated.

Cheers :)

Johnny999S May 10th, 2018 06:54 PM

Hi all,

Had another chance to do some diagnosis work and traced the "issue" to the dash itself. If I unplug the dash, the result is as I expected (open circuit with multi meter reading 1).

I checked the power in pins (26 & 23) on the dash and they have continuity between each other as they should (on the wiring diagram there are 2 wires stemming from the one out of the fuse socket).

This confirms to me that the splice/join in the wiring is not the issue and that the dash side pins for power are also soundly connected within the body of the dash itself!

So now, I am past my limit of understanding and am left thinking there is an issue with the dash itself? The only clue here is that sometimes (not all) when the bike doesn't start, the dash flashes "Lo Batt" which according to the manual, will happen if a voltage less than 8.5 is detected while attempting to start.

Totally stumped at this point so any help will be greatly appreciated.

Cheers :)

Monster4Lee May 10th, 2018 07:23 PM


The only clue here is that sometimes (not all) when the bike doesn't start, the dash flashes "Lo Batt" which according to the manual, will happen if a voltage less than 8.5 is detected while attempting to start.
Could it be the infamous weak battery? They cause all sorts of good times. :o

Johnny999S May 10th, 2018 11:56 PM

Thanks Monster but the battery is good (tested).

After my lats post, I realized I had not tested the dash ground pin for continuity to the loom. Tested it and it does so the dash is getting power and the dash is grounded but here is the problem, when I connect the the power pin and the ground pin with the multi meter, I get the 580 reading (not closed or open but crappy). I definitely have an issue with the dash (my understanding anyway)!

Wondering if it's the connector or the circuit board? I see you can buy the dash connector, off ebay for example, but other sites also. Can the existing connector be removed from the dash without breaking it, is it a plug-n-play type connection or is there soldering and board circuitry involved? If i an test the connector separate from the board, I can confirm once and for all if I just have to live with it (not going through the whole dash replacement $$$ to correct an issue that doesn't actually stop me from riding my bike) or if I can fix it with a $80 replacement connector.

Cheers :)

Johnny999S August 21st, 2018 04:52 AM

Finally solved this! Turned out to be two separate issues.

1 - In the main harness connector, the 2 power supply pins to the dash were loose. All the wiring was good so when testing continuity it was all good but under load when starting, not good enough! Lifted the inner tabs for a tight fit and all good!

This was causing the "Lo Batt" warning and triggering the starter being cut to protect it. I can only think that with the stand up and the circuit closed, the flow of power through the system was enough to jump the less than solid connection.

2 - The H2o sensor wiring visibly looked fine and supplied 4.6 volts with the key on. Sensors usually get 5-6 volts but I just put it down to my cheap multi-meter.

After I fixed the loose pins though, I started getting the check engine light and error 3.1 (water temp sensor). So I unwrapped the wiring and much to my surprise, there was a solder connection covered with heat shrink.

After exposing it i gently tugged each side of the solder, it came apart in my hand. Cleaned it all up, crimped on a bullet connector and all good to go.

Bike now starts first thumb with 2-4 cranks each and every time, stand down from cold even when left for a week!

My theory is that the loose pins caused the no starts where the "Lo Batt" was displayed via the ECU logic cutting the starter. The other no-starts were caused by the H2o reading being out due to the low supply so the start-up mixture was wrong and the bike stalls.

Both were overcome by raising the stand which allowed a better power flow through the system!

What an absolute journey, but, I have the bike sorted now and have become very "capable" at taking that battery box out! I can have the ECU, solenoid, injector relay and box all on my bench within 20 odd minutes and then back together in just a little longer (nothing ever goes back together as quick as you can take it apart??).

Cheers :)

jet057 February 6th, 2019 08:39 PM


Originally Posted by Shazaam! (Post 1154209)
No error codes from the ECU inputs doesn't mean that the ECU is OK.

I can't fault the logic you're using to solve this problem. A real puzzler. Please post the solution when you find it. Good luck.

,,,What Buttons ?

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