2005 3D RFI 1 cylinder not firing, Testing with Candoo Pro. Faulty ECM???

[Karlosthejackal]

trying to track down a fault on my 3D RFI. only runs on 1 cylinder constantly. Connected candoo pro and when individually activating coils with plugs removed and earthed can only get 1 to spark. Tested resistance in wiring between coil and ECM and both test perfect (0 ohms), but only 1 will fire a spark. The 12 volt feed to the coils is common so my theory is a faulty ECM?
Any advice or other theories would be gladly appreciated as the ECM is not cheap!!!!!

 

[Karlosthejackal]

Forgot to mention that I have also tried another coil but get the same result.

 

[Waterluvr]

Need to see what you have for stored codes and what it's currently showing as active, disregard the stored crank codes as that automatically stores in history when you're hooked up and not running the ECU can't see it.

The '05 is a very different ECU than the previous years used but it still drops one cylinder at idle rpm's for emissions (it will alternate cylinders)

~If you haven't already done so, reference back to the initial email they sent you when you purchased your Candoo unit it will contain your serial number and that allows you to register for direct access to the private tech forum at candoopro.com (it's included in your license), Dennis has a couple threads on the 05 RFI that should be a big help before getting any further into it.

 

[Karlosthejackal]

It has no active fault codes relevant to this issue. Has one code for an open circuit for the temp lamp ( it does not have one) and the stored crank codes. When testing at the coil plug the 12v feed is good (the middle pin) but one of the switching negatives to fire the coil stays grounded while the engine is not running but the lanyard is on. Am I correct in assuming I should be able to activate either coil while the engine is not running using the Candoo pro software?

 

[Waterluvr]

Morning Karlos, welcome to the forum btw. ~So, does it show any active codes at all aside from the temp lamp? That ECU is really unforgiving on voltage parameters, have you checked the system voltage on the ski while it's sitting static on the trailer and then again while running?

The regulator has been problematic on those causing *limp mode* symptoms, also if you're in need of it the shop manual for your ski is available for download directly from the Sea Doo RFI section on the Candoopro forum it's included in your license fee's.

 

[Karlosthejackal]

Thanks Waterluvr for the reply.
There are no other active codes. The voltage at not running when i am trying to manually activate the coils using the Candoo is 12.74 (12.69 when the bilge pump cycles)Volts and when running it sits around 13.9 to 14 volts, so i am not thinking along the lines of the regulator as i cant fire one coil even when the ski is not running.
The way that one of the signal wires is continuously earthed while the engine is not running is what makes me think the ECU is bad.
From what i can gather this ECU is only used in the 2005 3D RFI....... is that correct???

 

[Waterluvr]

In 2005 they used ECM pn#420665225 and the following model year changed to ECM pn#278002090, if it came down to having to buy one the '05 is significantly less money but I'd bet you don't need one. Let's get Dennis over at CDP involved, he'll likely have an '05 module on his test bench to reference the code triggers he wrote into the software, he's hands down the best resource for troubleshooting help with the system.

I looked back at a few work orders on your model ski and have had some in with heat damage to the exhaust resonators, they were pretty much melt downs and caused the same issue you're having definately have a close look for anything that's causing a restriction.

The temp lamp code is your clue as to why the ECU is isolating a cylinder not allowing you to manually fire the coil, Dennis at CDP can shed a lot more light on it from there for you.

 

[Waterluvr]

Looked into the service history notes a little further this afternoon on the 05's that have come in, on every 3D they all threw the same code you're seeing (P1647) for the temp lamp but they showed it as an active code.

Turns out that ECU was repurposed from a Siemen's module they were using at the time for the snow mobile's that have the temp lamp indicator, so your ecu should be throwing that as an active fault.

 

[Karlosthejackal]

Just had the ski running on the hose pipe (on one cylinder @ all rpm's of course) and refreshed the fault codes which I did not do before . Now im getting a P0351 (coil #1 shorted or open to ground or 12v)
need to do the diagnostic procedure for this code.
Any chance you have that Waterluvr??

 

[Waterluvr]

You made some progress getting that coil to code active. All the BRP service bulletins, manuals etc. you need are free of charge to you on the CDP forum for download that's included at no additional charge to you as part of the fee's you paid for your user license.

Before you get much further into it, if you have a garage/shed/shop where you can pull the ski into a dark unlit area warm it back up on the hose, refresh fault codes lose the water line, shut it down and quick pull it inside where it's dark as possible. Start it right back up and look for fireworks around the coil and it's mount plate, you'll know what to do from there after you read the bulletins on '05 coil bodies.