2008 Seadoo Challenger 230 says p1656 but 1 engine starts fine

[bonelaw]

As description says, I have the check engine code: p1656 dess post line shorted to ground. When I put the key on it beeps bad for one, then normal for second engine.

Starboard engine starts no problem. Port engine will not even turn over. Starter engages strong when jumping the solenoid. When I swapped the solenoid with the other engine the other engine still started fine. Same situation on starboard engine. I swapped the box near the engine with fuses in it and the other engine still worked fine.

Has two batteries on board. Gauge reads 12v. What problem could be isolated to just one engine?

Where should I look next? Grounds on starboard engine? All fuses fine that I could find.

 

[ski-d00]

switch ECUs and see if the problem follows the ECU

 

[bonelaw]

Is that the black box in the engine bay that the service port plugs into? I did switch that and problems still stayed with the port engine. I'm thinking a ground to that side is having an issue. Where can I find the ground points?

 

[ski-d00]

No, the ECU is sitting on top of the intake manifold

 

[bonelaw]

Oh interesting. Thank you. I'll try it.

 

[bonelaw]

HALLELUJAH!! I swapped the ecus and the engine that hasn't started in forever fired up. The engine that has been working fine wouldn't start with the swapped ECU. Thank you. Thank you. Do I just buy one off of eBay? Do they have to be particular to the boat?

 

[ski-d00]

Are you sure that your boat is a 2008? That ECU is specific to a 2007 155 boat or a 2006 155 ski. You have to buy the exact ECU for your boat and yours is a little bit of an oddball ECU only made 1 year since it was a transition year between different electronic systems. The part number you need is 420664136 and is going to be expensive.

 

[bonelaw]

Hull is CEC245061708. It is a 310 though.

I just ordered a used but working one off of eBay using the part number. $200

Thanks again for the help. I'll report the outcome.

 

[ski-d00]

Okay, so it is a 2008 but they used a 2006 system which boats typically used 1 year old systems but must have been trying to finish up old systems on your early 2008 model.

I would be really surprised if you got a working ECU on ebay for $200. Did it say "CORE NO SPARK" in the title or description which means it doesn't work? They usually cost at least $800 for working ones of that model.

 

[bonelaw]

It said good used condition and the numbers all matched so I went for it.

 

[ski-d00]

But did it say core, or no spark? A lot of sellers say good used condition but to them it doesn't mean that it works. Do they accept returns?

 

[bonelaw]

 

[ski-d00]

Nice find. If I saw it, I would have bought it. You won't be able to check the hours on it, need software to check or dealer, but it doesn't really matter.

 

[bonelaw]

I have candoo. I was able to install the used CPU. It had 68 hours on it. After I installed it and set the engine number and model number and programmed a key to it the engine actually turned over but wouldn't start. It threw a P0339 code. When I swapped the CPU to the other engine it threw the same code. Any idea why it would be doing that?

 

[ski-d00]

That is a timing issue between the CPS and caps sensors. Do your magneto 3 yellow wires come out of the PTO house at the back center or do you have the CPS at the 7 o'clock position? I suspect that ECU is for the different system even though your part numbers match.