limp mode mystery

[txjim]

Idled around the lake about an hour, hit the gas to go home, engine stutters, engine light comes on, limp mode activates. Coincidentally turned 50 hours at the same time. Scarab 165 with Rotax 4-tec 150. Now, engine light comes on at start and engine stays in limp mode. Pressing "Set" 5x shows no code, just "check engine" message scrolls once. Any ideas?

Nearest service is 300 miles away and I'm reasonably skilled so I'd like to exhaust possibilities before considering a road trip.

The only visual clue is slight discoloration on the base of the second O2 sensor, like is has been hot. Doesn't necessarily look abnormal. Is there a way to jump the O2 sensors and see if the fault goes away? That would at least confirm/deny an error related to O2.

Any help is extremely appreciated. Thanks!

 

[Luc Lafreniere]

So you don't get the fault co option based on this menu?

I doubt it's an O2 sensor.. that does not cause limp mode to my knowledge.

If it's an active problem, the fault code should be available.

Otherwise I'd start with standard stuff like plugs. Make sure your battery is in good shape. Make sure your coolant levels are good. Check your oil level.

 

[txjim]

Thanks Luc! We have the same boat and year model but I have dumber dash so my modes are only "display" and "settings". But, I did get a clue out of this: when the display scrolls "check engine", in half a blink of an eye there is a message that precedes "check engine". It's nearly off the screen when it starts but ends in "pressure". Assuming that must be an oil warning, I found the cap off the fill tube and oil level at minimum.

If the error is indeed oil level, adding oil should satisfy the sensor but will the fault clear on its own and get me out of limp mode? Or, will clearing the fault require a Candoo?

 

[Luc Lafreniere]

Oh, don't you worry, I have the dumb dash too. lol Those other options is if you paid for the special settings. I'm cheap.

Low oil will definitely cause issues. Glad you found that. Many codes clear after running the engine for a certain amount of time and sessions. I suspect yours will clear very quickly if that was indeed the problem.

 

[Kchonline]

Thanks Luc! We have the same boat and year model but I have dumber dash so my modes are only "display" and "settings". But, I did get a clue out of this: when the display scrolls "check engine", in half a blink of an eye there is a message that precedes "check engine". It's nearly off the screen when it starts but ends in "pressure". Assuming that must be an oil warning, I found the cap off the fill tube and oil level at minimum.

If the error is indeed oil level, adding oil should satisfy the sensor but will the fault clear on its own and get me out of limp mode? Or, will clearing the fault require a Candoo?

Following...I have the same issue. Did your fault clear, limp mode deactivated?