A new limp mode scenario...

[FlossyTheSmart]

So today at the Midwest rally, we drove up a pretty steep hill, and when I started gunning it, I went into limp mode. No check engine light, nothing coming up on the Scangauge. No indications of the issue existing, beyond not being able to go over 3000 RPM, and terrible performance. Interestingly, the same issue had occured when I was driving up the Cherohala Skyway at Outsmarting the Dragon last year.

This is all in my 2006 CDI cabrio.

As I said before, the CEL wasn't lit up, just "unexplained" limp mode. When I got back to the hotel, I plugged in the Star machine, and got the following fault:

P2102 - Reversible fuel safety cutoff: Implausible value in the run-on time

I had 3 out of 5 blobs of fuel in the tank, so it's not like I ran the car dry or anything. As I said, it was going up a steep hill though.

Anyone have any thoughts on this one? It feels like some faulty sensor to me (because of the "implausible value"), but any input would be appreciated.

[MikeT]

What is the reversible fuel safety cutoff?

[Francesco]

I would suspect a short. I've had a few "implausible", "low" or "high" values in a variety of sensors or circuits that I've been able to trace to either chafed or broken wires or wet connectors (after a big puddle or during a downpour).

[FlossyTheSmart]

What is the reversible fuel safety cutoff?

I think this is the first part of the question for sure. I think what it means by "reversible" is that it isn't a permanent one-time cut off. It can be undone (by clearing the code?). The question is though, what sensor is it that is getting an implausible reading, and results in the car deciding it needs to cut off the fuel supply for safety reasons? And how would the angle of the car play into it?

Perhaps the sensor that reads the fuel level, and going up hill, the wire moves in such a way that it shorts/disconnects? Seems unlikely that this would only happen going up a steep hill.

I would suspect a short. I've had a few "implausible", "low" or "high" values in a variety of sensors or circuits that I've been able to trace to either chafed or broken wires or wet connectors (after a big puddle or during a downpour).

Yes, this is a good point. Of course, not knowing what sensor it is that is getting the implausible reading makes it hard to know where to start. WIS and DAS don't seem to mention a fuel cutoff anywhere that I could find.

[jwight]

I've not seen this mentioned for any smarts, but there are cars with sensors that disable the electric fuel pump in the event the car rolls in a crash.

[FlossyTheSmart]

A tilt sensor could make sense. If it was misaligned, a hill could be sensed as a flip...

[Francesco]

Yeah, that's what I was thinking. Maybe this "sensor" is part of the crash module that activates the hazards?

[FlossyTheSmart]

I had lots of time to think about this yesterday, and the more I thought about it, the more certain I am that you guys are right, with it being related to an after-crash scenario. If you rolled over and the car was still driveable, they would want you to take it into a dealer to make sure everything is OK. They don't want you running around at high speed, just enough oomph to get you off the road and to safety. Once you get to the dealer, they'd look everything over and clear the cutoff code, giving you your full oomph back.

I guess it's time to do some digging to see if we have some sort of roll sensor, or what other accident-detecting sensors we've got that could be messed up.