Hi, all.
For the past several months, I've been using 100% gasoline; no ethanol. My mileage is better and I have not had any problem with fail codes. But this last fill up, I put in gas with ethanol and almost immediately I had a fuel fail code, but no number, which is odd. So I disconnected the battery, to reset the computer, and all was well until today when the Fuel Fail 17 code came up. What does this code mean? I looked in my Haynes manual, but it just says the throttle potentiometer is not in operating range. The car is running just fine. What am I missing?

 

The car's handbook also says: "throttle pot or associated wiring. Looks for throttle pot resistance out of range." Those TPS's can become very clogged and dirty with gunk over time. But my understanding is that they are sensitive to being moved off of the throttle body requiring fairly precise calibration in re-installation. If it were me, I'd clear the code by removing the negative battery terminal for 30 seconds or more (remembering that you need the radio code to get it working again!) and see if it throws up the code again. If not, or if the car is running well, perhaps it was just a fluke.

Scott

 

Thanks for the feedback, Scott. I'm going to give that a try and see what she does. I have a trip this weekend from Tulsa to Kentucky and I was hoping to take the Jaguar. Maybe it'll work out.

 

Well, the code came back today. It showed up just as I started the engine while parked at a fast food restaurant. And, coincidentally, my cruise control stopped working. Could there be a connection between the fail code and the cruise control failure?

 

The cruise control reset switch under the dash was tripped. No fuel fail code now. Hmmm.