My problems started with a "Check Coolant Level" message that appeared on my DIC when I knew the coolant tank was full. Later the gas gauge started moving up and down without correlation to the amount of fuel in the tank (it went from half full to full within five minutes when I knew the tank was nearly empty - I first thought I had invented a gasoline refining car, but that seemed a bit unlikely). The next issue was the instantaneous and average mileage indicator, which was anomalously high. I am guessing some computer module has gone bad. Is there a module that controls the gas gauge, the coolant indicator, and the instantaneous mileage? Do I just have two sensors that went bad at the same time? I would appreciate any advice.

 

Unplug the coolant level sensor. Its under the resevior.
If the light goes out and the tank is full, you have a bad sensor.

The fuel guage issuse has been seen from time to time.
It's almost always due to some sort of build up on the sender(in the tank).

The high mpg is related to the inaccurate fuel level signal.

It could be a bad computer, but that would be the less likely.

 

Thanks a million, FLCaddytech. Well, at least thanks $92 an hour, which is what the local dealership charges for diagnostics. I read somewhere else that an eraser can be used to clean the fuel sender(might have been more of your wisdom). I will give that a try before I throw money at the problem.