Quote:
Originally Posted by Mkok
What I am curious about is would - COULD a loose gas cap make the traction light come on??? (in combination with the CEL)
|
Are these cars throttle by wire? If so TC could get disabled as a safety feature. In the ODB specifications if certain types of faults are detected the engine program switches to a limp in mode set of static parameters killing automatic controls like TC. Cars that are throttle by wire give TC the ability to close the throttle plate regardless of what the accel pedal is doing. closing the throttle plate to reduce engine power is preferred than to killing an injector or spark because it messes up your emissions.
A loose/missing gas cap usually triggers a EVAP Large leak code. This is considered a severe fault as you have a leak severe enough to possibly allow raw fuel out. Ford years ago added a second EVAP test valve to the gas filler that triggered a gas cap light on the dash.
When I was a mechanic I would get almost 1 case a month for engine code diag due to gas caps being left off or loose. It happens..