My check engine light came on yesterday after driving 5 or 6 miles going 40 mph and hasn't gone out after 150 more miles. I tried the on/off key thing to see codes but no codes show. Truck runs great , what could be wrong? Can I clear the problem or does it have to go to Dealer?

 

i had the same thing happen to my truck when it was relatively new. the engine light came on and there was no "code" present, not with the 3 key cycle or on my code reader. It went away a few hours and a few starts later. I chalked it up to a cold start as I don't think I let the grid heater fully warm. Hope that helps.

 

Thanks red . Was checking the oil level this AM and wiggled on a few of the cable connections under the hood and check engine light was gone on next startup. Go figure.