I have a check engine light come on but the truck runs fine. I can't pull a code with my scanner and tried with local mechanic's scanner too.
I can erase it and it goes away, and stays away until I restart the truck and drive for 5 minutes, then it reappears.
This happened to me in the fall but eventually went away but now is back. Any insight would be greatly appreciated.

 

You can't do anything until you get the code. There are hundreds if not thousands of parameters monitored by modern cars. You're wasting your time until you have the DTC.

IMO the "Check Engine" light should go away on all vehicles and be replaced with the actual DTCs. CELs were good back when instrument clusters were made up of some needles and lights to illuminate a word or icon. With today's full color LCD IPs, we don't need a CEL, we need the info behind the light.

 

Is your code reader CAN compatible?


There should be no condition that lights the Check Engine light and does not store an ODB/CAN message.

 

I'm not sure if its CAN compatible.

 

If it is not CAN compatible, you will not see any codes.

 

N_Jay it is CAN/OBDII compliant. It's an autel MaxiScan MS300 model.

I also brought it to a mechanic who checked with a more sophisticated scanner and wasn't able to get a code.

 

I would not expect that. Weird!

I can understand error codes readable with only MB tools that don't set a CEL, but the CEL means the emission system need to be checked, and those codes should always be readable with a standard reader.


It would be interesting to find out exactly what the error is and why it is lighting the CEL and not ODB/CAN readable.