2005 6.6 duramax check engine

[ceaser_22000]

I have a 2005 GMC Duramax 6.6 while recently coming home through Virginia and West Virginia on North 77 my check engine light came on after about 3 or 4 good mountain passes. Stop for the evening the next morning the engine light came off pulling through the Flatlands no check engine light I don't have a obd reader any ideas I was pulling a 40 foot fifth wheel approximately 13000 pounds.

[LIKE2BUILD]

The 2005 Duramax had some issues with overheating due to air restrictions in the intake design. It's possible that under your towing load that air restriction came into play and the engine was running too hot.

[Tachdriver]

Some auto parts stores like AutoZone can can those codes for you.