The other day while driving to the shore after going thru a circle the shifter light was flashing. I didnt want to stop because the truck was driving fine. After unloading and sitting for 4 hours the truck is fine, Any ideas on what it could be? No lights were lite when it was happening.

 

The transmission has set a code, you need to have it scanned to find out what code is set then I can help point you in the right direction.