So I recently purchased a 2002 f150 with the FX4 package and 5 speed manual. I had it hooked up to a scan tool to check for codes. One of the codes that came up was something to the effect of "failed to complete OBD drive cycle". That wasn't the oddest part. While viewing live data, the engine coolant temperature sensor it read about 118 degrees. (the truck had only been idling for a less than 5 minutes) However, the cylinder head temp read 392 degrees. The truck ran fine and didn't act like it was overheating. From my understanding, the cylinder head temp sensor is what determines head temp AND coolant temp info. Could someone help shed some light on this confusing truck. Thanks for reading.

 

Was the code P1000? That means that the battery was recently disconnected or the PCM fuse was recently pulled and it takes time to get all the sensors in a ready status. If you don't have a CEL on, you don't have a problem if that's the only code.