I have an 04 Lariat Supercrew 4x4 with the 5.4. I bought it a couple of weeks ago. The check engine light has come on with the following 3 codes. P1299, P0119 and P1290. I think it is an electrical problem, but where do I start? The sending unit? The temp has been running about mid-gauge, then jumps to HOT...engine reduces power and idles rough. If I kill it and start it back up immediately it is fine for a little while. Has anyone else had this problem?

 

Take each code and enter it in the Google box (google.com). You will find plenty of reading material to help you understand what's wrong, and where to start.

 

P0119 is an intermittent coolant sensor,
P1290 Cylinder Head Temperature Sensor Circuit Low Input

P1299 Cylinder Head Overtemperature Protection Active