RandomHunter208
New Member
I recently picked up a 2005 Expedition with a 5.4L 3v, and have been working my way through all of the little issues. I think I have it about wrapped up but I cannot seem to figure out what going on with the P1289 code for the Cylinder Head Sensor. I replaced the sensor and inspected the wiring all the way to the PCM and have no reason to think the new sensor is faulty. When I view the live data the scanner shows an engine temp of 55 c (doesnt change), and the gauge on the dash doesn't move. No lights are on the dash to indicate any other problems. When I clear the code and reset the PCM the truck will run great until the thermostat opens, then the code comes back and the engine falls into a rough idle and doesn't want to run. My suspicion is that the PCM is probably bad, unforcedly because of the year I can't seem to easily locate a replacement at the locate yards to check, and outside of a gut feeling I don't have a reason to spend another 200 bucks to throw parts at this thing. Has anyone had similar issues or is more familiar with this vehicle? Everything seems to be tied to the temperature issue.
No vacuum leaks
New TPS sensor (3rd gen)
New CHT sensor
No Misfires
The temp Gauge is not working
No vacuum leaks
New TPS sensor (3rd gen)
New CHT sensor
No Misfires
The temp Gauge is not working