Cooling fan won't stop running

A thermostat that is stuck open will not cause the engine to overheat! The trouble code you got is for the cylinder head temperature sensor. Sounds like the sensor is bad or the wiring going to the sensor is damaged causing a bad connection. When this happens the PCM is not receiving a signal from the cylinder head temperature sensor so the PCM assumes the engine is overheating. There is also a special refill procedure for this vehicle's cooling system. With the engine cold remove the cap from the plastic coolant recovery tank. Remove the thermostat housing and thermostat. Refill the cooling system by pouring coolant into the thermostat hole. When it's full put the thermostat and thermostat housing back on and start the engine. Fill the plastic coolant recovery tank to the full cold line and keep an eye on the coolant level. As the engine warms up the coolant level may drop down. Keep topping off the coolant recovery tank until the engine is fully warmed up and the coolant level stops dropping down. Be patient, this can take up to 30 minutes or so. Then put the cap on the coolant recovery tank and you should be all set. One other thing, if the fan still remains on, let another mechanic look at it. The one you've been using doesn't know what he's doing!! Hope that helps! Jim

Thank you we did change cylinder head temperature sensor but we are suspecting it's a short in the wires connected to the chts, probably was the problem all along actually I just don't want it to be the PCM. Again thank you for taking time to answer my question.

You're welcome. Glad to help! Jim