Chrysler Repair: Chrysler - coolant temperature sensor (too low), chrysler concorde lxi, coolant temperature sensor

Question
I have a 2002 Chrysler Concorde LXI 3.5 V6. My check engine light is on and my fault code shows that the coolant temperature is too low.  Can the coolant temperature sensor be faulty and can it be changed easily?  Where is it located?  How can I test it to see if it is a faulty sensor?  If not faulty why would it show 'too low'.  My dash coolant guage shows that the coolant is correctly up to temperature.

Answer
Hi Alan,
Yes, the coolant temp sensor can be faulty and can be changed easily. It is located adjacent to the thermostat housing which is at the engine-end of the large coolant hose that runs to the top of the radiator from the top of the cylinder head. It screws into the head, and it has an electrical connector with tan/black and black/light blue wires. To test it, you unplug the connector and measure the resistance across its teminals with an ohmmeter. When the coolant is cold it should read 7,000 to 14,000 ohms while when at operating temp it should read 700-1,000 ohm. If it doesn't change in that approximate way, then change it. You might want to use a little anti-seize compound on the threads; torque to 20 ft-lbs (about the same as a spark plug).
If it does respond to temp change correctly,  then verify that the temp gauge is about right by measuring the temp of the coolant before the system pressurizes with a thermometer. Another test of the wiring is to have the engine warmed up and running and then remove the sensor's plug which if the wiring is o.k. will cause the cooling fan to start up.
Let me know if this approach doesn't work to resolve the issue for you.
Roland