2000 GT temp guage

2000 GT/121K

On the way into work this morning I noticed my temp guage was sitting all the way down at the bottom 160 mark. I'm in MN so I had the heat on and was getting the normal amount of heat. How can I tell if it's just a dead guage and how do I try to fix it? Thanks.

The sensor that provides the electrical signal to the temp gauge via the PCM module is the ECT - Engine Coolant Temperature sensor. So you would have to check the output of the ECT or you can do a resistance calibration check with a multimeter. Normally if the ECT is bad you would have other issues like a diagnostic trouble code set causing the SES/CEL light or the cooling fans would run continually in fail safe mode. Next step would be to check the signal from the PCM module to the temp gauge to determine of the gauge is bad. That would require removing the IP Cluster and checking the signal at the electrical connectors.

Another way to test the ECT and output of the PCM module before the gauge is with a full function odb-ii scanner that has temperature readout capability.

I had a similar problem on 2000 GTP @ 140k....however I had an equivalent SES code to go along with the bottomed-out needle on the IP. I also had heat.

I elected to change the thermostat and the ECT sensor at the same time, and also put in new radiator hoses as a planned maintenance item.