So, I noticed Sunday that when I started the car up from a cold start, the coolant sensor said that the car was warm, but nobody had touched it from when I came home from work on Saturday. Started it up again today also from cold, and it said again that the car was warm even though nobody had touched it. The coolant level was fine, and it did not overheat, staying just below the halfway mark, and I also did not get a trouble code for the sensor. So does anyone know if it could be the sensor on the engine or if there is one in the dashboard? Also, what is the resistance spec I should be looking for on the Coolant Sensor?

 

The coolant temperature sending unit for the gauge cluster is on the engine. There is a sending unit and ECT sensor side by side on the head under the distributor/passenger side. The temp sending unit for the gauge cluster is the single wire brass fitting under the distributor. The 2 wire engine coolant temperature sensor next to it is for the ECU.

This thread might help; 90-02 Accord Temp gauge problem

 

first test your gauge by disconnecting the sensor than grounding the wire with a jumper. Turn the car to on and watch the gauge. Do not let it max out, it can ruin it. If it doesn’t work check the wiring. The sensor should have 142 ohms at 133 degrees F.
On a hot engine 32-49 ohms.
if all works it is your gauge