Temperature Sensor (Gauge): Description and Operation

The temperature indicating system is a magnetic-type indicating system, consisting of:
- The engine coolant temperature (ECT) sensor located in the engine block or cylinder head.
- An engine coolant temperature gauge in the instrument cluster.

The ECT sensor changes resistance according to engine coolant temperature, which varies the current flow through the engine coolant temperature gauge. The pointer position varies proportionally to the current flow. The engine coolant temperature gauge resistance is high when the engine coolant temperature is low, and low when the engine coolant temperature is high.

The gauge pointer may indicate at the top of the normal band, with the engine coolant temperature within specification. This can occur under certain driving conditions such as heavy traffic or stop and go driving in hot weather.