Coolant Temperature Sensor (Cts)
The coolant temperature sensor is located in thermostat housing. It is a variable resistor (thermistor) type sensor, and transmits an electrical signal to the ECM proportionate to engine temperature. A low coolant temperature produces a high resistance while a high coolant temperature produces a low resistance.
Coolant temperature is used for fuel management, idle air control, spark timing, EGR operation, canister purge operation and other engine operating functions.