Coolant Temperature Sensor (CTS)

CTS is mounted in the engine coolant stream on left front corner of intake manifold. This sensor is a thermistor which changes value based on temperature.

Sensor provides coolant temperature information to ECM for fuel enrichment, ignition timing, EGR operation, canister purge control, air management, EFE operation, idle speed control, and closed loop fuel control.

The voltage will be high when engine is cold (sensor high resistance), and low when engine is hot (sensor low resistance).