Circuit Description

A thermistor is built in the Engine Coolant Temperature (ECT) sensor and changes the resistance value according to the engine coolant temperature.

The structure of the sensor and connection to the ECM is the same the Intake Air Temperature (IAT) sensor.

HINT:

If the ECM detects the DTC "P0115, P0117 or P0118", it operates the fail-safe function in which the ECT is assumed to be 80°C (176°F).

Fig 1: DTC Detecting Condition Chart

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HINT:

After confirming DTC "P0115, P0117 or P0118," use the OBD II scan tool or the hand-held tester to confirm the engine coolant temperature from the DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL.