Circuit Description

A thermistor is built in the engine coolant temperature sensor changes the resistance value according to the engine coolant temperature.

The structure of the sensor and connection to the ECM is the same as those of the intake air temperature sensor.

HINT:

If the ECM detects the DTC P0115, P0117 or P0118, the ECM enter fail-safe function in which the engine coolant temperature is assumed to be 80 °C (176 °F).

Fig 1: Identifying Engine Coolant Temperature Circuit High Input

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HINT:

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

Fig 2: DTC Problem Symptom Chart