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 as the Intake Air Temperature (IAT) sensor.

HINT:

If the ECM detects the DTC P0115, it operates fail safe function in which the engine coolant temperature is assumed to be 80°C (176°F).

Fig 1: DTC P0115 Troubleshooting Table

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HINT:

After confirming DTC P0115, confirm the engine coolant temperature with the hand-held tester or the OBD II scan tool. Enter the following manus: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL.