Circuit Description
WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.
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 those of the intake air temperature sensor.
HINT: If the ECM detects the DTC P0115, P0117 or P0118, it operates the fail-safe mode in which the engine coolant temperature is assumed to be 80°C (176°F).
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 in the DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL.