Troubleshooting

CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temp. sensor changes the resistance value according to the coolant temperature.
The structure of the sensor and connection to the ECM is the same as in the intake air temp. circuit malfunction.
If the ECM records the DTC Poll 5, it operates the fail safe function, in which the engine coolant temp. is assumed to be 80 °C (176 °F).





DETECTING CONDITION

HINT: After confirming DTC P0115 use OBD II scan tool or LEXUS hand-held tester to confirm engine coolant temperature from CURRENT DATA.









WIRING DIAGRAM

INSPECTION PROCEDURE

HINT: If DTCs P0110 (Intake Air Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction), P0120 (Throttle/Pedal Position Sensor/Switch "A" Circuit Malfunction) are output simultaneously, E2 (Sensor ground) may be open.