Troubleshooting

DTC P0115 Engine Coolant Temp. Circuit Malfunction

CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temp. sensor changes the resistance value according to the engine coolant temp.
The structure of the sensor and connection to the ECM is the same as in the intake air temp. circuit malfunction.
If the ECM detects the DTC P0115, 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 the OBD II scan tool or LEXUS hand-held tester to confirm the engine coolant temp. from CURRENT DATA.





WIRING DIAGRAM

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INSPECTION PROCEDURE

HINT: If DTC P0110 (Intake Air Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction), P0120 (Throttle/Pedal/Position Sensor/Switch "A" Circuit Malfunction) and P1410 (EGR Valve Position Sensor Circuit Malfunction) are output simultaneously, E2 (Sensor Ground) may be open.