Home/Lexus/LS/Lexus LS II (1994-2000)/Repair manual/Testing & Diagnostics/DTC P0115: ENGINE COOLANT TEMPERATURE (ECT) SENSOR CIRCUIT

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DTC P0115: ENGINE COOLANT TEMPERATURE (ECT) SENSOR CIRCUIT Lexus LS II

Testing & Diagnostics

CAUTION

If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction.

Circuit Description

The ECT sensor is a thermistor that monitors coolant temperature. DTC is set when ECM detects a open or short circuit. Possible causes are

ECT sensor open or short circuit.
ECT sensor.
ECM.

Note. If DTCs P0110, P0115 and P0120 are output together, inspect ECM terminal E2 (ground) circuit. Repair as needed. See appropriate wiring diagram in WIRING DIAGRAMS article.