Circuit Description

ECT sensor is a thermistor that monitors coolant temperature. If DTC P0115 is set, ECM will operate in fail-safe mode. During fail-safe mode, engine coolant temperature is fixed at 176°F (80°C). DTC is set when ECM detects a open or short in the ECT circuit. Possible causes are:

Open or short in ECT sensor circuit.
Faulty ECT sensor.
Faulty ECM.

NOTE: If DTCs P0110, P0115, P0120, P0450 and P1120 are output together, inspect ECM terminal ground circuit(s) for an open. Repair as necessary. See appropriate wiring diagram in WIRING DIAGRAMS article.