| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM connectors 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 sensor that monitors engine coolant temperature. DTC is set when ECM detects an open or short circuit. Possible causes are
- Open or short in ECT sensor circuit.
- ECT sensor.
- ECM.
Note. If DTCs P0105, P0110, P0115 and P0120 are output together, inspect ECM terminal E2 (ground) circuit. Repair as necessary. See appropriate wiring diagram in WIRING DIAGRAMS article.