Circuit Description
WARNING: This page is about a different car, the 2003 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
Engine Coolant Temperature (ECT) sensor is a thermistor that monitors coolant temperature. See Fig 1. If DTC 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 an open or short in ECT sensor circuit. Possible causes are:
- Open or short in ECT sensor circuit.
- Faulty ECT sensor.
- Faulty ECM.