Possible Causes
WARNING: This page is about a different car, the 2003 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when ECM detects an open or short in ECT sensor circuit. If DTC P0115 exists, ECM will operate in fail-safe mode in which engine coolant temperature is assumed to be 176°F (80°C). Possible causes are:
- ECT sensor circuit is open or shorted.
- Defective ECT sensor.
- Defective ECM.