DTC P0125: ECT Sensor 1 Malfunction/Slow Response
- Start the engine, and let it idle for 5 minutes or more.
- Check ECT SENSOR 1 in the DATA LIST with the HDS.
Is about 10°F (-12°C) or less indicated?
YES - Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the ECM/PCM. If the connections and the terminals are OK, replace ECT sensor 1 (see ECT Sensor 1 Replacement ), then go to step 7.
NO - Go to step 3.
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Allow the engine to cool to 104°F (40°C) or less.
- Start the engine, and let it idle until ECT SENSOR 1 goes up to about 158°F (70°C).
Does ECT SENSOR 2 also read about 158°F (70°C)?
YES - Go to step 6.
NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the ECM/PCM. ■
- Check the thermostat (see
FAN MOTOR TEST
).
Is the thermostat OK?
YES - Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the ECM/PCM. If the connections and the terminals are OK, replace ECT sensor 1 (see ECT Sensor 1 Replacement ), then go to step 7.
NO - Replace the thermostat (see THERMOSTAT REPLACEMENT ), then go to step 7.
- Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
- Reset the ECM/PCM with the HDS.
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Allow the engine to cool to 104°F (40°C) or less.
- Start the engine, and let it idle until ECT SENSOR 1 goes up to about 158°F (70°C).
Does ECT SENSOR 2 also read about 158°F (70°C)?
YES - Go to step 1 and recheck.
NO - Troubleshooting is complete. ■