DTC P0125: ECT Sensor 1 Malfunction/Slow Response Honda Crosstour I

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION (+).

1. Start the engine, and let it idle for 5 minutes or more.
2. Check ECT SENSOR 1 in the DATA LIST with the HAS. Is about 0°F (-18 °C) or less indicated? YES -Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM. If they are OK, replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(ref-360080-S08997137262010042600000) (+) then go to step 7 . NO -Go to next step.
3. Turn the ignition switch to LOCK (0).
4. Allow the engine to cool to 104 °F (40 °C) or less.
5. 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 next step. 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 PCM.
6. Check the thermostat (see «FAN MOTOR TEST»(ref-360063-S29251781852010042600000) (+). Is the thermostat OK? YES -Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM. If they are OK, replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(ref-360080-S08997137262010042600000) (+) then go to next step. NO -Replace the thermostat (see «THERMOSTAT REPLACEMENT»(ref-360063-S06371123982010042600000) (+) then go to next step.
7. Turn the ignition switch to ON (II).
8. Reset the PCM with the HAS.
9. Turn the ignition switch to LOCK (0).
10. Allow the engine to cool to 104 °F (40 °C) or less.
11. 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.