DTC P0125

DTC P0125  : ECT Sensor 1 Malfunction/Slow Response

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems,  or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016),  or How to Troubleshoot the A/T System (2014 2015) .

DTC (PGM-FI)

1. ECT sensor 1 check

   -1. Start the engine, and let it idle for 5 minutes or more.

   - 2. Check the parameter(s) below with the HDS.

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   ECT SENSOR 1	Less than 10	°F

   Do the current condition(s) match the threshold?

   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 - Refer to: ECT Sensor 1 Removal and Installation, or ECT Sensor 2 Removal and Installation .

   NO 

   Go to step 2.

2. Problem verification

   -1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Allow the engine to cool to 104 °F (40 °C) or less.

   - 3. Start the engine, and let it idle until ECT SENSOR 1 goes up to about 158 °F (70 °C).

   Signal	Current conditions
   	Values	Unit
   ECT SENSOR 1

   - 4. Check the parameter(s) below with the HDS.

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   ECT SENSOR 2	About 158	°F

   Do the current condition(s) match the threshold?

   YES 

   The failure is duplicated. Go to step 3.

   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. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

3. Thermostat check

   -1. Check the thermostat.

   Is the thermostat OK?

   YES 

   Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM. If the connections and terminals are OK, replace ECT sensor 1 - Refer to: ECT Sensor 1 Removal and Installation, or ECT Sensor 2 Removal and Installation .

   NO 

   Replace the thermostat - Refer to: Thermostat Removal, Installation, and Test (2016), or Thermostat Removal, Installation, and Test (2014 2015) .