DTC P0125

DTC P0125  : ECT Sensor 1 Malfunction/Slow Response

NOTE:  Before you troubleshoot, review the general troubleshooting information .

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	deg. F
   	Less than -12	deg. C

   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 .

   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	deg. F
   	About 70	deg. C

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

   NO 

   Replace the thermostat .