DTC Troubleshooting: P0125 (86)

DTC P0125:  Cooling System Malfunction

1.Turn the ignition switch ON (II).

2.Do the DTC CLEAR in the CLEAR MENU with the HDS.

3.Start the engine. Hold the engine speed at 3,000 rpm (min-1) with no load (in neutral) until the radiator fan comes on, then let it idle.

4.Check the ECT SENSOR in the DATA LIST with the HDS.

Is about 27°C (81°F) or higher, or 2.83 V or less indicated?


YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the ECT sensor and the ECM.n


NO - Go to 5.


5.Turn the ignition switch OFF.

6.Replace the ECT sensor.

7.Turn the ignition switch ON (II).

8.Do the ECM RESET in the CLEAR MENU the HDS.

9.Do the ETCS learn procedure.

10.Start the engine. Hold the engine speed at 3,000 rpm (min-1) with no load (in neutral) until the radiator fan comes on, then let it idle.

11.Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0125 is indicated, check for poor connections or loose terminals at the ECT sensor and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Troubleshooting is complete.n