Circuit/System Verification
- Verify the cooling system is filled to the correct coolant level. Refer to Cooling System Leak Testing
, and Cooling System Draining and Filling
.
- If the coolant level is not correct
Repair as necessary
- If the coolant level is correct
- If the coolant level is not correct
- Verify the proper heat range and the operation of the thermostat. Refer to Thermostat Diagnosis
.
- If a condition is found
Replace the Thermostat.
- If a condition is not found
- If a condition is found
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
- Verify the DTC does not set.
- If the DTC sets
Refer to Step 1.
- If the DTC does not set
- If the DTC sets
- All OK.
NOTE:
A critical analysis of the operation of the thermostat is necessary to properly diagnose this DTC.