P0217

P0217-COOLANT TEMPERATURE TOO HIGH

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Coolant Temperature Sensor is a variable resistor sensor and is used to measure the temperature of the coolant of the engine. The PCM supplies 5-Volts to the Engine Coolant Temperature Sensor (ECT) Signal circuit. The PCM monitors the change in voltage caused by changes in the resistance of the sensor to determine the coolant temperature. The engine coolant temperature value is used by the PCM for the engine protection system and engine emissions control. The Engine Coolant Temperature Sensor is located near the thermostat housing. This fault becomes active when the PCM detects a coolant temperature higher than a calibrated limit for a calibrated amount of time. The PCM illuminates the MIL lamp after the diagnostic runs and fails once. During this time the customer may experience an engine power derate, and regeneration mode will be disabled. The PCM will turn off the MIL lamp after the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
While the engine is running.

- Set Condition:
The engine coolant temperature is above a calibrated value for a calibrated amount of time.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. COOLING SYSTEM FAILURE

NOTE: If other cooling system DTCs are present, repair those DTCs before proceeding.

1. Check the engine cooling system operation. Refer to cooling, Diagnosis and Testing, Preliminary check. Component Tests and General Diagnostics.

Is the Cooling system operating normally?

Yes

- Go To 2

No

- Repair the cooling system failure.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

2. CHECK THE ECT SENSOR
1. Allow the engine to reach normal operating temperature.
2. Use a temperature probe and measure the engine temperature near the ECT Sensor.
3. With the scan tool, read the Engine Coolant Temperature.
4. Compare the temperature probe reading with the scan tool reading.

Are the readings within 10°F of each other?

Yes

- Repair the cause of mechanical failure.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the Engine Coolant Temperature Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.