P0217

P0217-COOLANT TEMPERATURE TOO HIGH

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

Theory of Operation

The Engine Coolant Temperature (ECT) Sensor is a variable resistor sensor and is used to measure the temperature of the coolant of the engine. The Powertrain Control Module (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 sets the fault after the diagnostic runs and fails once, but will not turn on the MIL Lamp. During this time the customer may experience an engine power derate, and regeneration mode will be disabled. This fault indicates that an overheat condition has occurred.

- 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.
COOLING SYSTEM FAILURE

NOTE: If other ECT Sensor DTCs are present, repair those DTCs before proceeding.

1. Check the engine cooling system operation. Component Tests and General Diagnostics Perform the Preliminary Check.

Is the Cooling system operating normally?

Yes

- Intermittent condition may have been caused by specific customer driving condition that produced an overheat.

No

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