Inspection and Verification

Engine Cooling

Inspection and Verification

WARNING: Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in serious personal injury.

NOTICE: Always fill the cooling system with the manufacturer's specified coolant. If a non-specified coolant has been used the cooling system must be chemically flushed. Refer to Cooling System Flushing. Failure to follow these instructions may damage the engine or cooling system. Cooling System Flushing

1. Verify the customer concern.

2. Visually check the engine coolant level at the degas bottle when the system is cold.

3. Make sure the pressure relief cap is installed correctly.

4. Record any cooling system DTCs retrieved. Refer to the PCM DTC Chart for DTC descriptions. Engine Cooling

5. NOTE: Take note of any coolant odor or steam coming from cooling system components.

If the system coolant is filled correctly and no DTCs associated with fail-safe cooling are retrieved, verify the customer concern by operating the engine to duplicate the condition.

6. NOTE: For the coolant flow diagrams, refer to Engine Cooling Engine Cooling in the Description and Operation information.

Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart





7. If the inspection reveals an obvious concern that can be readily identified, repair it as necessary. Test the system for normal operation.

8. Evaluate the coolant condition. For additional information , refer to Coolant Test Coolant Test.

9. If an obvious cause for an observed or reported concern is found, correct the cause and test the system for normal operation before proceeding to the next step.

10. NOTE: Make sure to use the latest scan tool software release.

If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).

11. NOTE: The Vehicle Communication Module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM.

If the scan tool does not communicate with the VCM:

- check the VCM connection to the vehicle.

- check the scan tool connection to the VCM.

- refer to Module Communications Network Testing and Inspection, No Power To The Scan Tool, to diagnose no power to the scan tool.

12. If the scan tool does not communicate with the vehicle:
- verify the ignition key is in the ON position.

- verify the scan tool operation with a known good vehicle.

- refer to Module Communications Network Testing and Inspection to diagnose no response from the PCM.

13. Carry out the network test.
- If the scan tool responds with no communication for one or more modules, refer to Module Communications Network Testing and Inspection.

- If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).

14. Clear the continuous DTCs and carry out the self-test diagnostics for the PCM.

15. If the DTCs recovered are related to the concern, go to the PCM DTC Chart Engine Cooling. For all other DTCs, refer to Multifunction Electronic Modules Testing and Inspection.

16. If no DTCs related to the concern are retrieved, GO to Symptom Chart. Engine Cooling