Inspection and Verification

Climate Control System

Inspection and Verification

1. Verify the customer concern by operating the climate control system to duplicate the condition.

2. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart






3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

4. 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).


5. NOTE: The Vehicle Communication Module (VCM) LED prove-out confirms voltage and ground from the DLC (Data Link Connector) are provided to the VCM (Vehicle Communication Module).
If the scan tool does not communicate with the VCM (Vehicle Communication Module) :

- check the VCM (Vehicle Communication Module) connection to the vehicle.

- check the scan tool connection to the VCM (Vehicle Communication Module).

- refer to No Power To The Scan Tool, to diagnose no voltage to the scan tool Pinpoint Test R: No Power To The Scan Tool.


6. 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 Information Bus to diagnose no response from the PCM.


7. Carry out the network test.
- If the scan tool responds with no communication from one or more modules, refer to Information Bus.

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


8. Clear the CMDTCs (Continuous Memory Diagnostic Trouble Codes) and carry out the self-test diagnostics from the Instrument Panel Cluster (IPC) and PCM.

9. NOTE: Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to the PCM DTC Chart PCM DTC Chart.

If the PCM DTCs retrieved are related to the concern, go to the PCM DTC Chart PCM DTC Chart. If the IPC (Instrument Panel Cluster) DTCs retrieved are related to the concern, go to the Instrument Panel Cluster (IPC) DTC Chart Instrument Panel Cluster (IPC) DTC Chart. For all other DTCs, refer to Body Control Systems.

10. If no DTCs related to the concern are retrieved, GO to Symptom Chart- Climate Control Systems Symptom Chart - Climate Control System or GO to Symptom Chart- NVH Symptom Chart - NVH.