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. Inspect to determine if one of the following mechanical or electrical concerns apply:

Visual Inspection Chart:

3. As pinpoint tests and measurements are being carried out, be sure to inspect for any disconnected, loose-fitting or incorrectly installed component, module and in-line electrical connectors and pins.

4. If the inspection reveals obvious concerns that can be readily identified, repair as necessary.

5. 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).

6. 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 Information Bus, No Power To The Scan Tool, to diagnose no power to the scan tool.

7. 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, HVAC module - Electronic Automatic Temperature Control (EATC) or HVAC module - Dual Automatic Temperature Control (DATC).

8. 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 continuous memory DTCs.

9. Carry out the self-test diagnostics for the PCM, HVAC module - EATC or HVAC module - DATC.

10. NOTE: Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to the PCM DTC Chart. Diagnostic Trouble Code Tests and Associated Procedures

If any of the HVAC module - EATC or HVAC module - DATC DTCs retrieved are related to the concern, refer to the HVAC Module - Electronic Automatic Temperature Control (EATC) and HVAC Module - Dual Automatic Temperature Control (DATC) DTC Chart. If the PCM DTCs retrieved are related to the concern, refer to the PCM DTC Chart. For all other DTCs, refer to Body Control Systems. Diagnostic Trouble Code Tests and Associated Procedures Diagnostic Trouble Code (DTC) Chart

11. If no DTCs related to the concern are retrieved, GO to Symptom Chart - Climate Control Systems or GO to Symptom Chart - NVH. Symptom Related Diagnostic Procedures