Inspection and Verification
Climate Control System
Inspection and Verification
1. Verify the customer's 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. If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
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 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 VCM.
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 Module Communications Network Testing and Inspection to diagnose no response from the PCM, HVAC module - Electronic Manual Temperature Control (EMTC) or HVAC module - Dual Automatic Temperature Control (DATC).
7. Carry out the network test.
- If the scan tool responds with no communication from one or more modules, refer to Module Communications Network Testing and Inspection.
- If the network test passes, retrieve and record the Continuous Memory Diagnostic Trouble Codes (CMDTCs).
8. Carry out the on-demand self-test diagnostics from the PCM, HVAC module - EMTC or HVAC module - DATC and retrieve continuous DTCs for the HVAC module - EMTC or HVAC module - DATC.
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 any HVAC module - DATC DTCs retrieved are related to the concern, go to the HVAC Module - Dual Automatic Temperature Control (DATC) DTC Chart HVAC Module - Dual Automatic Temperature Control (DATC) DTC Chart. If any HVAC module - EMTC DTCs retrieved are related to the concern, go to the HVAC Module - Electronic Manual Temperature Control (EMTC) DTC Chart HVAC Module - Electronic Manual Temperature Control (EMTC) DTC Chart. If the PCM DTCs retrieved are related to the concern, go to the PCM DTC Chart PCM DTC Chart. For all other DTCs, refer to Multifunction Electronic Modules Diagnostic Trouble Code (DTC) Chart
10. If no DTCs related to the concern are retrieved, GO to Symptom Chart - Climate Control Systems. Symptom Chart - Climate Control Systems