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
a A leak in the vacuum control circuit may occur during acceleration (slow leak), may exist at all times (large leak) and may exist only when specific functions are selected (indicating a leak in that portion of the circuit). The vacuum hoses used in the passenger compartment control circuit are constructed from PVC plastic material. The vacuum hoses used in the engine compartment are constructed of Hytrel(R). Because of the materials used, never pinch the vacuum hoses off during diagnosis to locate a leak. A golf tee can be used as a plug when it is necessary to plug one end of the vacuum hose for leak test purposes.
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 VCM.
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 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 the Continuous Memory Diagnostic Trouble Codes (CMDTCs).
9. Carry out the self-test diagnostics from the PCM 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.
If any of the DATC DTCs retrieved are related to the concern, go to the HVAC Module - Dual Automatic Temperature Control (DATC) DTC Chart. If the PCM DTCs retrieved are related to the concern, go to the PCM DTC Chart. For all other DTCs, refer to Body Control Systems. HVAC Module - Dual Automatic Temperature Control (DATC) DTC Chart PCM DTC Chart
11. If no DTCs related to the concern are retrieved, go to the Symptom Chart - Climate Control Systems or GO to Symptom Chart - NVH. Symptom Chart - Climate Control Systems Symptom Chart - NVH