Inspection and Verification
Climate Control System
Inspection and Verification
NOTE: Verify the service disconnect plug is correctly inserted and locked into the LOCK position.
1. Verify the customer concern.
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 power and ground from the DLC (Data Link Connector) are provided to the VCM (Vehicle Communication Module).
If the scan tool does not communication 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 power to the VCM (Vehicle Communication Module).
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 HVAC module, Air Conditioning Compressor Module (ACCM) , Instrument Panel Cluster (IPC) or 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 for the HVAC, ACCM (Air Conditioning Compressor Module) , IPC (Instrument Panel Cluster) or PCM.
9. If the HVAC DTCs retrieved are related to the concern, go to the HVAC Module DTC Chart. If the ACCM (Air Conditioning Compressor Module) DTCs retrieved are related to the concern, go to the Air Conditioning Compressor Module (ACCM) 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. Heating and Air Conditioning
NOTE: If no DTCs are present, GO to Symptom Chart - Climate Control Systems for the appropriate diagnostic action. Symptom Related Diagnostic Procedures
HVAC Module and A/C Compressor Self-Test
During the self-test, the HVAC module will do the following:
- command airflow to PANEL vents
- command temperature blend door actuator to full cold
- set blower speed to level 4 and the 4th level will be displayed on the display
- illuminate the POWER, A/C and RECIRC button indicators
- flash the DEFROST, AUTO and rear window defrost button indicators
- command the A/C compressor to between 1,900 and 2,000 rpm
1. Start the engine.
2. Observe the Electric A/C Compressor Speed (ACCM_ECS) Air Conditioning Compressor Module (ACCM) PID.
3. At the same time, press and release the POWER and DEFROST buttons then, within 2 seconds, press the RECIRC button.
4. Observe the HVAC module actions and A/C compressor speed.
5. To exit the self-test, press any climate control button or turn the ignition OFF.
- If the blower is inoperative, GO to Pinpoint Test K. Pinpoint Test K: Incorrect/Erratic Direction of Airflow From Outlets
- If the blower speed is incorrect, GO to Pinpoint Test L. Pinpoint Test L: Insufficient, Erratic or No Heat
- If one or more indicators do not illuminate but the HVAC and A/C compressor operate correctly, INSTALL a new Front Controls Interface Module (FCIM).
- If the ACCM_ECS PID reads 0 RPM, GO to Pinpoint Test I. Pinpoint Test I: Unable to Duplicate the Customer Concern and No DTCs Present
- If the ACCM_ECS PID reads between 1 and 1,899 rpm or greater than 2,000 rpm, INSTALL a new electric A/C compressor. TEST the system for normal operation.
- If all modes in the self-test are achieved, GO to Pinpoint Test E. Pinpoint Test E: DTCs B1A68:11 and 15