Diagnostic Test

1. Disconnect all jumper wires and reconnect all previously disconnected components and connectors.
2. Ensure that all accessories are turned off.
3. Ensure that the battery is fully charged. If the battery was disconnected for any reason, refer to (Refer to ELECTRICAL/BATTERY SYSTEM - STANDARD PROCEDURE - BATTERY RECONNECTION) for accessory calibration procedures.
4. If the FCM has been replaced, the Pinion Factor MUST be programmed into the FCM. Refer to the scan tool for program procedure.
5. Turn the ignition on.
6. With the scan tool, record and erase DTCs from all modules.
7. Perform this step only if diagnosing faults related to the HVAC system.
   • The Manual Temperature Control (MTC) is not on the Bus and not addressable with a scan tool. Perform the following to clear DTCs from the MTC: 1. Turn the blower control on. 2. Press the A/C mode switch down, turn the blower control to off, wait three seconds and then release the A/C mode switch. 3. When the A/C status indicator begins flashing DTCs, press the A/C mode switch down for three seconds and then release the switch.
   • For vehicles equipped with Automatic Temperature Control (ATC), if repairs were made to any of the HVAC doors, linkage, door actuators, or door actuator circuits, run the actuator calibration function by selecting the following from the scan tool menu: select HVAC, More Options, System Tests, Actuator Calibration Test, and Start. Follow the directions displayed by the scan tool. Allow the test to run to completion before proceeding.
   • For vehicles equipped with MTC, if repairs were made to any of the HVAC doors, linkage, door actuators, or door actuator circuits, run the actuator calibration function by performing the following: 1. Turn the ignition on. 2. Turn the blower control to off. 3. Press the EBL mode switch down for five seconds and then release it. Wait approximately 90 seconds for the calibration process to run to completion before proceeding.
8. Turn the ignition off, wait 10 seconds, and then turn the ignition on.
9. Operate all functions of the system that caused the original concern.
10. With the scan tool, select ECU View and check for DTCs in the modules.
11. Perform this step only if diagnosing faults related to the MTC HVAC system.
    NOTE: The A/C status indicator displays active DTCs when the EBL status indictor is not illuminated and stored DTCs when the EBL status indicator is illuminated.
    • Perform the following to read DTCs from the MTC: 1. Turn the blower control on. 2. Press the A/C mode switch down, turn the blower control to off, wait three seconds and then release the A/C mode switch. 3. Read the DTCs from the flashing A/C status indicator.

Are DTCs present in any of the modules or is the original condition still present? 

Yes 

1. The repair is not complete. Refer to the related category for the DTC or symptom that is still present.

No 

1. The repair is complete.