HVAC Pre-Diagnostic Troubleshooting Procedure: Notes

WARNING: This page is about a different car, the 2011 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Perform the following steps prior to any diagnostic procedure(s).

Testing should only be performed with the battery fully charged to avoid false diagnosis.
With the scan tool, read Powertrain Control Module (PCM) DTCs. If PCM DTCs are present, and perform the appropriate diagnostic procedure(s) before proceeding. Refer to appropriate Electrical Diagnostic Information .
With the scan tool, read Totally Integrated Power Module (TIPM) DTCs. If TIPM DTCs are present, and perform the appropriate diagnostic procedure(s) first before proceeding. Refer to appropriate Electrical Diagnostic Information .
With the scan tool, read HVAC DTCs. Record all Stored, Active, and Pending DTC information.
With the scan tool, read the Environmental Data. Use this data to identify the conditions in which the DTC was set.
Refer to the When Monitored and Set Conditions for this DTC. DTCs can set at ignition on, at start up, or operating under specific conditions.
Using the wiring diagram as a guide, inspect the wiring and connectors related to this circuit and clean/repair as necessary.
Check for controller software updates. Some conditions can be corrected by upgrading the controller software.

NOTE:

If the controller is updated with new software, with the scan tool, perform a HVAC Actuator Calibration Test.

Check for Service Information Tune-ups or Service Bulletins for any possible causes that may apply.