HVAC Pre-Diagnostic Troubleshooting Procedure: Notes

WARNING: This page is about a different car, the 2012 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) DTC's. If PCM DTC's are present, Refer to 3.7L/4.7L/5.7L - DIAGNOSTIC CODE INDEX - NGC - 1500 & 2500 or 6.7L - DIAGNOSTIC CODE INDEX - 2500 & 3500 and perform the appropriate diagnostic procedure(s) before proceeding.
With the scan tool, read Totally Integrated Power Module (TIPM) DTC's. If TIPM DTC's are present, and perform the appropriate diagnostic procedure(s) first before proceeding. Refer to TIPM - DIAGNOSIS AND TESTING .
With the scan tool, read HVAC DTC's. 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. DTC's 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.