MTC

HVAC PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE

For a complete wiring diagram, refer to the Wiring Information .

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, Testing and Inspection Perform the appropriate diagnostic procedure(s) before proceeding.
- With the scan tool, read Totally Integrated Power Module (TIPM) DTCs. If TIPM DTCs are present, Testing and Inspection Perform the appropriate diagnostic procedure(s) first before proceeding.
- 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.

Did any of the above procedures repair the vehicle?

Yes

- Testing is complete.
- Perform HVAC VERIFICATION TEST HVAC Verification Test

No

- Testing and Inspection Perform the appropriate diagnostic procedure.