HVAC System Test

*HVAC SYSTEM TEST

For a complete wiring diagram Consult Diagrams/Electrical





Diagnostic Test

1. ATTEMPT TO COMMUNICATE WITH THE PCM
Turn the ignition on.
With the scan tool, attempt to communicate with the Powertrain Control Module (PCM).
Was the scan tool able to communicate with the PCM?

Yes

- Go To2

No

- Refer to the Manufacturer Trouble Codes/Communications for the related procedure(s).
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

2. CHECK FOR HVAC RELATED DTCS IN THE PCM
With the scan tool, read Powertrain Computer DTCs.
Are any HVAC related DTCs present?

Yes

- Diagnose and repair the DTC(s).
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Go To3

3. CHECK FOR ACTIVE HVAC DTCS AND SYSTEM TEST FAULT MESSAGES

NOTE: Active DTCs must be resolved before diagnosing stored DTCs.

NOTE: Anytime a DTC becomes active, or an Actuator Circuit Test fault message is displayed, or a Door Recalibration fault message is displayed, proceed to the conclusion question.

Turn the ignition on.
Turn the mode select control to the panel position.
Verify that the blower motor operates correctly in all speeds. Diagnose and repair all blower related faults before proceeding with this test.
Turn the blower control to the low speed position.
Turn the blend control to the full cold position.
Monitor the scan tool for active HVAC DTCs during the following test steps.
Press the A/C switch on, wait 30 seconds, and then press it off.
Press the EBL switch on, wait 30 seconds, and then press it off.
Slowly turn the blend control from full cold to full hot, wait 30 seconds, and then turn it back to full cold.
Turn the mode select control to every door position. Leave it in each position for approximately 30 seconds.
With the scan tool in HVAC, System Tests, actuate the Actuator Circuit Test.
With the scan tool in HVAC, System Tests, actuate the HVAC Door Recalibration Test.
Does the scan tool display any HVAC DTCs or System Test fault messages?

Yes

- Diagnose and repair the DTC(s).
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Go To4

4. CHECK FOR HVAC RELATED DTCS IN THE PCM
With the scan tool, read PCM DTCs.
Are any HVAC related DTCs present?

Yes

- Diagnose and repair the DTC(s).
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Recheck the climate control system performance.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.