Symptom:
*HVAC SYSTEM TEST
POSSIBLE CAUSES
ATTEMPT TO COMMUNICATE WITH THE PCM
CHECK FOR HVAC RELATED DTCS IN THE PCM
CHECK FOR ACTIVE HVAC DTCS AND SYSTEM TEST FAULT MESSAGES
CHECK FOR HVAC RELATED DTCS IN THE PCM
MANUAL A/C SYSTEM TEST
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, attempt to communicate with the Powertrain Control Module
(PCM).
Was the DRBIIIt able to communicate with the PCM?
All
Yes → Go To 2
No → Refer to the communication category for the related symptom(s).
Perform BODY VERIFICATION TEST - VER 1.
2 With the DRBIIIt, read Powertrain Computer DTCs.
Are any HVAC related DTCs present?
All
Yes → Refer to the Powertrain Diagnostic Procedures Manual for the
related symptom(s).
Perform BODY VERIFICATION TEST - VER 1.
No → Go To 3
3 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 DRBIIIt 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 DRBIIIt in HVAC, System Tests, actuate the Actuator Circuit Test.
With the DRBIIIt in HVAC, System Tests, actuate the HVAC Door Recalibration
Test.
Does the DRBIIIt display any HVAC DTCs or System Test fault messages?
All
Yes → Return to the symptom list and choose the symptom(s).
Perform BODY VERIFICATION TEST - VER 1.
No → Go To 4
236
HEATING & A/C