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PETIE33, ASE Certified Technician
Category: GMC
Satisfied Customers: 390
Experience:  ASE certified technician.Top of graduating class. GM trained on makes and models of GMC.
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GMC Acadia Air Condition is not working.

Customer Question

My GMC Acadia air conditioning switch blinks on when pressed but then goes off. Of course the ac does not work.

Submitted: 8 years ago.
Category: GMC
Expert:  PETIE33 replied 8 years ago.

Generally when the light is flashing on the ac button it means it's not available at this time. This system has parameters that will not let the system run until they have been met like outside temperature, ambient air temperature etc. There is a document that GM has on the ac indicators flashing i will post it below.

#07-01-38-003: Information for Vehicles with HVAC Control Module A/C and Recirculation Indicators Flashing - (Jun 12, 2007)

Subject: Information for Vehicles with HVAC Control Module A/C And Recirculation Indicators Flashing

Models: 2008 Buick Enclave

2007-2008 Cadillac Escalade Models

2006-2007 Chevrolet Monte Carlo

2006-2008 Chevrolet Impala

2007-2008 Chevrolet Avalanche, Equinox, Silverado, Suburban, Tahoe

2007-2008 GMC Acadia, Sierra, Yukon Models

2007-2008 Pontiac Torrent

2008 HUMMER H2

2007-2008 Saturn OUTLOOK

2008 Saturn VUE


Some customers may comment that the Air Conditioning (A/C) indicator on the Heating Ventilation and Air Conditioning (HVAC) Control Module flashes then turns off after they press the A/C button. Others may comment that the Recirculation indicator on the HVAC Control Module flashes then turns off after they press the Recirculation button.

This is normal operation for the HVAC Control Module and indicates that the A/C or Recirculation function is not available at this time.

Reasons that the A/C may not be available (calibrated values vary by program) are listed below. Consult the appropriate vehicle Service Information (SI) for detailed HVAC Description and Operation:

• Ambient Air Temperature is too low (if equipped with Ambient Air Temperature Sensor)

• Vehicle voltage less than 9.5 volts

• Refrigerant Pressure too low

• Refrigerant Pressure too high

Engine Coolant Temperature too high

• Engine is not in RUN

• HVAC Control Head is in the OFF position

Reasons Recirculation may not be available: Mode switch in Floor, Defog or Defrost mode.

The reason(s) A/C is currently disabled can be viewed with a Tech 2® by navigating to HVAC Data display and viewing the "A/C Permission" parameter.

Do not replace the HVAC Control Module for a flashing A/C Indicator or flashing Recirculation Indicator, as this is normal operation.