| 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 |
Condition/Concern
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 |
| • | 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.
Recommendation/Instructions
Do not replace the HVAC Control Module for a flashing A/C Indicator or flashing Recirculation Indicator, as this is normal operation.
