Excessive Cabin Moisture / Reduced Window Clearing, Non Responsive HVAC Control (Reprogram HVAC System Control Module) (11-01-38-001B)

Publication date: 2011-02-28
Reference number: 11-01-38-001B
Supersedes refnos: 11-01-38-001

EXCESSIVE CABIN MOISTURE / REDUCED WINDOW CLEARING, NON RESPONSIVE HVAC CONTROL (REPROGRAM HVAC SYSTEM CONTROL MODULE)

TECHNICAL SERVICE BULLETIN

Reference Number(s): 11-01-38-001B, Date of Issue: July 20, 2011

Affected Model(s):	2010-2011 Chevrolet Avalanche, Silverado, Suburban, Tahoe; 2010-2011 GMC Sierra, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL; All with Manual Air Conditioning (RPO CJ3 or C67); Vehicles Built Prior to March 14, 2011
Supercedes:	This bulletin is being revised to add build date information. Please discard Corporate Bulletin Number 11-01-38-001A (Section 01 - HVAC).

Superceded Bulletin(s): 11-01-38-001A

CONDITION #1

In rare cases, some customers may comment of excessive cabin moisture or difficulty keeping the windows clear in low ambient temperatures.

CAUSE #1

This concern may be caused by the recirculation door being in the recirculation position while the mode is set to a floor through defrost position.

CONDITION #2

Some customers may comment that the HVAC temperature or mode does not change to the current HVAC control setting at start up. If the HVAC temperature or mode controls are changed, then the doors will move to the correct position. There will be no DTCs set.

CAUSE #2

This condition may be caused by changing the HVAC temperature or mode controls while the ignition key is turned off or immediately before turning the key off.

CORRECTION FOR CONDITION #1 AND #2

IMPORTANT: DO NOT replace the HVAC control module for this concern.

Revised software has been developed to address both conditions.

Technicians are to reprogram the HVAC control module using the Service Programming System (SPS) with the latest software currently available in TIS2WEB.

When using a Tech 2® or a Multiple Diagnostic Interface (MDI) for reprogramming, ensure that it is updated with the latest software version.

During programming, the battery voltage must be maintained within the proper range of 12-15 Volts. Only use the approved Midtronics® PSC 550 Battery Maintainer (SPS Programming Support Tool EL-49642) or equivalent during programming.

WARRANTY INFORMATION

For vehicles repaired under warranty, use:

Warranty Information

Labor Operation	Description	Labor Time
D4707	HVAC System Control Module Reprogramming with SPS	Use Published Labor Operation Time