in2pro

Body Controls - BCM Cross Platform Functionality

INFORMATION
Bulletin No.: 09-08-47-002
Date: November 17, 2009
Subject: Information on Body Control Module (BCM) Functionality Across Vehicle Lines
Models:
2004-2010 Chevrolet Malibu
2008 Chevrolet Malibu Classic
2005-2010 Chevrolet Cobalt
2006-2010 Chevrolet HHR
2005-2009 Pontiac G6
2006-2009 Pontiac Solstice
2007-2009 Saturn AURA, SKY
The purpose of this bulletin is to address the unique differences in Body Control Module (BCM) functionality of the affected vehicles. Many electrical functions on these vehicles do not directly involve the BCM, even though they may on other vehicles. The cooling fans, for example, are controlled by the engine control module (ECM) on the Malibu, but are controlled by the BCM on the Impala. The BCM is primarily a gateway between the high- and low-speed GMLAN serial data buses on the above listed vehicles.
Functions That Do Not Involve the BCM
The following list of features and functions are not controlled or dependent on the BCM:
Important
The BCM should NOT be replaced for conditions in these areas.
- Cooling fans
- Clock display
- Radio display
- Power mirrors
- OnStar(R)
- Rear wiper (on Malibu Maxx)
- Warning lamps
- Malfunction indicator lamp (MIL)
- Driver seat belt reminder light and chime
- Power windows
Important
The BCM also acts as a power distribution center and may provide a fused battery feed to the modules that actually do control the above functions.
Do not assume a similar control module issue will apply to different vehicle lines. Refer to SI for the appropriate description and operation and diagnostic information.