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Electrical - Battery Goes Dead Overnight

Bulletin No.: 06-06-03-009

Date: October 19, 2006

INFORMATION

Subject:
Diagnostic Information on Battery Draw No Start - Body Control Module, BCM Power Timer

Models:
2006-2007 Buick Lucerne
2006-2007 Cadillac DTS
2006-2007 Chevrolet Impala, Monte Carlo
2007 Cadillac Escalade, Escalade ESV, Escalade EXT, SRX
2007 Chevrolet Avalanche, Equinox, Tahoe, Silverado, Suburban
2007 GMC Sierra, Yukon, Yukon XL, Denali, Denali XL
2007 Pontiac Torrent

When performing normal diagnosis on a battery that has gone dead overnight, a technician may notice that the vehicle has approximately 4.1 amp draw on the system. The draw may be steady or may drop down to a low milliamp reading for 1-2 seconds and then rise back up to the 4.1 amp range. If this amp draw condition is observed, check for aftermarket accessories or an improperly installed GM accessory that is wired into circuit 6815 (orange wire) for courtesy lamps. Anytime aftermarket accessories are installed into the courtesy lamp circuit, it can cause the inadvertent power timer in the body control module (BCM) to keep resetting. The BCM will remain awake and cause the draw of approximately 4.1 amps.

When servicing a vehicle with this concern, back out pin 1 of the connector 2 at the BCM and see if the draw goes away. If the draw goes away, check for an aftermarket accessory (Lojack, non-factory DVD system, alarm, etc.) that is improperly installed in circuit 6815.





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