Subject: Diagnostic information on “Parasitic Battery Draw” with possible “No Start” condition – BCM (Body Control Module) power timer.
Models: 2006 – 07 Buick Lucerne
2006 – 07 Cadillac DTS
2006 – 07 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
Based on GM bulletin: 1868070
When performing a diagnosis on a battery that has gone dead overnight, an installer may notice that the vehicle has approximately 4.1 amp draw on the system. The draw may be steady or may drop to a few millivolts then go back up to 4.1 amps.
This may happen if you install an overhead monitor or other accessory and connect to the orange constant positive power wire in the vehicle’s courtesy light circuit. This will cause the power timer in the BCM to keep re-starting. The BCM will awake and draw 4.1 amps.
This orange wire circuit exits the BCM at pin 1 of connector 2. Cut the wire to test this condition.
Feed your aftermarket accessory in a different fashion.
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