Circuit/System Verification

WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON, compare the scan tool BCM Prev. State of Charge and Start Up State of Charge parameters. The scan tool readings should not differ by greater than 30 percent.

If the readings differ by greater than 30 percent, refer to Battery Electrical Drain/Parasitic Load Test .