Unless directed otherwise, the ignition must be OFF with the key removed, and all
electrical loads must be OFF before servicing any electrical component. Disconnect
the negative battery cable to prevent an electrical spark should a tool or equipment
come in contact with an exposed electrical terminal. Failure to follow these
precautions may result in personal injury and/or damage to the vehicle or its
components.
For Vehicles equipped with OnStar® (UE1) with Back Up Battery:The Back Up
Battery is a redundant power supply to allow limited OnStar® functionality in the
event of a main vehicle battery power disruption to the VCIM (OnStar®module). Do
not disconnect the main vehicle battery or remove the OnStar® fuse with the
ignition key in any position other than OFF. Retained accessory power should be
allowed to time out or be disabled (simply opening the driver door should disable
retained accessory power) before disconnecting power. Disconnecting power to the
OnStar® module in any way while the ignition is On or with retained accessory
power activated may cause activation of the OnStar® Back-Up Battery system and
will discharge and permanently damage the back-up battery. Once the Back-Up
Battery is activated it will stay on until it has completely discharged. The back-up
battery is not rechargeable and once activated the back-up battery must be
replaced.
