12 Volt Battery Connect
On vehicles equipped with the high voltage system, disconnecting the 12-volt battery negative cable alone will not power down the 12-volt system. You must perform the 12-volt Power Down procedure before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
The high voltage battery on this vehicle is used to charge the 12 volt battery through the Integrated Dual Charging Module (IDCM). Therefore, disconnecting the 12 volt cables may not completely power down the 12 volt system. The high voltage battery should be powered down also to prevent the possibility of the high voltage system generating voltage into the low voltage system. The high voltage battery power up procedure includes connecting the 12v battery and powering up of the 12 volt system. Perform the HIGH VOLTAGE POWER UP PROCEDURE to connect and power up the 12 volt system. Refer to ELECTRICAL/BATTERY SYSTEM/STANDARD PROCEDURE .