Circuit/System Description

The main control module for current mode is the Body Control Module (BCM). The ignition switch contact works with low current with many discreet circuits to BCM. BCM logic uses the different positions of the ignition switch to identify the power mode requested by the driver and activates specific discreet signals and data messages for operating different subsystems as necessary. Other modules which have switched voltage inputs may operate in a default mode if the power mode master serial data message does not match what the individual module can detect from its own connections.

The power mode master will activate relays and other direct outputs of the power mode master as needed according to the calculated power mode. Some relays controlled by the BCM are switched ignition voltage outputs that are pass through circuits within the BCM directly from the ignition switch. If these circuits short to ground, the B+ circuit fuse to the ignition switch will open.