K 1500 Truck 4WD V8-4.8L VIN V (2003)
run flag serial data is true, indicating that the engine is running, the modules fail-safe to "Run". In this state the modules and their subsystems can
support all operator requirements. If the engine run flag serial data is false, indicating that the engine is not running, the modules fail-safe to
"OFF-AWAKE". In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local
inputs and serial data inputs from other modules on the vehicle.
Discrete Ignition Signals
Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid BCM message received on the serial data
circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, B+, the
modules will fail-safe to the "RUN" power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to
"OFF-AWAKE". In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local
inputs and serial data inputs from other modules on the vehicle.
