Serial Data Messages

WARNING: This page is about a different car, the 2002 Chevrolet Monte Carlo, 2002 Chevrolet Impala, 2001 Chevrolet Monte Carlo, and 2001 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

Modules that depend exclusively on serial data messages for power modes stay in state dictated by last valid BCM message until they can check for engine run flag status on serial data circuits. If BCM fails, modules monitor serial data circuit for engine run flag serial data. If engine run flag serial data is true, indicating that engine is running, modules fail-safe to RUN. In this state modules and their subsystems can support all operator requirements. If engine run flag serial data is false, indicating that engine is not running, modules fail-safe to OFF (awake). In this state modules are constantly checking for a change status message on serial data circuits and can respond to both local inputs and serial data inputs from other modules on vehicle.