SBM Wake-Up/Sleep State

The SBM is able to control or perform all of the SBM functions in the wake-up state. The SBM enters the sleep state when active control or monitoring of system malfunctions has stopped, and the SBM has become idle again. The SBM must detect certain wake-up inputs before entering the wake-up state. The SBM monitors for these inputs during the sleep state, where the SBM is able to detect switch transitions that cause the two wake-up states, activated or deactivated. Multiple switch wake-ups are needed in order to sense both the insertion and the removal of the ignition key. This would allow the SBM to enter a sleep state when the key is in the ignition.

The SBM will enter a wake-up state if any of the following wake-up inputs are detected:
^ Any activity on the serial data line.
^ Any accessory function.
^ The door handle switch (Class 2 message from the Driver Door Module DDM).
^ The door jamb switch (Class 2 message from the Driver Door Module DDM).
^ Door lock switch open or close (Class 2 message from the Driver Door Module DDM).
^ An RFA signal.
^ Inadvertent Power transition.
^ The key in ignition switch.
^ The park/fog/headlamps are on.
^ The SBM experiences a battery disconnect and reconnection condition.
^ The ignition is turned to RUN.

The wake-up state is the state in which the Body Control Module (SBM) is able to control and/or perform all of its system functions. The sleep state is when the SBM has stopped active control and monitoring of system functions and has become idle again. For the SBM to enter the wake-up state, the SBM must detect certain wake-up conditions. These conditions are called wake-up inputs that cause the SBM to change from a sleep to a wake-up state and begin active control and monitoring. The SBM has the ability to monitor for these wake-up inputs in the sleep state. When in the sleep state, the SBM is able to detect switch transitions (activated or deactivated). Multiple switch wake-ups are needed to sense both insertion and removal of an ignition key from the ignition. This would allow the SBM to enter a sleep state when the key is in the ignition.

The SBM will enter a sleep state when all of the following conditions exist:
^ No activity exists on the serial data line.
^ The ignition switch is in the OFF position.
^ No outputs are commanded.
^ No delay timers are actively counting.
^ No wake-up inputs are present.

If all of these conditions are met, the SBM will enter a low power or sleep condition. This condition would indicate that the SBM, which is the power mode master of the vehicle, must have sent a message to the other systems on the serial data line to stop broadcasting their state of health message.