Theory Of Operation

The module incorporates SOS/Emergency Call button LED (Light Emitting Diode) indicators that are wired directly to the inside rearview mirror. The LED indicators represent the module system messaging, status, and user requests over the CAN bus. The module controls the bicolor LED indicators (with GREEN and RED lights). The green light is used to provide updates about the eCall status and the red light is used to notify to the user of module status, self-diagnostic activities, and failures.

The module will detect an eCall trigger, whether automatic through a crash severe enough or manual at a vehicle occupant's request by pressing the SOS/Emergency Call button. The system is triggered automatically when the Occupant Restraint Controller (ORC) sends a signal using the Controller Area Network (CAN) - C data bus. The severity of the crash will determine if an eCall is sent or not. This will include direction of the impact, whether frontal, side, rear or rollover. The module system can be manually triggered using the SOS button by the vehicle driver or a passenger. The module will actuate the system in the same manner as if it had been triggered automatically by the ORC. When eCall is in operation, the Radio audio will be muted and eCall audio will be heard through the eCall speaker.

In the event that the vehicle battery connection is compromised, a backup battery is mounted within the module to ensure the integrity of the system and a continuation of an eCall if the vehicle battery becomes disconnected while a call is in progress. If the backup battery becomes discharged, a message will be indicated in the Instrument Panel Cluster (IPC) and a diagnostic code set in the module. The module continuously monitors all of the module system electrical circuits to determine the system readiness. If the module detects a monitored system fault, it sets an active and stored Diagnostic Trouble Code (DTC) and sends electronic messages to the IPC. An active fault only remains for the duration of the fault, or in some cases for the duration of the current ignition cycle, while a stored fault causes a DTC to be stored in memory by the module.

For additional information regarding the description and operation of the system, refer to MODULE, GLOBAL TELEMATICS BOX, DESCRIPTION and MODULE, GLOBAL TELEMATICS BOX, OPERATION .