Theory Of Operation

The module incorporates a backup battery with a life expectancy of 5-7 years that will allow the emergency call (eCall) to a Public Safety Answering Point (PSAP) system to continue to work in case of vehicle power interruption. The battery will allow call and data transfer for at least 15 minutes with callback capability for at least one hour after a vehicle emergency. The eCall system uses a single dedicated 70mm speaker for vocal communication with the vehicle occupants during an eCall. The speaker is located behind the lower closeout panel to the right of the driver leg.

The system will detect an eCall trigger, whether automatic through a crash severe enough or manual at a vehicle occupant's request by pressing the SOS button. Once triggered, the system will attempt to send an MSD to any public system operated by an MNO and also attempt to establish a voice connection between the vehicle and the PSAP. When connected to the MNO, the vehicle will transfer the vehicle location and VIN.

The system is triggered automatically when the Occupant Restraint Controller (ORC) sends a signal using the Controller Area Network (CAN) - C data bus and / or the Output Digital Serial line. 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 system can be manually triggered using the SOS button by the vehicle driver or a passenger. The 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 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 microcontroller continuously monitors all of the system electrical circuits to determine the system readiness. If the detects a monitored system fault, it sets an active and stored Diagnostic Trouble Code (DTC) and sends electronic messages to the IPC and BCM over the CAN data bus to turn On the indicator. 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.

The hard wired inputs and outputs may be diagnosed using conventional diagnostic tools and procedures. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls and communication between other modules and devices that provide some features of the system. The most reliable, efficient and accurate means to diagnose the electronic controls and communication related to system operation requires the use of a diagnostic scan tool.

For additional details on the description and operation of the system. Refer to MODULE, GLOBAL TELEMATICS BOX, DESCRIPTION AND OPERATION .