Seat Belt Control Module: Description and Operation

GF91.60-P-4048TX Restraint Systems Control Unit, Component Description

Component Identification:

Location
The restraint systems control unit is located on the center tunnel in front of the selector lever module.

Task
The restraint systems control unit is used to provide passive interior protection. The restraint systems control unit deploys the restraint systems in the event of an accident. These include the airbags, the emergency tensioning retractors, and the belt force limiters. The restraint systems control unit has self-monitoring and fault monitoring features. Head-on, rear-end, and side impact collisions are recorded, and a distinction is made between the different types of collision.
Roll-overs around the longitudinal vehicle axis can also be detected. A maximum of 16 restraint systems can be actuated.

The restraint systems control unit has an integrated rollover sensor. Operations on or with the connected restraint systems control unit may only be performed if the transmitter key (A8/1) is removed, otherwise there is a danger that the airbag will be deployed erroneously.

Scope of task
^ Collision recognition and ignition timing determination.
^ Ignition stage triggering when collision occurs
^ Monitoring the seat occupied and automatic child seat recognition of the front passenger seat.
^ Storing non-volatile crash telegrams.
^ Voltage supply of the driver-side frontal acceleration sensor (B48/1), the passenger-side frontal acceleration sensor (B48/2), the driver sidebag and windowbag sensor (A53/1), and the front passenger sidebag and windowbag sensor (A54/1).
^ Capacitor in the event of battery disconnection if a collision occurs.
^ Self-testing and permanent monitoring of system and fault display with non-volatile storage of faults and down times.
^ Programmability with regard to equipment and crash parameters.
^ Fault output via the diagnosis communication
^ System readiness display via Controller Area Network bus class B (interior) (CAN-B) to the instrument cluster (A1).
^ Actuation of the digital crash output via CAN-B (in (United States Of America) vehicles the digital crash output is actuated separately).

Discrete inputs
^ Circuit 31
^ Circuit 15
^ Circuit 15R
^ Front passenger seat occupancy and automatic child seat recognition (B48) (not (United States Of America), except (United States Of America) up to 31.5.05 standard equipment, as of 1.6.05 with code (U18) Automatic child seat recognition (ACSR [AKSE])
^ Front passenger seat occupied recognition (B41/1) (as of 1.6.05 without code (U18) Automatic child seat recognition (ACSR [AKSE])
^ Driver sidebag and windowbag sensor
^ Passenger-side sidebag and windowbag sensor
^ Driver-side frontal acceleration sensor
^ Passenger-side frontal acceleration sensor
^ Driver side seat belt buckle restraint systems switch (S68/3)
^ Front passenger-side seat belt buckle restraint systems switch (S68/4)

Discrete inputs and outputs
^ Driver airbag squib 1 (R12/13)
^ Driver airbag squib 2 (R12/14)
^ Passenger airbag squib 1 (R12/4)
^ Passenger airbag squib 2 (R12/5)
^ Driver sidebag squib (R12/9)
^ Front passenger sidebag squib (R12/10)
^ Left rear sidebag squib (R12/11) (with code (293) Left and right rear sidebag)
^ Right rear sidebag squib (R12/12) (with code (293) Left and right rear sidebag)
^ Left front windowbag squib (R12/16)
^ Right front windowbag squib (R12/17)
^ Driver ETR [GUS] squib (R12/1)
^ Passenger ETR squib (R12/2)
^ Left rear ETR squib (R12/6)
^ Right rear ETR squib (R12/7)
^ Driver belt force limiter (R12/27)
^ Front passenger belt force limiter (R12/26)

Discrete outputs:
^ Digital crash output of the emergency call system control unit (N123/4) (only (United States Of America))

Controller Area Network (data bus/CAN bus) (CAN) signals:
The restraint systems control unit is a CAN-B subscriber.