GF91.60-P-0002RI Supplemental Restraint System (SRS), Function

GF91.60-P-0002RI Supplemental Restraint System (SRS), Function

Function requirements, general
^ The supplemental restraint system (SRS) must be programmed to the vehicle (left or right-hand drive vehicle, equipment programming and configuration parameters)
^ C. 15R On
^ Circuit 15 On

The status of circuit 15 and circuit 15R is transmitted by the EIS [EZS] control unit (N73) via the interior CAN (CAN B).

Supplemental restraint system, general
The supplemental restraint system is used for occupant protection. Frontal, side-on and rear-end collisions and a rollover along the longitudinal vehicle axis are detected and differentiated. If an accident occurs the relevant airbags and emergency tensioning retractors are triggered depending on the severity of the impact.

The SRS comprises the following subfunctions:
^ System monitoring function sequence
^ Power reserve function sequence
^ Function sequence of additional functions in the event of a crash

Further partial functions are described in separate documents:
^ Front passenger seat occupied recognition function (without code (494) USA version, without code (P99) Special model "AMG Black Series")
^ Passenger-side seat occupied recognition, function (with code (494) USA version)
^ Deploy supplemental restraint system, function
^ Belt lock system function (not with code (P99) Special model "AMG Black Series" without code (494) USA version)

System monitoring function sequence
The supplemental restraint system continuously monitors itself and signals faults to the driver via the airbag indicator and warning lamp (A1e15) in the instrument cluster (A1). The automatic child seat recognition airbag OFF indicator lamp (E16) (not with code (P99) Special model "AMG Black Series", without code (494) USA version) is also switched on. All faults are stored in the nonvolatile memory of the restraint systems control unit (N2/7). The indicator lamps are switched off after t = 4 s following a successful self-test.

Power reserve function sequence
The restraint systems control unit provides backup power in the event of any battery disconnection for the supplemental restraint system for at least t = 150 ms. The following sensors are provided with power for t = 30 ms
- Left sidebag sensor (A53) (not with code (P99) Special model "AMG Black Series" without code (494) USA version)
- Right sidebag sensor (A54) (not with code (P99) Special model "AMG Black Series" without code (494) USA version)
- Driver-side frontal acceleration sensor (B48/1)
- Passenger-side frontal acceleration sensor (B48/2)

Function sequence of additional functions in the event of a crash
The additional functions in the event of a crash comprise the following subfunctions:
^ Function sequence for activation of hazard warning function
^ Function sequence for opening the central locking (CL [ZV])
^ Function sequence for shutting off the engine
^ Function sequence for automatic emergency call (with code (359) TELE AID emergency call system)

In the event of a crash, the interior illumination is switched on. See hereto the separate interior illumination function description.

Function sequence for activation of hazard warning function
The hazard warning function is activated automatically after a crash event has occurred. The crash signal is sent by the restraint systems control unit over the interior CAN to the lower control panel control unit (N72). The lower control panel control unit is used as a flashing master. The hazard warning flashing can be switched off at any time via the hazard warning system switch (S6/5s1).

See hereto the separate function description for the exterior lights.

Function sequence for opening the central locking
The central locking is unlocked automatically after a crash event has occurred. Automatic unlocking is performed on request by the pneumatic controller unit with multifunctions (A37). A crash sensor is integrated in the pneumatic controller unit. After a waiting time of t = 8 s to t = 11 s, the pneumatic controller unit unlocks all the doors.

See hereto the separate function description for the central locking.

Function sequence for shutting off the engine
The engine is shut off automatically after a crash event has occurred. The crash signal is sent by the restraint systems control unit via the interior CAN to the EIS [EZS] control unit. The EIS [EZS] control unit routes the signal via the engine compartment CAN (CAN-C) to the ME-SFI [ME] control unit (N3/10). This then causes the engine to be shut off.

Function sequence for automatic emergency call
An emergency call is made automatically after a crash event has occurred. The crash signal is sent discretely by the restraint systems control unit to the emergency call system control unit (N123/4), which then issues an automatic emergency call.

See hereto the separate function description for the emergency call system.