Supplemental restraint system (SRS), function - GF91.60-P-0002SX

MODEL 216.3, 221.0 /1 up to Model Year 8 

Function requirements 

• 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 30 ON

Function 

The supplemental restraint system is used for passive occupant protection. The following type of accident can be recorded and distinguished:

• Head-on collision
• Rear-end collision
• Side-on collision
• Rolling along the longitudinal vehicle axis

The restraint systems control unit (N2/7) records the acceleration values using its integrated sensor and controls the deployment of the restraints systems accordingly. The following sensors are also read in:

• Driver-side frontal acceleration sensor (B48/1)
• Passenger-side frontal acceleration sensor (B48/2)
• Airbag system driver assist (B48/5)
• Airbag system front passenger assist (B48/6)
• Driver door pressure sensor (B48/7)
• Front passenger door pressure sensor (B48/8)
• Rear door pressure sensor, driver-side (B48/9) (model 221)
• Rear door pressure sensor, passenger-side (B48/10) (model 221)

The following information is also evaluated for recording the situation in the vehicle interior:

• Left front seat belt buckle status
• Right front seat belt buckle status
• Left rear seat belt buckle status (model 221 with code (223) Rear bench seat with electrically adjustable outer seats with PRE-SAFE positioning function for outer seats and outer head restraints)
• Right rear seat belt buckle status (model 221 with code (223) Rear bench seat with electrically adjustable outer seats with PRE-SAFE positioning function for outer seats and outer head restraints)
• Front passenger seat occupancy status (in vehicles as of 1.6.07 and without code (U18) Automatic child seat recognition (ACSR [AKSE]) the front passenger seat occupancy status is only evaluated for the seat belt reminder warning)

In the event of an accident the following restraint systems can be deployed to match the type and severity of accident and situation in the vehicle interior:

• Driver-side belt buckle emergency tensioning retractor
• Passenger-side belt buckle emergency tensioning retractor
• Left rear belt buckle emergency tensioning retractor
• Right rear belt buckle emergency tensioning retractor
• Driver-side crash-active head restraint (model 221 as of 1.9.06)
• Passenger-side crash-active head restraint (model 221 as of 1.9.06)
• Driver airbag unit (two-stage)
• Front passenger airbag unit (two-stage)
• Driver sidebag unit
• Front passenger sidebag unit
• Left rear sidebag unit
• Right rear sidebag unit
• Left windowbag unit
• Right windowbag unit
• Driver kneebag unit (model 216 only )

The following interventions are also initiated by the restraint systems control unit:

• Engine shutoff
• Door lock unlocking
• Partial lowering of side windows for pressure compensation and ventilating the vehicle interior
• Partial opening of sliding roof for pressure compensation and to ventilate the vehicle interior (standard in model 216, with model 221 with code (413) Panoramic glass sunroof with top sliding sunroof or with code
• (414) Power glass tilting/sliding sunroof)
• Activation of hazard warning lamp function
• Stationary heater shutoff (for code (228) Stationary heater)
• Placing an emergency call (only )

Capacitor 

The restraint systems control unit provides power reserves for at least 300 ms if the battery has been disconnected.

System monitoring 

The supplemental restraint system continuously monitors itself and indicates any faults over the multifunction display (A1p13) in the instrument cluster (A1) to the driver. The airbag indicator and warning lamp (A1e15) in the instrument cluster is also switched on.

All faults are stored in the nonvolatile memory of the restraint systems control unit.

Seat belt blocking system (model 216) 

Irrespective of the restraint systems control unit, the belt is prevented from extending in certain situations.

	Supplemental restraint system (SRS), location of components	Model 216	GF91.60-P-0002-01SC
		Model 221	GF91.60-P-0002-01SX
	Supplemental restraint system (SRS), component networking	Model 216 without code (494) USA version	GF91.60-P-0002-02SC
		Model 216 with code (494) USA version	GF91.60-P-0002-02SCU
		Model 221 without code (494) USA version	GF91.60-P-0002-02SX
		Model 221 with CODE (494) USA version	GF91.60-P-0002-02SXU
	Supplemental restraint system (SRS), block diagram	Model 216	GF91.60-P-0002-03SC
		Model 221	GF91.60-P-0002-03SX
	Seat belt lock system function	Model 216	GF91.40-P-2001SC
	Passenger-side seat occupied recognition function	Vehicles as of 1.6.07 without code (494) USA version and without code (U18) Automatic child seat recognition (ACSR [AKSE])	GF91.60-P-1100SX
		Vehicles up to 31.5.07 without code (494) USA version, Vehicles as of 1.6.07 without code (494) USA version and with code (U18) Automatic child seat recognition (ACSR [AKSE])	GF91.60-P-1100SXA
		Model 216 with code (494) USA version	GF91.60-P-1100SCU
		Model 221 with CODE (494) USA version	GF91.60-P-1100SXU
	Deploy supplemental restraint system, function		GF91.60-P-2001SX