Supplemental restraint system (SRS), function - GF91.60-P-0002R: Notes

MODEL 230 

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

Function 

The supplemental restraint system serves passive occupant safety.

The following events 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 records the acceleration values and controls, depending on the threshold value, actuation of the restraint devices. For evaluation purposes the following sensors are read in:

• Driver-side frontal acceleration sensor (B48/1)
• Passenger-side frontal acceleration sensor (B48/2)
• Left sidebag sensor (A53)
• Right sidebag sensor (A54)

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
• Front passenger seat occupation status

In the event of an accident, and depending on the type and severity of the accident, the following restraint devices are actuated:

• Driver airbag unit, 2-stage
• Front passenger airbag unit, 2-stage
• Left front sidebag unit
• Right front sidebag unit
• Driver emergency tensioning retractor unit
• Front passenger emergency tensioning retractor unit
• Seat belt lock system
• Knee bag unit

  (for vehicles with code (494) USA version)

Capacitor 

The supplemental restraint system is equipped with a capacitor in the restraint systems control unit. If the battery is disconnected, then the voltage supply is assured for at least 150 ms.

Central locking emergency opening 

A crash sensor is installed into the PSE control unit (combined) (A37). Vehicle deceleration values in excess of 6 g cause the emergency opening function to be actuated. Following a waiting time of approx. 8 to 11 s, the pneumatic control unit releases all vehicle doors. Apart from this, the trunk lid release is enabled.

Hazard warning flashers 

In the event of a crash, the hazard warning system is switched on automatically. It can be switched off using the hazard warning system switch (S6/5s1).

Automatic emergency call (for code (494) USA version) 

An automatic emergency call is transmitted following a rollover incident or an airbag activation.

The emergency call is sent by the following control unit:

• E-call control unit (A35/8) (for code (349) E Call emergency call system)
• Emergency call system control unit (N123/4) (for code (359) TELE AID emergency call system)

System monitoring 

The supplemental restraint system monitors itself constantly and signals faults over the left multifunction display (A1p13) and over the right multifunction display (A1p15) in the instrument cluster (A1) to the driver.

The airbag indicator and warning lamp (A1e15) in the instrument cluster is also switched on. Faults are stored in the nonvolatile memory of the restraint systems control unit.

Variant comparison 

During the variant comparison a check is made as to whether the vehicle-specific data, which are sent to the restraint systems control unit, match the data filed in the EIS [EZS] control unit (N73) (up to 31.10.03) or the central gateway control unit (N93) (as from 1.11.03).

	Supplemental restraint system (SRS), location of components		GF91.60-P-0002-01R
	Supplemental restraint system (SRS), component networking	On vehicles without code (494) USA version	GF91.60-P-0002-02R
		On vehicles with code (494) USA version	GF91.60-P-0002-02RA
	Supplemental restraint system (SRS), block diagram	On vehicles without code (494) USA version	GF91.60-P-0002-03R
		On vehicles with code (494) USA version	GF91.60-P-0002-03RA
	Passenger-side seat occupied recognition function	On vehicles without code (494) USA version, on vehicles with code (494) USA version up to 28.2.06	GF91.60-P-1100R
		On vehicles with code (494) USA version as from 1.3.06	GF91.60-P-1100RA
	Seat belt lock system function		GF91.40-P-2001R
	Rear end collision, function		GF91.60-P-2004R
	Side impact, function		GF91.60-P-2005R
	Head-on collision, function		GF91.60-P-2006R
	Rollover process function		GF91.60-P-2007R