Supplemental restraint system (SRS), function (MODEL 204.0 /2 as of model year 2009 /YoM 08, MODEL 204.3, 204.9) - GF91.60-P-0002CE

MODEL 204.0 /2 as of model year 2009 /YoM 08

MODEL 204.3

MODEL 204.9

Fig 1: Identifying Supplemental Restraint System (SRS) Function Diagram

Courtesy of MERCEDES-BENZ USA

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)
Circuit 15R ON

The electronic ignition lock control unit transmits the circuit status of circuit 15 over chassis CAN.

Supplemental restraint system, general

The supplemental restraint system is used to protect occupants in the event of a crash.

The supplemental restraint system includes the following subfunctions:

Function sequence system monitoring
Function sequence power reserve
Function sequence belt lock system

The following partial functions are described in separate documents:

Passenger-side seat occupied recognition function (without code (U10) Front passenger seat with weight detection)
Passenger side seat occupied recognition function (on model 204.0/3/9 with code (U10) Front passenger seat with weight sensing)
Deploy supplemental restraint system, function
Pedestrian protection function (on model 204.3 with code (U60) Pedestrian protection)

Function sequence system monitoring

The supplemental restraint system (SRS) continuously monitors itself and notifies the driver of any system faults via the supplemental restraint system indicator lamp (A1e15) in the instrument cluster. The automatic child seat recognition warning lamp is also switched on. Any faults are stored in the nonvolatile memory of the supplemental restraint system control unit. The supplemental restraint system indicator lamp and the automatic child seat recognition warning lamp are switched off following a successful self-test after t = 4 s.

Function sequence power reserve

The supplemental restraint system control unit provides a power reserve for at least t = 300 ms if the battery has been disconnected.

Function sequence belt lock system

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

Passenger-side seat occupied recognition function	Without code (U10) Front passenger seat with weight detection	GF91.60-P-1100CE
Passenger-side seat occupied recognition function	On model 204.0/3/9 with code (U10) Front passenger seat with weight sensing	GF91.60-P-1100CEU
Deploy supplemental restraint system, function		GF91.60-P-2001CE
Pedestrian protection function	On model 204.3 with code (U60) Pedestrian protection	GF91.60-P-1005CE