Passenger-side seat occupied recognition function (except CODE (U10) Front passenger seat with weight sensing) - GF91.60-P-1100CE

MODEL 204.0 /2 as of model year 2009 except CODE (U10) Front passenger seat with weight sensing /YoM 08 

MODEL 204.3 except CODE (U10) Front passenger seat with weight sensing 

MODEL 204.9 except CODE (U10) Front passenger seat with weight sensing 

Function requirements, general 

• Circuit 15R ON

Passenger-side seat occupied recognition, general 

The supplemental restraint system detects whether the front passenger seat is occupied or not. With code (U18) Automatic child seat recognition (ACSR [AKSE]) a fitted child seat is also detected.

The automatic child seat recognition is only guaranteed to work with a child seat that has been approved and coded by Mercedes-Benz. This child seat must be equipped with two transponders (resonators), which are located at the left and right in its base.

The passenger-side seat occupied recognition consists of the following subfunctions:

• Function sequence for front passenger seat occupied recognition 
• Function sequence for outputting status and fault messages 

Function sequence for front passenger seat occupied recognition 

Occupation of the front passenger seat is detected by the front passenger seat occupied recognition (B41/1) (without code (U18) Automatic child seat recognition (ACSR [AKSE])).

The seat occupied recognition and front passenger seat ACSR [AKSE] (B48) (with code (U18) Automatic child seat recognition (front passenger seat)) detects whether the front passenger seat is occupied by a person or a child seat. The signals are forwarded in each case to the supplemental restraint system control unit (N2/10).

The seat occupation status is read in via a direct line on model 204.0/2/9 up to 28.2.11 and on model 204.3. On model 204.0/2/9 as of 1.3.11, data transfer takes place via the seat occupation LIN (LIN E2).

The following situations are defined:

• Seat unoccupied:

  If the seat belt is not buckled, the front passenger airbag unit, front passenger sidebag unit and front passenger emergency tensioning retractor unit are disabled.

  If the seat belt is buckled, the front passenger airbag unit is switched off.

• Seat occupied (light or heavy person):

  The front passenger airbag unit is enabled (ignition of first stage or both stages).

• Child seat detected (with code (U18) Automatic child seat recognition (ACSR [AKSE])):

  The front passenger airbag unit is switched off.

Function sequence for outputting status and fault messages 

The output of status and fault messages consists of the following subfunctions:

• Function sequence for actuation of automatic child seat recognition warning lamp (S6/1e1) (model 204.9, model 204.0/2 up to 28.2.11) 
• Function sequence for actuation of automatic child seat recognition airbag off indicator lamp (N72/1e1) (model 204.3, model 204.0/2 as of 1.3.11) 
• Function sequence for outputting fault messages 

Function sequence for actuation of automatic child seat recognition warning lamp (model 204.9, model 204.0/2 up to 28.2.11) 

The signal for switching the automatic child seat recognition warning lamp on or off is sent by the supplemental restraint system control unit via chassis CAN (CAN E) to the front SAM control unit with fuse and relay module (N10/1). This switches the automatic child seat recognition warning lamp on or off over the instrument panel LIN (LIN 1).

Function sequence for actuation of automatic child seat recognition airbag off indicator lamp (model 204.3, model 204.0/2 as of 1.3.11) 

The signal to switch the automatic child seat recognition airbag OFF indicator lamp on or off is sent by the supplemental restraint system control unit via chassis CAN to the front SAM control unit. It switches the automatic child seat recognition airbag off indicator lamp on or off via instrument panel LIN.

Function sequence for outputting fault messages 

If the seat occupied and automatic child seat recognition sensor is defective or communication with the supplemental restraint system control unit is interrupted (e.g. plug not connected), the automatic child seat recognition warning lamp is also switched on. A fault is also stored in the supplemental restraint system control unit and a corresponding message show on the multifunction display (A1p13) of the instrument cluster (A1).

If the child seat is defective or improperly positioned (only one resonator detected), the supplemental restraint system warning lamp (A1e15) in the instrument cluster and the automatic child seat recognition warning lamp are switched on.

Overview of supplemental restraint system (SRS) system components

GF91.60-P-9998CE