Passenger-side seat occupied recognition function - GF91.60-P-1100FQU

MODEL 218 with CODE U10 (Front passenger seat with weight sensor) 

Function requirements, general 

• Circuit 15R ON

The status of circuit 15 is sent to the supplemental restraint system control unit (N2/10) by the electronic ignition lock control unit (N73) via chassis CAN (CAN E) (up to 28.02.2013) or chassis CAN 1 (CAN E1) (as of 01.03.2013).

Passenger-side seat occupied recognition, general 

The passenger-side seat occupied recognition detects whether the front passenger seat is occupied.

The passenger-side seat occupied recognition function includes 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 by a person or a child seat is determined by the weight, which is applied to the front passenger seat.

Up to 30.11.2011: 

The seat occupied recognition pressure sensor (B48/4) measures the pressure in a seat mat filled with silicone. The force that is introduced via the seat belt is measured by the belt tension sensor (B48/3) so that weight classification corrections can be made if necessary. These two measured values are used by the weight sensing system (WSS) control unit (N110) to classify the weight on the seat. The WSS control unit sends the status of the seat occupied recognition via interior CAN (CAN B), front SAM control unit with fuse and relay module (N10/1) and chassis CAN to the supplemental restraint system control unit.

As of 01.12.2011: 

The WSS control unit measures the pressure in a seat mat filled with silicone. The force that is introduced via the seat belt is measured by the belt tension sensor so that weight classification corrections can be made if necessary. Classification of the weight that is present is carried out by the WSS control unit using these two measurements. The status of the seat occupied recognition is sent by the WSS control unit to the supplemental restraint system control unit over the seat occupied recognition LIN (LIN E2).

The following conditions are defined depending on the weight classification:

• Seat not occupied
• Seat occupied:
  • Light weight (e.g. child seat)
  • Person recognized

Additional function requirement for issuing status and fault messages 

• Indicator lamp self-test completed successfully

Information about the indicator lamp self-test can be found in the subfunction "supplemental restraint system triggering function" in chapter "System monitoring".

Function sequence for outputting status and fault messages 

The occupancy status of the front passenger seat is shown as follows:

• Front passenger seat occupied (front passenger airbag activated):

  Automatic child seat recognition airbag OFF indicator lamp (N72/1e1) in upper control panel control unit (N72/1) does not light up.

• Front passenger seat not occupied or child seat detected (front passenger airbag inactive):

  Automatic child seat recognition airbag OFF indicator lamp lights up continuously.

The Supplemental Restraint System control unit sends the request for switching the automatic child seat recognition airbag OFF indicator lamp on or off via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the front SAM control unit. The front SAM control unit actuates the automatic child seat recognition airbag OFF indicator lamp correspondingly via the instrument panel LIN (LIN 1).

Fault messages: 

If faults or malfunctions of the seat occupied recognition occur, the following indicator lamps are switched on:

• Supplemental restraint system indicator lamp (A1e15) in the instrument cluster
• Automatic child seat recognition airbag OFF indicator lamp

A fault code is also stored in the supplemental restraint system control unit and a correspondent message is shown on the multifunction display (A1p13) of the instrument cluster.

The request to display a corresponding message is sent by the Supplemental Restraint System control unit on vehicles up to 28.02.2013 via the chassis CAN or on vehicles as of 01.03.2013 via the chassis CAN 1, front SAM control unit, and chassis CAN 2 (CAN E2) to the instrument cluster.

	Actuate supplemental restraint system, electrical function schematic	MODEL 218 up to model year 2014 with CODE U10 (Front passenger seat with weight sensor)	PE91.60-P-2055-97XAA
		MODEL 218 as of model year 2014 with CODE U10 (Front passenger seat with weight sensor)	PE91.60-P-2055-97XAB
	Overview of system components for supplemental restraint system		GF91.60-P-9996FQ