Supplemental Restraint System Control Unit, Basic Function - GF91.60-P-9890A

Model All (4xWD, CAR) 

Example illustration of Supplemental Restraint System (SRS) control unit 

Courtesy of MERCEDES-BENZ USA

Overview 

This document contains information on:

• General information 
• Function 

General information 

The SRS control unit controls various passive safety functions. It is defined by evaluating the signals from various sensors on the type and the severity of accident events.

Function 

The SRS control unit is connected to the vehicle's network architecture.

On vehicles with automatic front passenger airbag shutoff, the SRS control unit is also used for data exchange between the Weight Sensing System (WSS) control unit and the appropriate control units.

To implement these tasks, the SRS control unit also processes the following information:

• Circuit status
• Acceleration values
• Pressure values in the doors
• Front passenger seat occupied status
• Seat belt buckle status
• Status of collision recognition (vehicles with radar-supported traffic area monitoring)
• Seat position (Canada version USA version)
• Front bumper pressure values, (vehicles with active hood (pedestrian protection))

The SRS control unit analyzes the accident event and decides the extent to which and time at which restraint equipment is triggered. The restraint equipment is triggered via the squibs each time. The SRS control unit then starts additional functions by sending the crash signal, e.g. hazard warning light system.

An acceleration sensor is integrated into the SRS control unit. This provides information on the vehicle's natural dynamics.

The SRS control unit also sends the following information:

• Crash signal
• Display fault messages request
• Status of front seat belt buckles
• Information on the vehicle's natural dynamics
  • Turn rate
  • Lateral acceleration
  • Longitudinal acceleration

	Component descriptions
	Supplemental restraint system control unit, component description	Model 223	GF91.60-P-4080A
		Model 243	GF91.60-P-4080B
		Model 206	GF91.60-P-4080C
		Model 297	GF91.60-P-4080D
		Model 295	GF91.60-P-4080E
		Model 232	GF91.60-P-4080F
		Model 296	GF91.60-P-4080G
		Model 254	GF91.60-P-4080H
		Model 464	GF91.60-P-4080J
		Model 214	GF91.60-P-4080K
		Model 294	GF91.60-P-4080N
		Model 192	GF91.60-P-4080R
		Model 236	GF91.60-P-4080S