Accident Data Recorder, Detailed Information - GF54.60-S-0001A

Model 447 

With Code XM7 (MOPF II) 

Courtesy of MERCEDES-BENZ USA

Overview of accident data recorder, shown on model 447.8 with engine M254 

Courtesy of MERCEDES-BENZ USA

Overview of accident data recorder, shown on model 447.6/7 with engine M254 

Courtesy of MERCEDES-BENZ USA

Topology of accident data recorder, shown on model 447.8 with engine M254 

Courtesy of MERCEDES-BENZ USA

Topology of accident data recorder, shown on model 447.6/7 with engine M254 

Overview 

This document contains information on:

• General 
• Function requirements 
• Function 
  • Storage conditions 
  • Structure 
  • Sequence 

General 

The accident data recorder is a system that, in the event of an accident, stores data such as speed, acceleration or condition of the driving systems over a certain period of time following the accident. By doing so, the accident data recorder is able to provide precise data for the reconstruction of how the accident occurred.

Function requirements 

• Circuit 15 ON

Function 

The accident data recorder records the vehicle data continuously, but only saves this data when the sensors register an accident or circumstances that may cause an accident, resulting in a certain activation threshold being exceeded.

Storage conditions 

The data recorded by the accident data recorder is stored when:

• The Supplemental Restraint System (SRS) control unit (N2/5) registers a high speed change in the lateral or longitudinal direction via the left frontal acceleration sensor (B167) and the right frontal acceleration sensor (B167/1).
• When the driver seat belt tensioner squib (R12/1), front passenger seat belt tensioner squib (R12/2) or center front passenger seat belt tensioner squib (R12/34) is triggered
• When the driver's airbag squib (R12/7), front passenger airbag squib (R12/8), left front window airbag squib (R12/14), right front window airbag squib (R12/15), left center window airbag squib (R12/18), right center window airbag squib (R12/19), left rear window airbag squib (R12/22), right rear window airbag squib (R12/23), driver thorax/pelvis side airbag squib (R12/30) or front passenger thorax/pelvis side airbag squib (R12/31) is triggered

Structure 

The accident data recorder is part of the Supplemental Restraint System (SRS) control unit (N2/5) and is therefore connected via the user interface CAN (CAN HMI) to the architecture of the vehicle. The data can be read out via the diagnostics connection (X11).

Sequence 

As soon as the Supplemental Restraint System (SRS) control unit (N2/5) registers an accident, depending on the model and equipment installed, the following data is stored:

• Prior to the accident:
  • Vehicle speed from left front axle rotational speed sensor (L6/1), right front axle rotational speed sensor (L6/2), left rear axle rotational speed sensor (L6/3), right rear axle rotational speed sensor (L6/4) via the Electronic Stability Program (ESP) control unit (N30/4)
  • Status of throttle flap actuator (M16/5) via ME-SFI [ME] control unit (N3/34) (engine M254)
  • Accelerator pedal position from accelerator pedal module (A68) via drivetrain control unit (N127)
  • Status of brake via Electronic Stability Program (ESP) control unit (N30/4)
  • Ignition cycle in the event of a crash (crash signal originating from the supplemental restraint system (SRS) control unit (N2/5))
  • Engine speed from left exhaust camshaft rotational speed sensor (B6/6) via ME-SFI [ME] control unit (N3/34) (engine M254)
  • Activity of ABS and stability control via the Electronic Stability Program (ESP) control unit (N30/4)
  • Steering angle via the steering column tube module (MRM) control unit (N80)
  • Seat belt buckle status of driver and front passenger via driver seat belt buckle restraint system switch (S68/1), front passenger seat belt buckle restraint system switch (S68/2) and center front passenger seat belt buckle restraint system switch (S68/5)
  • Airbag warning lamp via instrument cluster (A1) (model 447.6/7) or instrument cluster control unit (N133/1) (model 447.8)
  • Trigger time of driver's airbag and front passenger airbag via driver's airbag squib (R12/7) and front passenger airbag squib (R12/8)
• After the accident:
  • Change in speed in longitudinal and lateral direction via left frontal acceleration sensor (B167) and right frontal acceleration sensor (B167/1)

	Detailed information
	Overall network (GVN), detailed information	Model 447 except electric vehicles with code XM7 (Facelift II)	GF00.19-S-0020-01B