Active Brake Assist Controller Unit, Component Description - GF30.30-S-3222A
Model 447
With Code BA3 (Active Brake Assist System)
With Code XM7 (MOPF II)
Active Brake Assist controller unit, Shown On Model 447.8
The numbers on the pins indicate the pin numbering of the slots.
Active Brake Assist controller unit, Shown On Model 447.8
Overview
This document contains information on:
- General
- Function
- Read-in of input parameters
- Evaluation of input parameters
- Transmission of output parameters
- Structure
General
The Active Brake Assist controller unit (B92) is located centrally at the front behind the bumper.
Function
The Active Brake Assist controller unit (B92) detects obstacles and vehicles ahead and warns the driver of a possible collision.
The Active Brake Assist controller unit (B92) transmits object data for collision-avoidance brake applications to the Electronic Stability Program (ESP) control unit (N30/4).
If the Active Brake Assist controller unit (B92) detects a risk of collision, it initiates autonomous brake application.
This results in the following tasks for the Active Brake Assist controller unit (B92):
- Read-in of input parameters
- Evaluation of input parameters
- Transmission of output parameters
Read-in of input parameters
Read-in of input parameters
The Active Brake Assist controller unit (B92) receives, among other things, the following input parameters via suspension FlexRay (Flex E):
- Wheel speed and wheel rotation direction
- Acceleration/yaw rate
- Steering wheel angle
- Accelerator pedal position
- Brake pedal position
- Switch position of combination switch (S4)
- Driver request via menu settings in the instrument cluster control unit (N133/1), via user interface CAN 2 (CAN HMI2) (model 447.8)
- Driver request via menu settings in the instrument cluster (A1) (model 447.6/7)
The resulting functions are described in the respective function descriptions (see also block diagram or function schematic).
Evaluation of input parameters
The input parameters are evaluated by the microprocessor and the corresponding components are actuated.
Transmission of output parameters
The collision warning system radar sensor transmits the following output parameters via suspension FlexRay (Flex E):
- Requests to output visual and acoustic warning messages in the instrument cluster control unit (N133/1) (model 447.8)
- Requests to output visual and acoustic warning messages in the instrument cluster (A1) (model 447.6/7)
- Requests to initiate PRE-SAFE® measures (with code JP1 (PRE-SAFE®))
- Request to increase the braking torque
- Request for torque reduction
The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).
Structure
The collision warning system radar sensor contains the following components:
- Radar sensor
- Control unit
Properties of the radar sensor:
- Detection range of the radar sensor: s = 0 to 80 m with a detection angle of ∠ = 18° ± 8°
- 25 GHz radar sensor according to the Pulse Doppler Principle for the independent measurement of distance and speed
The collision warning system radar sensor must be readjusted using the integrated "Service Adjustment Mode" after replacement (e.g. after an accident repair).