Collision Prevention Assist Controller Unit, Component Description - GF30.30-P-3214RDM

Model 172.4 

as of model year 2017 

with code 258 (COLLISION PREVENTION ASSIST) 

Show on model 172.4 

Location 

The COLLISION PREVENTION ASSIST controller unit is located in the direction of travel at the rear right to the radiator trim.

Tasks 

The COLLISION PREVENTION ASSIST controller unit detects obstacles and vehicles ahead and warns the driver about a possible collision.

If the COLLISION PREVENTION ASSIST controller unit detects a 1 risk of collision, it initiates autonomous brake application.

This results in the following tasks for the COLLISION PREVENTION ASSIST controller unit:

• Reading in input factors 
• Evaluation of input factors 
• Transmission of initial parameters 

Reading in input factors 

The COLLISION PREVENTION ASSIST controller unit receives the following input factors, among other things, via chassis CAN 1 (CAN E1):

• Wheel speed and wheel rotation direction
• Acceleration/yaw rate
• Steering wheel angle
• Accelerator pedal position
• Brake pedal position
• Position of combination switch (S4)
• Driver request via menu settings in the instrument cluster (A1)

The resulting functions are described in the respective function descriptions (see also block diagram or function schematic).

Evaluation of input factors 

The integrated microprocessor evaluates the input factors.

Transmission of initial parameters 

The COLLISION PREVENTION ASSIST controller unit also transmits the following initial parameters via chassis CAN 1:

• Requests to output optical and acoustic warning messages in instrument cluster
• Requirements for initiating PRE-SAFE® measures
• 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).

Body 

The COLLISION PREVENTION ASSIST controller unit includes the following assembly parts:

• Radar sensor
• Control unit

Properties of the radar sensor:

• Detection range of the radar sensor: s = 0 to 80 m for a detection angle of ∠ = 18° ± 8°
• 25 GHz radar sensor operating on the pulse Doppler principle for independent measurement of distance and speed

The COLLISION PREVENTION ASSIST controller unit must be newly adjusted after exchange (e.g. after an accident repair) using the integrated "service adjustment mode".

Wiring diagram for collision warning system control unit

PE30.30-P-2104-97TAA