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

MODEL 166 up to model year 2016 with CODE 252 (COLLISION PREVENTION ASSIST) 

Shows model 166.0 

Fig 1: Collision Prevention Assist Controller Unit Component Location - Model 166 Up To MY 2016 With Code 252

Courtesy of MERCEDES-BENZ USA

Location 

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

Task 

The COLLISION PREVENTION ASSIST controller unit detects obstacles and vehicles driving immediately ahead. Depending on the situations, it initiates a visual or visual/acoustic warning message to warn the driver of a possible collision.

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 speeds and wheel rotation direction
• "Engine running" or "Drivetrain operational" signal.
• Steering wheel angle
• Driver request via menu settings in the instrument cluster (A1)

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

Evaluation of input factors 

The input factors are evaluated by the microprocessor and the corresponding components are actuated.

Transmission of initial parameters 

The COLLISION PREVENTION ASSIST controller unit transmits the following starting data via the chassis CAN 1:

• Requests to output optical and acoustic warning messages in instrument cluster
• Requests for increasing/reducing of the braking torque

The functions that use these signals are described in the individual function descriptions (see appropriate block diagram or function schematic).

Body 

The COLLISION PREVENTION ASSIST controller unit includes the following components:

• 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".