Component Description For Intelligent Radar Sensor Control Unit - GF30.30-P-3305CE

MODEL 204.3 with CODE 234 (Blind Spot Assist)

MODEL 204.9 as of model year 2013 with CODE 234 (Blind Spot Assist)

MODEL 204.0/2 as of model year 2012 with CODE 234 (Blind Spot Assist)

Shown on a disassembled bumper (internal view)

Fig 1: Identifying Intelligent Radar Sensor Control Unit Components

Courtesy of MERCEDES-BENZ USA

Location

The bumper radar sensors at the rear are mounted on the left and right on the inner side of the rear bumper.

Task

The bumper radar sensors detect vehicles in the blind spot via the integrated radar sensor system.

The bumper radar sensors are ultra wideband radar sensors with the following properties:

Radar sensor detection range 0.18 m to 3 m at a resolution of 0.04 m
Detection angle of ∠ = 60° with angle measurement and ∠ = 130°, detection only
Carrier frequency: f = 24.125 GHz (model 204.0/2/3 up to 30.11.12, model 204.9) or f = 25 GHz (model 204.0/2/3 as of 1.12.12)
Method of operation: short pulse process with a 5 GHz bandwidth (model 204.0/2/3 up to 30.11.12, model 204.9) or f = 1.4 GHz bandwidth (model 204.0/2/3 as of 1.12.12)

The bumper radar sensors work according to the Master/Slave principle. The master or slave function can be determined via the connector coding. The master function is determined for the right bumper radar sensor. In other words, the left bumper radar sensor transmits its information via the front end CAN (CAN G) to the right radar bumper sensor, which evaluates the information from both radar sensors passes on the corresponding requests or data via the front end CAN to the control units affected.

To achieve this the bumper radar sensor fulfill the following tasks:

Reading in of sensors, pickups and signals
Evaluation of input factors
Output of signals

Reading in of sensors, pickups and signals

The bumper radar sensors receive the following information via the front end CAN:

Terminal status of terminal 15
Signal "Engine running" or "Drivetrain operational"
Status of function "Blind Spot Assist"
Wheel speeds and wheel rotation direction
Position data for navigation (for the Western European version) (model 204.0/2/3 up to 30.11.12, model 204.9)
Combination switch switch position (S4)
Trailer status (for code (550) Trailer hitch)

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

Evaluation of input factors

The input factors are evaluated by the integrated microprocessors and emission of appropriate signals and requests takes place.

Output of signals

Output of signals takes place via the front end CAN. The right rear bumper radar sensor transmits the following signals via the front end CAN:

Request to issue acoustic warnings
Request to issue system or warning messages

The left bumper radar sensor transmits detection data to the right bumper radar sensor via the front end CAN which uses it to generate the requests to emit a warning.

Blind Spot Assist wiring diagram

PE54.71-P-2100-97FAA