Component description for intelligent radar sensor control unit - GF30.30-P-3305CE

WARNING: This page is about a different car, the 2011 Mercedes-Benz C350, 2010 Mercedes-Benz C350, 2009 Mercedes-Benz C350, and 2008 Mercedes-Benz C350. However, it is still accessible from the selected car via links, so may be relevant.

MODEL 204.0/2 with CODE (234) Blind Spot Assist as of model year 2012/YoM 11 facelift

MODEL 204.3 with CODE (234) Blind Spot Assist

Shown on a disassembled bumper (internal view)

Fig 1: Identifying Intelligent Radar Sensor Control Unit Components Location

Courtesy of MERCEDES-BENZ USA

Location

The left rear radar sensor is mounted on the left inner side of the rear bumper, while the right rear radar sensor is mounted on the right inner side of the rear bumper.

Task

The rear bumper radar sensors detect vehicles in the blind spot over the integrated vehicles radar sensor system. The integral radar sensors are ultra wideband radar sensors with the following properties:

Radar sensor detection range s = 0.18 to 3 m, at a resolution of s = 0.04 m
Acquisition angle ∠ = 60° with angle determination and ∠ = 130° only detection (track)
Radar sensor with f = 24.125 GHz carrier frequency
Method of operation: short pulse method with f = 5 GHz band width

The rear bumper radar sensors operate according to the "master-slave" principle. The "master" or "slave" function can be established over the plug coding.

The "master function" is defined for the right rear bumper radar sensor. In other words, the left radar sensor sends its requests to output warning and readiness messages via the front end CAN (CAN G) to the right rear bumper radar sensor which evaluates information from both rear bumper radar sensors and forwards corresponding requests via the front end CAN to the respective control units.

The rear bumper radar sensors also 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 input factors are read in over the chassis CAN (CAN E) and contain the following information:

Status of the function "Blind Spot Assist" (from the IC (A1)
Position data from navigation (for the Western Europe version)
Status of the gear range
Wheel speeds and wheel rotation direction
Trailer status (for code (550) Trailer hitch)

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

Evaluation of input factors

The input factors are evaluated by the integrated microprocessors and the relevant components are then actuated.

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:

'Warning buzzer' request (A1h1)
Request for the multifunction display (A1p13)
Request to the left Blind Spot Assist readiness and warning indicator (M21/1e2) and the right Blind Spot Assist readiness and warning indicator (M21/2e2)

The left rear bumper radar sensor transmits detection data to the right 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