Component description for radar sensors control unit - GF30.30-P-3301FLM

MODEL 212 as of model year 2014 with CODE 23P (Driving Assistance package Plus) 

Shown on left-hand drive vehicle 

Fig 1: Radar Sensors Control Unit - Model 212

Courtesy of MERCEDES-BENZ USA

Location 

For left-hand drive vehicles at the front in the front passenger footwell the radar sensors control unit is located on the control units carrier plate.

For right-hand drive vehicles the radar sensors control unit is located on the right A-pillar at the rear of the cover for the A-pillar.

Task 

The radar sensors control unit is the evaluation and arithmetic unit for the short range and long range radar along with the object and lane data of the stereo multifunction camera (A40/13). This in turn means that the radar sensors control unit is responsible for the following tasks:

• Reading in of sensors and signals 
• Evaluation of input factors 
• Controlling functions 
• Output of signals 

Reading in of sensors and signals 

The input factors are received via the following connections:

• Suspension FlexRay (Flex E) 
• Radar CAN 1 (CAN S1) 
• Radar CAN 2 (CAN S2) 

Chassis FlexRay 

The radar sensors control unit receives the following information over the chassis FlexRay:

• Long range radar data
• Diagnostic data from long range radar
• Status of the accelerator pedal
• Gear range status
• Stage status
• Service brake, status
• Yaw rate status
• Status information from the driver assist or driving safety system
• Wheel speeds and wheel rotation direction
• Braking torque
• Drive torque
• Tire pressure monitor (with code 475 (Tire pressure monitor (Premium)), Schrader)
• Parking brake status
• Status of steering angle
• Position data from navigation (for the Western Europe version)
• Driver request through the cruise control lever (S40/4)
• Driver request via menu settings in the instrument cluster (A1)
• Turn signal status (with code 237 (Active Blind Spot Assist))
• Driving lane data (with code 238 (Active Lane Keeping Assist))

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

Radar CAN 1 

The signals for the following components are received over the radar CAN 1:

• Left front bumper DISTRONIC (DTR) sensor (B29/2)
• Right front bumper DISTRONIC (DTR) sensor (B29/3)

Radar CAN 2 

The signals for the following components are received over the radar CAN 2:

• Left rear bumper radar sensor (B29/6)
• Right rear bumper radar sensor (B29/7)
• Center rear bumper radar sensor (B29/10)

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 the relevant components are then actuated.

Controlling functions 

The radar sensors control unit actuates the following functions to match the particular equipment involved:

• Variable Speed Limiter function (Speedtronic) (except code 494 (USA version))
• Permanent Speed Limiter (winter tires)
• DISTRONIC PLUS (with CODE 233 (DISTRONIC PLUS))
• DISTRONIC PLUS with Steer Assist (with CODE 266 (Steer Assist))
• BAS PLUS (with code 268 (BAS PLUS))
• BAS PLUS with intersection assist (with code 269 (BRAKE ASSIST PLUS CROSSING TRAFFIC (BAS+Q)))
• PRE-SAFE® brake (with code (300) Collision reduction (CMS)))
• Rear-end PRE-SAFE® (with CODE 253 (Rear collision warning and protection system))
• Pedestrian protection emergency brake function (with code 271 (Autonomous intervention by the brake system/pedestrian protection))
• Active Blind Spot Assist (with CODE 237 (Active Blind Spot Assist))
• Active Lane Keeping Assist (with CODE 238 (Active Lane Keeping Assist))

Output of signals 

The signals are issued over the following connections:

• Chassis FlexRay 
• Radar CAN 1 
• Radar CAN 2 

Chassis FlexRay 

With code 233 (DISTRONIC PLUS) the radar sensors control unit transmits the following signals via the suspension FlexRay:

• Increase engine torque
• Reduce engine torque
• Gear restriction
• Stage increase
• Stage reduction
• Warning tone output
• System and warning indicators output
• Request for PRE-SAFE® measures
• Radar requirements of the long range radar (vehicle / operation-specific data
• Diagnosis request

With code 237 (ACTIVE BLIND SPOT ASSIST), the radar sensors control unit sends the following signals via the chassis FlexRay:

• Wheel selective intervention by the brake system
• Activation of left blind spot assist ready and warning indicator (M21/1e2) or right blind spot assist ready and warning indicator (M21/2e2)
• Warning tone output
• System and warning indicators output
• Radar requirements of the long range radar (vehicle / operation-specific data)
• Diagnosis request

With code 238 (ACTIVE BLIND SPOT ASSIST), the radar sensors control unit sends the following signals via the chassis FlexRay:

• Wheel selective intervention by the brake system
• Warning tone output
• System and warning indicators output
• Radar requirements of the long range radar (vehicle / operation-specific data)
• Diagnosis request

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

Radar CAN 1 

The radar sensors control unit transmits the following signals via the radar CAN 1:

• Radar requirements of the short range radar (vehicle / operation-specific data)
• Diagnosis request

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

Radar CAN 2 

The radar sensors control unit transmits the following signals via the radar CAN 2:

• Radar requirements of the short range radar (vehicle / operation-specific data)
• Diagnosis request

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