Component description for DISTRONIC electric controller unit - GF30.30-P-3213RF

MODEL 205, 253 with CODE 239 (DISTRONIC PLUS) 

Show on model 205 

Location 

The DISTRONIC controller unit is located in the middle of the radiator.

Task 

The DISTRONIC controller unit assesses the traffic situation ahead of the vehicle through evaluation of the data from the integral long range radar. The detected data serve to implement the following functions:

• Cruise control
• Variable SPEEDTRONIC (except code 494 (USA version))
• Permanent limiter
• DISTRONIC PLUS
• Distance warning
• Adaptive brake assistant

The DISTRONIC controller unit compares the permanent target and actual values with each other and evaluates the respective driver requirements. In order to implement the automatic distance and speed control the DISTRONIC controller unit sends the respective requests for acceleration, deceleration and switching over the chassis FlexRay (Flex E) after evaluation of all input factors.

This means that the front DISTRONIC controller unit has the following tasks:

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

Reading in input factors 

The DISTRONIC controller unit receives the following input signals via the suspension FlexRay:

• Operating condition for engine/drivetrain
• Engaged gear range/stage
• Parking brake status
• Engine drive torque
• Brake torque
• Acceleration/yaw rate
• Driver request through the cruise control lever (S40/4)
• Driver request to overtake through setting the turn signal
• Vehicle speed/acceleration
• Steering wheel angle
• Brake pedal position
• Accelerator pedal position

The resulting functions are described in the respective function descriptions (see also 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 

Amongst other things the DISTRONIC controller unit sends the following initial parameters over the suspension FlexRay:

• System status of DISTRONIC PLUS
• Object information
• Request to increase/reduce engine torque
• Request to increase/limit stage
• Request to increase/reduce braking torque
• Request to emit warning tones, system or warning messages
• Requests to introduce PRE-SAFE® measures (with CODE 299 (PRE-SAFE® system))

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

Body 

The DTR controller unit contains the following components:

• Long range radar
• Control unit

Properties of the long range radar:

• Detection ranges:
  • s < 30 m for a detection angle of = 30°
  • s = 30 up to 100 m at a detection angle of = 20°
  • s = 100 up to 200 m for a detection angle of = 12°
• Carrier frequency: 77 GHz (in accordance with the "Pulse Doppler Principle" for independent measurement of distance and speed)

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