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Function: No vehicle in front, cruise control > < Function - Sound settings

A5

  • Vehicle electrics
  • System description - adaptive cruise control
  • Self diagnosis, V.A.G Inspection Service
  • Function: Vehicle in front

Description
Description
   
t  The driver of the blue vehicle activates the control and sets the desired speed „V“ and desired distance „a“ via the cruise control system switch -E45-. This switch position is scanned by the steering column electronics control unit -J527- and transmitted across the CAN bus to the adaptive cruise control unit -J428-. The adaptive cruise control unit -J428- scans the current speed, which is placed on the running gear CAN by the control unit in dash panel insert -J285-, and transmits a specified acceleration to the engine control unit -J623- so that the specified speed can be reached. The vehicle accelerates up to the specified speed.
  A48-10172
t  A vehicle (shown in red) ahead in the same lane is detected by the adaptive cruise control unit -J428-, which responds by modifying the specified acceleration and transmitting the new value to the engine control unit -J623- so that the specified distance can be maintained. The engine control unit -J623- decides whether, in order to achieve the specified acceleration, it is necessary to reduce the fuel injection quantity or apply the brake (the latter is performed via the ABS control unit -J104-). As a result, the speed „V“ of the blue vehicle is reduced such that the desired distance „a“ is attained.
  A48-10173
t  A second vehicle (motorbike) cuts in between the vehicles. The specified acceleration calculated by the adaptive cruise control unit -J428- cannot be realised by the engine control unit -J623-. In other words, the system cannot maintain the desired distance on its own by applying the brakes, and there is a risk of a collision with the motorbike. An optical warning (in the control unit in dash panel insert -J285-) and an acoustic warning (over the loudspeakers) prompt the driver to apply the brakes in order to avoid a collision.
  A48-10174
t  The ACC is deactivated when the driver applies the brakes. The driver can now either reactivate the settings which were active prior to the brake application using the »resume« function (by pulling the cruise control system switch -E45-), or set a new speed and distance (by pressing the SET button). The motorbike in front moves out of the lane. This is detected by the radar sensor. The blue vehicle accelerates up to the specified speed again.
  A48-10175

  • Vehicle electrics
  • System description - adaptive cruise control
  • Self diagnosis, V.A.G Inspection Service
  • Function: Vehicle in front

Function: No vehicle in front, cruise control > < Function - Sound settings