Cruise Control (CC), Function - GF30.30-P-0001FR
Model 257, 290
up to model year 2021
Shown on models 257, 2
The functionally relevant requests are transmitted via the suspension FlexRay to the Electronic Stability Program control unit for vehicles with code 239 (Distance Pilot DISTRONIC) by the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) by the Mercedes-Benz Intelligent Drive control unit. The Electronic Stability Program control unit processes these and prioritizes them according to the respective own evaluated parameters. The DISTRONIC Distance-Pilot controller unit is heated by a radiation dome heater which is directly actuated by the controller unit.
Function requirements, general
- Engine running or drivetrain operational
- Gear range "D" engaged (transmission 725)
- Vehicle speed:
- Vehicle speed v ≥ 30 to 250 km/h or maximum speed (except code 239 (Distance Pilot DISTRONIC) and except code 23P (Driver Assistance Package)) or for a deactivated distance control (with code 239 (Distance Pilot DISTRONIC) or code 23P (Driver Assistance Package))
- Vehicle speed v ≥ 30 to 200 km/h (with code 239 (Distance Pilot DISTRONIC))
- Vehicle speed v ≥ 30 to 210 km/h (with code 23P (Driver Assistance Package) and activated distance control)
Cruise control - general
The cruise control regulates the vehicle speed constantly and automatically to the desired speed set by the driver To do this the cruise control evaluates the driver's commands and the current driving condition
Cruise control buttons on multifunction steering wheel, shown on model 257 except code L5C (Multifunction sports steering wheel in nappa leather), left-hand drive vehicle
The cruise control is activated with the stored specified speed using the cruise control resume switch (top switch position). If the cruise control is already activated, the current speed limit will be adopted as the new specified speed. The cruise control is switched off by pushing the cruise control resume switch downwards.
The specified speed can be altered in steps of v = 1 km/h or v = 10 km/h using the cruise control switch.
Actuation up to the actuation point increases the set speed by v = 1 km/h. If the switch is pressed beyond the actuation point then the specified speed increases each time by v = 10 km/h. If the switch is held at or beyond the actuation point, the specified speed is changed every t = 0.6 s.
The following input factors are evaluated to implement the function:
- Operating condition of engine/drivetrain (function requirements)
- Engaged gear range (function requirements)
- Vehicle speed
- Driver request via cruise control switch and cruise control resume switch
- Accelerator pedal position
Vehicle speed:
The vehicle speed is calculated by the Electronic Stability Program control unit from the wheel speeds.
For vehicles with code 239 (DISTRONIC PLUS), the Electronic Stability Program control unit also transmits the wheel speed signals via chassis FlexRay to the DISTRONIC Distance-Pilot controller unit.
Operating condition for engine/drivetrain:
The CDI control unit or the ME-SFI [ME] control unit transmits the "Engine running" signal or "Drivetrain operational" signal via the drive CAN, powertrain control unit and suspension FlexRay to the Electronic Stability Program control unit and for vehicles with code 239 (Distance Pilot DISTRONIC) also to the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) to the Mercedes-Benz Intelligent Drive control unit.
The CDI control unit or the ME-SFI [ME] control unit, amongst other things, coordinates acceleration, deceleration or switching requirements. In doing so it prioritizes requests according to their relevance, while taking account of the additional variables such as the charge level of the high voltage on-board electrical system, the operating status of the ancillaries or requests from comfort systems such as the automatic climate control.
Engaged gear range:
The fully integrated transmission control electric controller unit control unit transmits information on the engaged drive range via the drive CAN, powertrain control unit and suspension FlexRay to the Electronic Stability Program control unit and for vehicles with code 239 (Distance Pilot DISTRONIC) also to the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) to the Mercedes-Benz Intelligent Drive control unit.
For vehicles with code 23P (Driving Assistance Package), the Electronic Stability Program control unit additionally transmits the wheel speed signals to the Mercedes-Benz Intelligent Drive control unit via the suspension FlexRay.
Driver request via cruise control switch and cruise control resume switch:
The cruise control switch and the cruise control resume switch transmit the driver's requests via the steering wheel electronics, steering wheel CAN, steering column tube module control unit and via the suspension FlexRay to the Electronic Stability Program control unit and for vehicles with code 239 (Distance Pilot DISTRONIC) also to the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) to the Mercedes-Benz Intelligent Drive control unit.
Accelerator pedal position:
The powertrain control unit transmits information on the accelerator pedal position via the suspension FlexRay to the Electronic Stability Program control unit and for vehicles with code 239 (Distance Pilot DISTRONIC) also to the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) to the Mercedes-Benz Intelligent Drive control unit.
The following initial parameters (requests) are issued to implement the function:
- Increase/reduce the drive torque
- Engage targeted gear (back or upshift)
- Increase/reduce the braking torque
Increase/reduce the drive torque:
For vehicles without code 239 (DISTRONIC PLUS) and without code 23P (Driving Assist Package Plus), the Electronic Stability Program control unit evaluates the input factors and other driving dynamic requests and transmits the "Increase/reduce drive torque" request via chassis FlexRay, powertrain control unit and engine CAN to the CDI control unit or the ME-SFI [ME] control unit.
The "Increase/reduce drive torque" request is transmitted via the suspension FlexRay to the Electronic Stability Program control unit for vehicles with code 239 (Distance Pilot DISTRONIC) by the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) by the Mercedes-Benz Intelligent Drive control unit. The Electronic Stability Program control unit processes this and transmits it according to its priority via the chassis FlexRay, powertrain control unit and engine CAN to the CDI control unit or the ME-SFI [ME] control unit.
The CDI control unit or the ME-SFI [ME] control unit implements this request.
Engage targeted gear (downshift or upshift):
For vehicles without code 239 (Distance Pilot DISTRONIC) and except code 23P (Driving Assistance Package), the Electronic Stability Program control unit evaluates the input factors as well as additional driving dynamic requests and transmits the "Engage requested gear" request via the suspension FlexRay, powertrain control unit and drive CAN to the fully integrated transmission control electric controller unit control unit.
The "Engage requested gear" request is transmitted via the suspension FlexRay to the Electronic Stability Program control unit for vehicles with code 239 (Distance Pilot DISTRONIC) by the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) by the Mercedes-Benz Intelligent Drive control unit. The Electronic Stability Program control unit evaluates this and transmits this according to its priority via the suspension FlexRay, powertrain control unit and drive CAN to the fully integrated transmission control electric controller unit control unit.
This request is to be understood as a shift recommendation.
The downshifting or upshifting of the automatic transmission is realized independently by the fully integrated transmission control electric controller unit control unit depending on the current operating status.
Raise/reduce braking torque:
For vehicles without code 239 (DISTRONIC Distance-Pilot) and without code 23P (Driving Assist Package Plus), the Electronic Stability Program control unit evaluates the input factors and actuates the traction system hydraulic unit accordingly.
The "Increase/reduce braking torque" request is transmitted via the suspension FlexRay to the Electronic Stability Program control unit for vehicles with code 239 (Distance Pilot DISTRONIC) by the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) by the Mercedes-Benz Intelligent Drive control unit. The Electronic Stability Program control unit evaluates these and actuates the traction system hydraulic unit appropriately.
The traction system hydraulic unit reacts by increasing or reducing the braking torque.
Cruise control encompasses the following subfunctions:
- Function sequence for automatic speed control
- Function sequence, variable speed limiter
Additional automatic speed control function requirements
- Cruise control selected using variable speed limiter switch (without code 494 (USA version)) (variable speed limiter LED off)
- Electronic Stability Program (ESP®) not switched to passive mode
Function sequence for automatic speed control
Through actuation of the cruise control resume switch, the last stored specified speed is applied, provided a specified speed has been stored since the last engine start. If no set speed was stored, the current vehicle speed is set as the set speed. The target speed is displayed in the IC.
The driver also has the option to accelerate beyond the set target speed through actuation of the accelerator pedal (for example when overtaking). The set speed is regulated again after removal of the acceleration request (releasing the accelerator pedal).
The following events deactivate the automatic speed control:
- Push the cruise control resume switch downwards
- Switchover to the variable speed limiter
- Depressing the brake pedal
- Active regulation of the ESP® or ESP® switched off
For vehicles without code 239 (DISTRONIC Distance-Pilot) and without code 23P (Driving Assist Package Plus), the Electronic Stability Program control unit transmits the set speed (target speed) via chassis FlexRay, electronic ignition lock control unit and user interface CAN to the instrument cluster.
The set speed (specified speed) is transmitted via the suspension FlexRay, electronic ignition lock control unit and user interface CAN to the instrument cluster for vehicles with code 239 (Distance Pilot DISTRONIC) by the Distance Pilot DISTRONIC control unit or for vehicles with code 23P (Driving Assistance Package) by the Mercedes-Benz Intelligent Drive control unit.
- Speed v < 25 km/h
- Gear range is not "D" (transmission 725)
The following activities are started in order to reach or maintain the set speed:
- Increase/reduce the drive torque
- Engage targeted gear (back or upshift)
- Increase/reduce the braking torque
Function sequence, variable speed limiter
The DTCO has the following subfunctions:
- Function sequence for variable speed limiter (except code 494 (USA version))
- Function sequence for permanent limiter
Additional function sequence for variable speed limiter (except code 494 (USA version))
- Variable speed limiter selected over variable speed limiter switch (variable speed limiter LED lights up):
The steering column tube module control unit actuates the variable speed limiter LED directly.
Function sequence for variable speed limiter (except code 494 (USA version))
The variable speed limiter can be used to limit the vehicle's maximum speed to a freely selectable value (e.g. v = 50 km/h in urban traffic). The driver can accelerate the vehicle up to the set limit.
If the set limit was reached, the following activities are started:
- Reduce drive torque
- Engage targeted gear (shift down)
- Raise braking torque
If the driver switches to the variable limiter on the steering wheel, the automatic speed control is deactivated.
The following events deactivate the variable speed limiter:
- Push the cruise control resume switch downwards
- Changeover to CC
- Kickdown (accelerator pedal pressed by > 90 % and vehicle speed v < 20 km/h below selected maximum speed) (for transmission 725)
- ESP switched to passive mode
Function sequence for permanent limiter
The maximum speed of the vehicle can be limited in steps of v = 10 km/h from v = 160 to 240 km/h. Adjustment of the permissible maximum speed takes place in the menu "Settings", "Vehicle" and "Limitation (winter tires)" in the head unit. For navigation in the operating menu the following options are available:
- Except with code 446 (Touchpad only) it is possible to navigate with the audio/COMAND control panel. The Audio/COMAND control panel sends the respective control signals via the telematics CAN to the head unit.
- With code 446 (Touchpad only) or code 448 (Touchpad), the navigation takes place with the Touchpad. The touchpad sends the relevant operation signals to the head unit via the telematics CAN.
- The navigation can occur over voice control. The driver FSE microphone is directly read in by the head unit.
- The navigation can occur over the head unit finger navigation pad and the "Back" button on the steering wheel. The head unit finger navigation pad and the "Back" button transmit the relevant control signals via the steering wheel electronics, the steering wheel CAN, the steering column tube module control unit, the suspension FlexRay, the electronic ignition lock control unit and the user interface CAN to the head unit.
- The operating menu can be called up over vehicle button the upper control panel control unit (with code 246 (Analog clock)). The status of the Vehicle button is transmitted by the upper control panel control unit via the LCP-LIN, the Audio/COMAND control panel (except code 446 (Touchpad only)) or the touchpad (with code 446 (Touchpad only)) and the telematics CAN to the head unit.
For vehicles without code 239 (DISTRONIC Distance-Pilot) and without code 23P (Driving Assist Package Plus), the head unit transmits the set maximum speed via the user interface CAN, electronic ignition lock control unit and chassis FlexRay to the Electronic Stability Program control unit.
For vehicles with code 239 (DISTRONIC Distance-Pilot), the head unit transmits the set maximum speed via user interface CAN, electronic ignition lock control unit and chassis FlexRay to the DISTRONIC Distance-Pilot controller unit.
For vehicles with code 23P (Driving Assistance Package), the head unit sends the set maximum speed via the user interface CAN, electronic ignition lock control unit, and the suspension FlexRay to the Mercedes-Benz Intelligent Drive control unit.
Approximately v = 10 km/h before reaching the set maximum speed a message appears in the instrument cluster multifunction display that indicates a maximum speed limitation. The driver can accelerate the vehicle up to the set maximum speed. The head unit transmits the set maximum speed via the user interface CAN, electronic ignition lock control unit and user interface CAN to the IC.
If the maximum speed was reached the following activities are started:
- Reduce drive torque
- Engage targeted gear (shift down)
- Raise braking torque
The permanent limiter also remains active for a switched off variable speed limiter.
| Electrical function schematic for cruise control (CC) Model 257 up to model year 2021 with code 239 (Adaptive cruise control Pro (DISTRONIC PRO)) | Model 257 up to model year 2021 with code 23P (Drive package) Model 257 up to model year 2021 with code P20 (Driving assistant package Plus) | PE30.30-P-2051-97XBB | |
| Model 257 up to model year 2021 except code 239 (Adaptive cruise control Pro (DISTRONIC PRO)) except code 23P (Drive package) except code P20 (Driving assistant package Plus) | PE30.30-P-2051-97XBA | ||
| Overview of system components for driver assistance systems | GF54.00-P-9998FR |