Cruise Control (CC), Function - GF30.30-P-0001RFM
Model 205
as of model year 2019
with code 239 (Active Distance Assist DISTRONIC)
Model 205
as of model year 2019
with code 23P (Driving Assistance package)
Model 205
as of model year 2019
with code 440 (Cruise control)
Model 253 (except 253.99)
as of model year 2020
with code 239 (Active Distance Assist DISTRONIC)
Model 253 (except 253.99)
as of model year 2020
with code 23P (Driving Assistance package)
Model 253 (except 253.99)
as of model year 2020
with code 440 (Cruise control)
Model 253.99
with code 239 (Active Distance Assist DISTRONIC)
Function requirements, general
- Engine running or drivetrain operational
- Gear range "D" engaged (transmission 722, 724, 725)
- Vehicle speed:
- Vehicle speed v ≥ 20 to 250 km/h (except code 239 (Active Distance Assist DISTRONIC) and except code 23P (Driving Assistance Package)) or when distance control is deactivated (with code 239 (Active Distance Assist DISTRONIC) or code 23P (Driving Assistance Package))
- Vehicle speed v ≥ 20 to 200 km/h (with code 239 (Active Distance Assist DISTRONIC) and distance control activated)
- Vehicle speed v ≥ 20 to 210 km/h (with code 23P (Driving Assistance Package) and distance control activated)
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.
The functionally relevant requests are transmitted via the suspension FlexRay to the Electronic Stability Program control unit by the Distance Pilot DISTRONIC control unit in vehicles with code 239 (Active Distance Assist DISTRONIC) or by the Mercedes-Benz Intelligent Drive control unit in vehicles with code 23P (Driving Assistance Package). The Electronic Stability Program control unit processes these and prioritizes them according to the parameters it has evaluated.
Cruise control buttons on multifunction steering wheel, shown on sports variant, 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 pressure point alters the specified speed by v = 1 km/h. If the switch is pressed beyond the pressure point then the specified speed alters by v = 10 km/h each time. If the switch is held at or beyond the pressure 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 (transmission 722, 724, 725) (function requirements)
- Vehicle speed
- Driver request via cruise control switch and cruise control resume switch
- Accelerator pedal position
Operating condition for engine/drivetrain:
The CDI control unit or the ME-SFI [ME] control unit transmits the signal "Engine running" or "Drivetrain operational" via the drive CAN, powertrain control unit and suspension FlexRay to the Electronic Stability Program control unit and also to the Distance Pilot DISTRONIC controller unit (with code 239 (Active Distance Assist DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
For model 253.99, the powertrain control unit transmits the "Drivetrain operational" signal via the suspension FlexRay to the Electronic Stability Program control unit and also to the Distance Pilot DISTRONIC controller unit (with code 239 (Active Distance Assist DISTRONIC)).
The CDI control unit or the ME-SFI [ME] control unit or the powertrain control unit coordinates, among other things, all acceleration, deceleration or gearshift requests. 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 (transmission 722, 724, 725):
The fully integrated transmission 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 (Active Distance Assist DISTRONIC) also to the Distance Pilot DISTRONIC controller unit or for vehicles with code 23P (Driving Assistance Package) to the Mercedes-Benz Intelligent Drive control unit.
Vehicle speed:
The vehicle speed is calculated by the Electronic Stability Program control unit from the wheel speeds.
For vehicles with code 239 (Active Distance Assist DISTRONIC), the Electronic Stability Program control unit also transmits the wheel speed signals via suspension FlexRay to the DISTRONIC Distance-Pilot controller 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 233 (DISTRONIC PLUS) also to the Distance Pilot DISTRONIC controller 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 (Active Distance Assist DISTRONIC) also to the Distance Pilot DISTRONIC controller unit or for vehicles with code 23P (Driving Assistance Package) to the Mercedes-Benz Intelligent Drive control unit.
For model 253.99, the powertrain control unit transmits information on the accelerator pedal position via the suspension FlexRay to the Electronic Stability Program control unit and also to the Distance Pilot DISTRONIC controller unit (with code 239 (Active Distance Assist DISTRONIC)).
The following initial parameters (requests) are issued to implement the function:
- Increase/reduce the drive torque
- Engage targeted gear (downshift or upshift) (transmission 722, 724, 725)
- Increase/reduce the braking torque
Increase/reduce the drive torque:
For vehicles without code 239 (Active Distance Assist DISTRONIC) and without 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 "Increase/reduce drive torque" request via the suspension FlexRay, powertrain control unit and engine CAN to the CDI control unit (diesel engine) or the ME-SFI [ME] control unit (gasoline engine) or via the suspension FlexRay to the powertrain control unit (model 253.99).
The "Increase/reduce drive torque" request is transmitted via the suspension FlexRay to the Electronic Stability Program control unit for vehicles with code 239 (Active Distance Assist DISTRONIC) by the Distance Pilot DISTRONIC controller 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 sends it according to its priority to the CDI control unit (diesel engine) or the ME-SFI [ME] control unit (gasoline engine) via the suspension FlexRay, powertrain control unit and engine CAN.
The CDI control unit or the ME-SFI [ME] control unit or the powertrain control unit accordingly implements this request.
Engage targeted gear (downshift or upshift) (transmission 722, 724, 725):
For vehicles without code 239 (Active Distance Assist DISTRONIC) and without code 23P (Driving Assistance Package), the Electronic Stability Program control unit evaluates the input factors and other 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 unit.
The "Engage requested gear" request is transmitted via the suspension FlexRay to the Electronic Stability Program control unit for vehicles with code 239 (Active Distance Assist DISTRONIC) by the Distance Pilot DISTRONIC controller 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 suspension FlexRay, powertrain control unit and drive CAN to the fully integrated transmission control unit.
This request is to be understood as a shift recommendation.
Downshifting or upshifting of the automatic transmission takes place autonomously by the fully integrated transmission control unit dependent on the current operating condition.
Raise/reduce braking torque:
For vehicles without code 239 (Active Distance Assist DISTRONIC) and without code 23P (Driving Assistance Package), 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 (Active Distance Assist DISTRONIC) by the Distance Pilot DISTRONIC controller 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.
Hybrid vehicle or model 253.99
For model the kinetic energy is converted within defined limits into electrical energy (regenerative braking). If the required braking torque exceeds the deceleration through regenerative braking, the regenerative braking system control unit also actuates Electronic Stability Program control unit and the traction system hydraulic unit and therefore the service brake.
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 via cruise control resume switch (except code 494 (USA version))
- 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.
For vehicles without code 239 (Active Distance Assist DISTRONIC) and without code 23P (Driving Assistance Package), the Electronic Stability Program control unit transmits the set speed (specified speed) via suspension 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 (Active Distance Assist DISTRONIC) by the Distance Pilot DISTRONIC controller unit or for vehicles with code 23P (Driving Assistance Package) by the Mercedes-Benz Intelligent Drive control unit.
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
- Speed v < 25 km/h
- Gear range is not "D" (transmission 722, 724, 725)
The following activities are started in order to reach or maintain the set speed:
- Increase/reduce the drive torque
- Engage targeted gear (downshift or upshift) (transmission 722, 724, 725)
- 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 limiter selected via the limiter switch and Distance Pilot (S163/1s16) (with code L5C (Multifunction sports steering wheel in nappa leather) or via the limiter button and Distance Pilot (S163/1s15) (except code L5C (Multifunction sports steering wheel in nappa leather)
Function sequence for variable limiter (except code 494 (USA version))
The variable 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) (transmission 722, 724, 725)
- 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 actuation > 90 % and driven vehicle speed v < 20 km/h below the set maximum speed) (transmission 722, 724, 725)
- ESP switched to passive mode
Function sequence for permanent limiter
The maximum speed of the vehicle can be limited in increments 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 code 446 (Touchpad only), the navigation takes place with the Audio/COMAND control panel. The Audio/COMAND control panel sends the corresponding control signals (except code 446 (Touchpad only)) to the head unit via the telematics CAN.
- With code 446 (Touchpad only) or code 448 (Touchpad), the navigation takes place with the Touchpad. The touchpad (with code 446 (Touchpad only)) or code 448 (Touchpad)) transmits the respective control signals via the telematics CAN to the head unit.
- The navigation can occur with code 531 (COMAND APS) per 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 on the upper control panel control unit via the vehicle button. In vehicles with code 446 (Touchpad only), the upper control panel control unit sends the status of the Vehicle button to the head unit via LCP-LIN, the touchpad and the telematics CAN. In vehicles without code 446 (Touchpad only), the upper control panel control unit sends the status of the Vehicle button to the head unit via LCP-LIN, the Audio/COMAND control panel and the telematics CAN.
For vehicles without code 239 (Active Distance Assist DISTRONIC) and without code 23P (Driving Assistance Package), the head unit transmits the set maximum speed via the user interface CAN, electronic ignition lock control unit and suspension FlexRay to the Electronic Stability Program control unit.
For vehicles with code 239 (Active Distance Assist DISTRONIC), the head unit transmits the set maximum speed via the user interface CAN, electronic ignition lock control unit and suspension 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 on 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
| Electrical function schematic for cruise control (CC) | PE30.30-P-2051-97FBC | ||
| PE30.30-P-2051-97FBD | |||
| Overview of system components for driver assistance systems | GF54.00-P-9998RFM |