Distronic Distance-Pilot, Function - GF30.30-P-3314FH
Model 238
Up To Model Year 2021
With Code 239 (Adaptive cruise control Pro (DISTRONIC PRO))
Model 238
Up To Model Year 2021
With Code 23P (Drive package)
Function requirements, general
- No undervoltage or overvoltage
- The DISTRONIC Distance-Pilot must be correctly coded
- Engine running or drivetrain operational
- Parking brake not operated
- Gear range "D" engaged (vehicle not in backward movement)
- Vehicle speed 0 to 200 km/h and 200 to 0 km/h
- Vehicle speed 0 to 210 km/h and 210 to 0 km/h (with code 23P (Driving Assistance Package))
- Electronic Stability Program (ESP®) not switched to passive mode
- No active ESP® intervention recognized (vehicle not in sliding movement)
- DISTRONIC Distance-Pilot switched on via the CC lever
- Engine hood closed (with code 23P (Driver Assistance Package Plus))
- Active Parking Assist, no parking may be activated (with code 235 (Parking Pilot with PARKTRONIC) or code P44 (Parking Package))
- Soiling and function test of the DISTRONIC Distance-Pilot controller unit (with code 239 (DISTRONIC Distance-Pilot)) completed successfully
The DISTRONIC Distance-Pilot controller unit performs a soiling and function test to ensure proper operation after each engine start. This assumes an object is in the detection range which can be used as a reference value. If a malfunction is established or there is no object in the detection range of the DISTRONIC Distance-Pilot controller unit, the DISTRONIC Distance-Pilot controller unit cannot be activated.
- Soiling and function test of the short and long range radar sensor (with code 23P (Driver Assistance Package)) completed successfully
Object recognition (e.g. vehicle moving directly ahead) via the radar sensor system is based on the radar measuring procedure. The short and long range radar sensor performs a soiling and function test to secure its perfect function after every engine start. The function test requires an object in the respective detection area which is used as a reference value. If a malfunction is established or if there are no objects in the detection area, the DISTRONIC Distance-Pilot controller unit cannot be activated. When functioning properly, the short and long-range radar transmits the status "radar sensor system operational" to the Mercedes-Benz Intelligent Drive control unit via the suspension FlexRay.
- Standstill control, enable issued (driver door/driver belt buckle and front passenger door closed)
Distronic Distance-Pilot, function
The DISTRONIC Distronic Distance-Pilot regulates the speed and the distance to the vehicle immediately ahead automatically according to the specification of the driver, in that it brakes when necessary and accelerates again, where possible. The distance and speed control takes place by the DISTRONIC Distance-Pilot controller unit (with code 239 (DISTRONIC Distance-Pilot)) or by the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driver Assistance Package Plus)). To do this the DISTRONIC Distance-Pilot controller unit (with code 239 (DISTRONIC Distance-Pilot)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driver Assistance Package Plus)) actively intervenes in the engine management or in the brake system. The handling characteristics of the DISTRONIC Distance-Pilot adapt automatically to the selected transmission mode (DYNAMIC SELECT). In stop and go traffic the DISTRONIC Distance-Pilot brakes vehicle automatically (if necessary through to a standstill). Once the traffic situation again allows this, the DISTRONIC Distance-Pilot accelerates the vehicle automatically up to the set target speed and therefore frees up the driver from these tiring routine tasks (e. g. frequent starting off and braking in stop-and-go traffic.
If the DISTRONIC Distance-Pilot recognizes that strong braking is necessary (e. g. weaving in traffic, a stationary obstacle), the DISTRONIC warning lamp in the instrument cluster lights up and an intermittent alarm tone sounds. Both require the driver to proceed with increased caution and to possibly also brake himself. If the driver reacts to the acoustic warning and brakes, he will be assisted in this by the Brake Assist. This calculates the required brake force amplification according to the situation. A threatening accident can be prevented under certain circumstances or at least one can mitigate its consequences. If the driver fails to respond to the acoustic warning, the Brake Assist initiates (in addition to the visual and acoustic warnings) an automated partial and then maximum full-stop braking.
A reaction to stationary vehicles in the driving lane is possible up to a speed of 60 km/h.
If DISTRONIC Distance-Pilot is switched off, the situation in front of the vehicle continues to be monitored and evaluated. In dangerous situations warnings are given, as described above, or there is autonomous braking.
The following partial functions of the DISTRONIC Distance-Pilot are described in separate documents:
- Cruise control (CC), function
- Automatic speed control
- Variable speed limiter (except code 494 (USA version))
- Permanent limiter
- Steering pilot function (with code 23P (Driving Assistance Package))
Representation of the Assist Graphic in the IC (CLASSIC display)
Operation:
Model 238 Up To Model Year 2019
DISTRONIC Distance-Pilot is operated over the CC lever. The steering column tube module control unit directly reads in the operation signals of the cruise control lever and transmits these via the suspension FlexRay to the Mercedes-Benz Intelligent Drive control unit.
Design of the cruise control lever
If the LED variable speed limiter lights up, the DISTRONIC Distance-Pilot deactivates and the function of the variable speed limiter is programmed. The steering column tube module control unit actuates the variable speed limiter LED directly (except for code 494 (USA version)).
Each time the cruise control lever is actuated, the distance from the preceding vehicle is shown on the instrument cluster for 5 s. Through selection of the operating level "DISTRONIC PLUS" in the menu "Assistance" the distance graphic is shown permanently. Display of the distance graphic can be switched on or off independently of the activity of the automatic distance control. The distance from the preceding vehicle can be adjusted in seven stages between approx. 1.0 and 2.0 s using the DISTRONIC controller.
Model 238 as of model year 2019
The Distance Pilot DISTRONIC is operated using the limiter and Distance Pilot button and the Distance Pilot switch (except code L5C (Multifunction sports steering wheel in nappa leather)) or the limiter and Distance Pilot switch (with code L5C (Multifunction sports steering wheel in nappa leather)) on the steering wheel. The steering wheel electronics directly reads in the control signals and sends them to the Mercedes-Benz Intelligent Drive control unit via the steering wheel CAN, the steering column tube module control unit, and the suspension FlexRay.
Multifunction steering wheel, shown on left-hand drive vehicle except code L5C (Multifunction sports steering wheel in nappa leather)
Multifunction steering wheel, shown on left-hand drive vehicle With Code L5C (Multifunction sports steering wheel in nappa leather)
Each time the limiter and Distance Pilot button, the Distance Pilot switch (except code L5C (Multifunction sports steering wheel in nappa leather)) or the limiter and Distance Pilot switch (with code L5C (Multifunction sports steering wheel in nappa leather)) is pressed, the distance from the preceding vehicle is shown on the instrument cluster for 5 s. Through selection of the operating level "DISTRONIC PLUS" in the menu "Assistance" the distance graphic is shown permanently. Display of the distance graphic can be switched on or off independently of the activity of the automatic distance control. The distance from the preceding vehicle can be adjusted using the Distance Pilot switch (except code L5C (Multifunction sports steering wheel in nappa leather)) or the limiter and Distance Pilot switch (with code L5C (Multifunction sports steering wheel in nappa leather)) in seven stages between approx. 1.0 and 2.0 s.
Display from the DISTRONIC Distance-Pilot in IC, shown on Tacho display Sport
If a vehicle driving immediately ahead is recognized on the lane or on the fast lane, the segments also light up the segments in the speedometer.
Amongst others, the Distance Pilot DISTRONIC controller unit (With Code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (With Code 23P (Driving Assistance Package)) evaluates the following input factors:
- Signal "Engine running" or "Drivetrain operational" (function requirements)
- Status of parking brake (function requirements)
- Engaged gear range (function requirements)
- Driver request using cruise control lever (function requirements) (up to model year 2019)
- Driver request using the limiter and Distance Pilot button, the Distance Pilot switch (except code L5C (Multifunction sports steering wheel in nappa leather)) or the limiter and Distance Pilot switch (with code L5C (Multifunction sports steering wheel in nappa leather)) (function requirements) (as of model year 2019)
- Status of the Active Parking Assist (with code 235 (Parking Pilot with PARKTRONIC) or code P44 (Parking Package)) (function requirements)
- Status of ESP® (function requirements)
- Status of engine hood (with code 23P (Driver Assistance Package))
- Vehicle speed/direction of travel/acceleration
- Object recognition by the DISTRONIC Distance-Pilot controller unit (with code 239 (DISTRONIC Distance-Pilot))
- Object recognition by the short and long range radar sensor (with code 23P (Driver Assistance Package))
- Object recognition by the rear outer bumper radar sensors on the right and left (with code 23P (Driver Assistance Package))
- Object recognition by the Parking System distance sensors (with code 23P (Driver Assistance Package) and code 235 (Parking Pilot with PARKTRONIC))
- Object recognition by the MFK stereo (with code 23P (Driver Assistance Package))
- Recognition of speed limit by the MFK stereo (with code 23P (Driver Assistance Package) and code 513 (Traffic Sign Assist))
- GPS signals (Global Navigation System) /signals for traffic evaluation (with code 23P (Driver Assistance Package)) :
- Engine drive torque
- Brake torque
- Acceleration/yaw rate
- Transmission mode status
- Steering wheel angle
- Driver request to overtake (sets the turn signals on the combination switch)
- Accelerator pedal position
- Brake pedal position
Signal "Engine running" or "Drivetrain operational":
The CDI control unit or the ME-SFI [ME] control unit transmits the signal "Engine running" or "Drivetrain operational" via the drive CAN, the powertrain control unit, and the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Parking brake status:
The Electronic Stability Program control unit transmits the status of the parking brake via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Engaged gear range:
The fully integrated transmission control unit transmits information about the engaged drive range via the drive CAN, the powertrain control unit, and the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Driver request using cruise control lever (Up To Model Year 2019) :
The driver request over the CC lever are directly read in by the steering column tube module control unit. The steering column tube module control unit transmits the operation signals of the cruise control lever via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Driver request using the limiter and Distance Pilot button, the Distance Pilot switch (except code L5C (Multifunction sports steering wheel in nappa leather)) or the limiter and Distance Pilot switch (With Code L5C (Multifunction sports steering wheel in nappa leather)) (function requirements) (as of model year 2019) :
The limiter and Distance Pilot button, the Distance Pilot switch (except code L5C (Multifunction sports steering wheel in nappa leather)), and the limiter and Distance Pilot switch (with code L5C (Multifunction sports steering wheel in nappa leather)) are read in by the steering wheel electronics. The steering wheel electronics transmit the driver requests via the steering wheel CAN, the steering column tube module control unit, and the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Parking Pilot status (With Code 235 (Parking Pilot with PARKTRONIC))
The parking system control unit transmits the status of Active Parking Assist via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
ESP® status:
The Electronic Stability Program control unit transmits the status of the ESP® via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Status of engine hood (With Code 23P (Driver Assistance Package))
The front SAM control unit transmits the status of the hood via the interior CAN, the electronic ignition lock control unit, and the suspension FlexRay to the Mercedes-Benz Intelligent Drive control unit.
Vehicle speed/direction of travel/acceleration:
The vehicle speed is calculated from the wheel speed. The direction of travel is defined by the wheel rotation direction, the acceleration by the increase in the wheel rotation speed. The Electronic Stability Program control unit transmits the wheel speed signals via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Object recognition by the DISTRONIC Distance-Pilot controller unit (With Code 239 (DISTRONIC Distance-Pilot))
The Distance Pilot DISTRONIC controller unit monitors the traffic space in front of the vehicle up to a distance of 200 m.
Object recognition by the short and long range radar sensor (With Code 23P (Driver Assistance Package))
The front short and long range radar sensor monitors the traffic area ahead of the vehicle up to a distance of 200 m.
The front long range radar sensor operates according to the pulse modulated Doppler radar concept, which enables the distances and speeds of individual objects (e. g. vehicles) to be measured independently of each other.
The short and long range radar sensor detects objects in the short and long range area, and transmits corresponding data via the suspension FlexRay to the Mercedes-Benz Intelligent Drive control unit.
Object recognition by the rear outer bumper radar sensors on the left and right (With Code 23P (Driver Assistance Package))
The Mercedes-Benz Intelligent Drive control unit reads in the signals of the left and right rear outer bumper radar sensors via radar CAN 2.
Object recognition by the Parking System distance sensors (With Code 23P (Driver Assistance Package) and code 235 (Parking Pilot with PARKTRONIC))
The parking system control unit reads in the signals of the parking system distance sensors directly, and transmits the object information via the suspension FlexRay to the Mercedes-Benz Intelligent Drive control unit.
Object recognition by the MFK stereo (With Code 23P (Driver Assistance Package))
The stereo multifunction camera consists of two high-resolution mono cameras and an integrated control unit. The laterally offset location of the two mono cameras creates a difference in perspective (parallax displacement) between the left and right optical path. The distance to the object ahead and other variables such as the height thereof are calculated on the basis of the differences between the image data. The MFK stereo detects the objects and tracks. Objects are classified in the types of object and determines their speed and extension. The integrated control unit evaluates image data from the two mono cameras, processes it and sends the corresponding data over the suspension FlexRay to the Mercedes-Benz Intelligent Drive control unit. The Mercedes-Benz Intelligent Drive control unit compares the image data with the signals from the radar sensor system.
Recognition of speed limit by the MFK stereo (With Code 23P (Driver Assistance Package) and code 513 (Traffic Sign Assist))
During vehicle operation, the multifunction camera registers pictures of the traffic signs over or next to the roadway, and transmits the currently detected traffic sign via the suspension FlexRay to the Mercedes-Benz Intelligent Drive control unit and via the suspension FlexRay, the electronic ignition lock control unit, and the user interface CAN to the instrument cluster.
GPS signals/signals for traffic evaluation (With Code 23P (Driver Assistance Package)) :
The head unit evaluates the received GPS data using further information for traffic assessment, and transmits corresponding information via the user interface CAN, the electronic ignition lock control unit, and the suspension FlexRay to the Mercedes-Benz Intelligent Drive control unit.
Engine drive torque:
The CDI control unit or ME-SFI [ME] control unit transmits information about the currently available engine torque via the drive CAN, the powertrain control unit, and the suspension FlexRay to the Electronic Stability Program control unit; this evaluates the information accordingly, and transmits it via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Braking torque:
The Electronic Stability Program control unit transmits information about the currently applied braking torque via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Acceleration/yaw rate:
The acceleration/yaw rate is detected by the acceleration sensor integrated into the Supplemental Restraint System control unit. The Supplemental Restraint System control unit transmits corresponding values via the vehicle dynamics CAN, the Electronic Stability Program control unit, and the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Transmission mode status:
The driver can influence the acceleration behavior of the vehicle through selection of the transmission mode over the AGILITY SELECT switch. The left bottom control panel (for automatic transmissions) or right bottom control panel (for manual transmissions) reads in the status of the DYNAMIC SELECT switch directly and sends the status via the LCP LIN, Audio/COMAND control panel (except code 446 (touchpad only)) or touchpad (with code 446 (touchpad only)), telematics CAN, head unit, user interface CAN, electronic ignition lock control unit, chassis FlexRay, powertrain control unit and drive CAN to the fully integrated transmission control unit. The fully integrated transmission control unit transmits information about the drive program via the drive CAN, the powertrain control unit, and the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Steering wheel angle:
The steering angle is recorded by the steering wheel angle sensor. The steering column tube module control unit reads in the steering wheel angle sensor signals directly, and transmits the information about the steering wheel angle via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Driver request to overtake (sets the turn signals on the combination switch)
The steering column tube module control unit reads in the switch position of the combination switch directly, and transmits it via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Accelerator pedal position:
The powertrain control unit transmits information about the accelerator pedal position via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
Brake pedal position:
The Electronic Stability Program control unit transmits the status of the brake pedal via the suspension FlexRay to the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or to the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)).
The Distance Pilot DISTRONIC controller unit (With Code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (With Code 23P (Driving Assistance Package)) outputs the following initial parameters (requests) :
- Increase/reduce engine torque
- Engage targeted gear (back or upshift)
- Increase/reduce the braking torque
- Emit warning tones, system or warning messages
Raise/reduce engine torque:
The Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) transmits the request "Increase engine torque" or "Reduce engine torque" via the suspension FlexRay to the Electronic Stability Program control unit. The Electronic Stability Program control unit processes this request and further driving dynamics requests and sends them according to their relevance over 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) :
The Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) transmits the request "Engage requested gear" via the suspension FlexRay to the Electronic Stability Program control unit. The Electronic Stability Program control unit processes this request as well as further driving dynamics requests and transmits it according to its relevance via the suspension FlexRay, powertrain control unit and drive train CAN to the fully integrated transmission control unit. This request is however to be understood as a switching recommendation. Downshifting or upshifting of the A/T takes place autonomously itself by the fully integrated transmission control unit, dependent on the current operating condition.
Raise/reduce braking torque:
The Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) transmits the request "Increase braking torque" or "Reduce braking torque" via the suspension FlexRay to the Electronic Stability Program control unit. The Electronic Stability Program control unit reacts by directly actuating the traction system hydraulic unit, which reacts by increasing or decreasing the braking torque according to the brake torque.
Emit warning tones, system or warning messages
The Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) transmits the requests to output warning tones, system or warning messages via the suspension FlexRay, the electronic ignition lock control unit, and the user interface CAN to the instrument cluster, which outputs the corresponding system or warning messages and actuates the instrument cluster speaker directly.
The description of the DISTRONIC Distance-Pilot controller unit takes place, as an example, in the following chronological sequence:
- Activate DISTRONIC Distance-Pilot and drive off automatically
- Automatic distance control
- Lane change (overtaking) (With Code 23P (Driver Assistance Package))
- Convoy driving (With Code 23P (Driver Assistance Package))
- Speed control
- Going back into a lane/person in the front regulation
- Driving around rotaries, through T-intersections and freeway exits (With Code 23P (Driver Assistance Package))
- Automated Stop Vehicle
- Automatic restarting in a traffic jam (With Code 23P (Driver Assistance Package) and code 235 (Park-Pilot with PARKTRONIC))
- Speed Limit-Pilot (With Code 23P (Driver Assist Package) and code 513 (Traffic Sign Assist) and code 531 (COMAND APS))
Activate DISTRONIC Distance-Pilot and drive off automatically
The following options are available for activating DISTRONIC Distance-Pilot:
- Call up the set speed last selected (set speed 20 km/h) with the resume from memory switch on the cruise control lever (up to model year 2019) or the cruise control resume switch on the multifunction steering wheel (as of model year 2019).
The brake pedal must be actuated to activate in standstill.
- To drive off from a standstill, actuate the accelerator pedal shortly or the CC lever shortly (Resume from memory switch)
The vehicle moves off and adapts its speed to the maximum speed of the vehicle immediately ahead up to the selected target speed. If there is no vehicle immediately ahead, the DISTRONIC Distance-Pilot functions like the CC.
For vehicles at a standstill a specified distance limit exists beyond which a stationary vehicle is no longer displayed.
Technical implementation
To do this, the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) receives or transmits the following information or requests:
Input factors:
- Accelerator pedal position
- Driver request using cruise control lever (up to model year 2019)
- Driver request using multifunction steering wheel (as of model year 2019)
- Object recognition
- Vehicle speed/acceleration
- Acceleration/yaw rate
- Brake pedal position
Initial parameters:
- Increase/reduce engine torque
- Increase/reduce the braking torque
- Engage targeted gear (back or upshift)
- Emit warning tones, system or warning messages
Automatic distance control
If the preceding vehicle brakes or accelerates, the Distance Pilot DISTRONIC can introduce the following measures to decelerate or accelerate the vehicle:
- Increase/reduce engine torque
- Increase/reduce the braking torque
The brake application takes place by means of hydraulic pressure controlling in the wheel brake cylinder by the traction system hydraulic unit according to the current vehicle status. To do this the Electronic Stability Program control unit assesses various variables such as the required braking torque.
The driver must press on the brake pedal if he sees that the instigated measures are not adequate to avoid a possible collision.
If the driver does not intervene, an additional intervention by the brake system is made by the Brake Assist.
If the vehicle driving immediately ahead accelerates again, the engine torque is increased and the vehicle also accelerates. The increase in engine torque is dependent on the ascent or the descent involved, among other things.
The maximum (positive) acceleration is dependent on the selected transmission mode. The driver can influence the vehicle's acceleration behavior by selecting the transmission mode using the transmission mode button.
The driver furthermore has the option of operating the accelerator pedal to accelerate the vehicle (e. g. when overtaking). As soon as the driver actuates the accelerator pedal, no distance control occurs. The IC shows the "DISTRONIC passive" message. If the automatic distance control requires a higher acceleration than the driver prescribes, the driver request is overlaid by the request for automatic distance control and the "DISTRONIC passive" message goes off.
Technical implementation
To do this, the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) receives or transmits the following information or requests:
Input factors:
- Object recognition
- Vehicle speed/acceleration
- Acceleration/yaw rate
- Engine drive torque
- Accelerator pedal position
- Driver request using cruise control lever (up to model year 2019)
- Driver request using multifunction steering wheel (as of model year 2019)
- Brake pedal position
Initial parameters:
- Increase/reduce engine torque
- Increase/reduce the braking torque
- Engage targeted gear (back or upshift)
- Emit warning tones, system or warning messages
Lane change (overtaking) (With Code 23P (Driver Assistance Package))
During an overtaking maneuver at a speed over 70 km/h, the vehicle is also accelerated automatically. To do this the driver must initiate the overtaking maneuver by setting the turn signal. If the automatic distance control is activated, the Mercedes-Benz Intelligent Drive control unit recognizes the intention of the driver to overtake and accelerates the vehicle while taking account of the distance to the vehicle driving ahead.
When approaching a slowly moving vehicle and therefore an active automatic intervention by the brake system, this is then canceled insofar as the driver initiates the overtaking procedure by operating the turn signal. If required, the vehicle is additionally accelerated.
If there is no vehicle in the detection range of the radar sensor system after the overtaking procedure, the automatic distance control changes over to automatic speed control. If a vehicle driving immediately ahead is subsequently detected as a target object after the overtaking procedure the automatic speed control function changes over again into the automatic distance control function.
The overtaking maneuver is broken off in the following situations:
- Risk of collision with the current target object
- Risk of collision with a vehicle moving directly at the side and ahead
Technical implementation
To do this, the Mercedes-Benz Intelligent Drive control unit receives or transmits the following information or requests:
Input factors:
- Object recognition
- Driver request over the combination switch
- Vehicle speed/acceleration
- Acceleration/yaw rate
- Engine drive torque
- Accelerator pedal position
Initial parameters:
- Increase/reduce engine torque
- Increase/reduce the braking torque
- Engage targeted gear (back or upshift)
- Emit warning tones, system or warning messages
Convoy driving (With Code 23P (Driver Assistance Package))
The convoy driving function is only available in selected Western European countries with corresponding legislation (overtaking on the right prohibited at speeds in excess of 80 km/h as well as limitation of the overtaking speed to a maximum of 20 km/h relative to the convoy). If a convoy forms in the left-hand lane due to the current traffic situation that could theoretically be overtaken in the right-hand lane, this is detected by DISTRONIC Distance-Pilot controller unit. A convoy overtaking maneuver on the right-hand lane (overtaking speed over 20 km/h relative to the convoy, maximum overtaking speed 85 km/h) is only introduced if the following prerequisites are met:
- Convoy speed below 80 km/h
- Well built, multi-lane road with a maximum permissible speed of over 80 km/h
The DISTRONIC Distance-Pilot in combination with the NAVs prevents a possibly illegal overtaking on the right in right-hand traffic or overtaking on the left in left-hand traffic on a freeway or federal highways like a freeway (Freeway-Pilot). To do this the distance to the vehicle to the left lane (right-hand traffic) or to the right lane (left-hand traffic) is moderately regulated in that the system measures the distance to vehicles on the left lane or to the right for left-hand traffic. If the system prevents overtaking the convoy, this can be ended by short actuation of the accelerator pedal by the driver.
Technical implementation
To do this, the Mercedes-Benz Intelligent Drive control unit receives or transmits the following information or requests:
Input factors:
- Object recognition
- Vehicle speed
- Accelerator pedal position
- Engine drive torque
- GPS signals/signals for traffic assessment
Initial parameters:
- Increase/reduce engine torque
- Increase/reduce the braking torque
- Engage targeted gear (back or upshift)
- Emit warning tones, system or warning messages
Speed control
If the vehicle is in active distance control and the preceding vehicle accelerates to over 210 km/h or leaves the radar sensor system detection range, distance control switches to speed control.
Technical implementation
To do this, the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) receives or transmits the following information or requests:
Input factors:
- Object recognition
- Driver request using cruise control lever (up to model year 2019)
- Driver request using multifunction steering wheel (as of model year 2019)
- Vehicle speed/acceleration
- Acceleration/yaw rate
- Engine drive torque
- Accelerator pedal position
- Brake pedal position
Initial parameters:
- Increase/reduce engine torque
- Engage targeted gear (back or upshift)
- Increase/reduce the braking torque
Going back into a lane/person in the front regulation
If the vehicle driving immediately ahead turns off and there is another vehicle in front, the system only switches over to the new target vehicle if it is moving. The system does not operate for stationary objects unless a preceding vehicle is tracked to a standstill. If while driving a vehicle turns in front within the safe distance to the vehicle driving immediately ahead, the distance to this new vehicle is regulated. If the vehicle is in speed control and a vehicle turns onto the lane driven in this vehicle is registered as the vehicle driving immediately ahead. If the distance to the swinging-in vehicle lies below the value that was preselected, Distance Pilot DISTRONIC decelerates the vehicle. If the requested brake power is not sufficient, a visual and acoustic warning is issued, and the driver has to press the brake pedal. If the driver fails to respond, the Brake Assist initiates (in addition to the visual and acoustic warnings) an automated partial and then maximum full-stop braking.
The negative acceleration (deceleration) is limited to 50 % (approx. 5.0 m/s2
) of the maximum possible braking power.
The DISTRONIC Distance-Pilot will be deactivated in the process. This process is indicated to the driver through the output of an intermittent warning tone via the instrument cluster speaker and a warning on the instrument cluster. The driver can activate the DISTRONIC Distance-Pilot controller unit again.
Technical implementation
To do this, the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) receives or transmits the following information or requests:
Input factors:
- Object recognition
- Vehicle speed
- Brake pedal position
Initial parameters:
- Increase/reduce engine torque
- Increase/reduce the braking torque
- Engage targeted gear (back or upshift)
- Object information
- Emit warning tones, system or warning messages
Driving around rotaries, through T-intersections and freeway exits (With Code 23P (Driver Assistance Package))
If the vehicle driving immediately ahead leaves the detection area of the radar sensor system in one of the above-mentioned traffic situations, then the current speed is maintained:
- Approx. 10 s before a traffic circle or a T-intersection
- Approx. 12 s prior to a freeway exit and approx. 4 s after a freeway exit
If, after this, no new vehicle is detected driving immediately ahead, the vehicle accelerates or decelerates to the established set speed.
Since traffic situations are subject to alteration, the digital map data has to be regularly updated.
Technical implementation
To do this, the Mercedes-Benz Intelligent Drive control unit receives or transmits the following information or requests:
Input factors:
- GPS signals/signals for traffic assessment
- Vehicle speed
- Brake pedal position
Initial parameters:
- Increase/reduce engine torque
- Increase/reduce the braking torque
- Engage targeted gear (back or upshift)
Automated Stop Vehicle
For an activated DISTRONIC Distance-Pilot, the vehicle will follow the vehicle driving in front to a standstill. The deceleration here is due to the service brake. The service brake also secures a stationary vehicle against rolling away.
After a defined time period the electric parking brake is also activated (standstill control safety strategy).
Securing the vehicle using the DISTRONIC Distance-Pilot (standstill control) does not replace securing the vehicle for parking.
Technical implementation
To do this, the Distance Pilot DISTRONIC controller unit (with code 239 (Distance Pilot DISTRONIC)) or the Mercedes-Benz Intelligent Drive control unit (with code 23P (Driving Assistance Package)) receives or transmits the following information or requests:
Input factors:
- Object recognition
- Vehicle speed
- Brake pedal position
Initial parameters:
- Increase/reduce engine torque
- Engage targeted gear (back or upshift)
- Increase/reduce the braking torque
Automatic restarting in a traffic jam (With Code 23P (Driver Assistance Package) and code 235 (Park-Pilot with PARKTRONIC))
This function is available on freeways or Federal highways similar to a freeway for starting off again. If the vehicle with an active DISTRONIC Distance-Pilot comes to a standstill, the vehicle will follow the target vehicle for up to 30 s without driver interaction. The driving off area is also monitored by ultrasonic sensors and the driver is also informed about the readiness to drive off condition of the vehicle by a display. If during the start off process violation of the gap in front of the vehicle is recognized, a take over warning occurs and reduction of the acceleration and the driver is warned optically and acoustically. If a warning is issued, the driver must take action himself (accelerator pedal/brake pedal). If a warning occurs, continuation of driving must be acknowledged by the driver.
Model 238
up to model year 2021
with code 23P (Drive package)
with code 513 (Road sign recognition system)
Automatic driving off again is deactivated at intersections with Stop signs.
Technical implementation
To do this, the Mercedes-Benz Intelligent Drive control unit receives or transmits the following information or requests:
Input factors:
- Object recognition
- Vehicle speed
- Brake pedal position
Initial parameters:
- Increase/reduce engine torque
- Engage targeted gear (back or upshift)
- Increase/reduce the braking torque
Additional function requirements for Speed Limit Pilot (With Code 23P (Driver Assist Package Plus) and code 513 (Traffic Sign Assist))
- Speed-Pilot switched on over the head unit
Speed Limit-Pilot (With Code 23P (Driver Assist Package) and code 513 (Traffic Sign Assist) and code 531 (COMAND APS))
If the displayed speed limit changes for an active DISTRONIC Distance-Pilot, the set speed changes automatically. This occurs unless the set speed was already changed in a foresighted manner by the driver. If the DISTRONIC Distance-Pilot was passivated through actuation of the accelerator pedal, the speed limit is adopted which is greater than the set speed.
The change in the displayed speed limit always takes place at the height of the traffic sign. For an entrance lane to a built-up area (towns/cities), adaptation of the set speed occurs in a foresighted manner so that the adaptation of the set speed still occurs before the beginning of the built-up area. In doing so the displayed speed limit only changes due to the traffic sign assistants for multiple trips in built-up area. Irrespective of the Distance Pilot DISTRONIC control status, the displayed speed limit is set as the set speed on pulling the cruise control lever (up to model year 2019) or using the cruise control resume switch (as of model year 2019) if the Speed Limit Pilot is configured in the head unit. If no speed limit is displayed for actuation of the lever, resumption of the previously set speed occurs.
Technical implementation
To do this, the Mercedes-Benz Intelligent Drive control unit receives or transmits the following information or requests:
Input factors:
- Recognized traffic signs
- Vehicle speed
- Brake pedal position
Initial parameters:
- Increase/reduce engine torque
- Engage targeted gear (back or upshift)
- Increase/reduce the braking torque
The following traffic situations show the limits of the DISTRONIC Distance-Pilot:
Obstacles and stationary vehicles
The DISTRONIC Distance-Pilot does not brake for obstacles or stationary vehicles which were not previously registered as the target object. If, for example, the detected vehicle turns off and there is an obstacle or stationary vehicles behind it, no automatic intervention by the brake system occurs.
Curves, curved entrances and exits
The DISTRONIC Distance-Pilot can only provides limited detection of vehicles in curves. One's own vehicle can then brake unexpectedly or late.
Vehicles moving across in front of one's own vehicle
The DISTRONIC Distance-Pilot may detect vehicles in cross traffic by mistake. For an activated distance control the vehicle can start off unintended, (e. g. at a traffic light with cross-traffic).
Offset driving style
The DISTRONIC Distance-Pilot may not be able to detect vehicles driving offset to one side. The distance to the vehicle in front becomes too small.
Lane change by other vehicles
The DISTRONIC Distance-Pilot does not yet detect the vehicle moving into the lane. The distance to the vehicle moving into the lane becomes too small.
Narrow vehicles
The DISTRONIC Distance-Pilot does not detect the vehicle in front at the edge of the carriageway because of its narrow width. The distance to the vehicle in front becomes too small.
| Electrical function schematic for DISTRONIC Distance-Pilot | Model 238 up to model year 2021 with code 239 (Adaptive cruise control Pro (DISTRONIC PRO)) except code 23P (Drive package) | PE30.30-P-2068-97DCA | |
| Model 238 up to model year 2019 with code 23P (Drive package) | PE30.30-P-2068-97DCB | ||
| Model 238 as of model year 2019 up to model year 2021 with code 23P (Drive package) | PE30.30-P-2068-97DCC | ||
| Overview of system components for driver assistance systems | GF54.00-P-9998FH |