Distance Control, Basic Function - GF30.30-P-9903A
MODEL all (CAR)
with CODE 239 (Active Distance Assist DISTRONIC)
with CODE 23P (Driving Assistance package)
with CODE P20 (Driving Assistance package Plus)
Overview
This service information contains the following information:
- General
- Function requirements
- Distance control
General
Distance control regulates the distance from a preceding vehicle as specified by the driver. The system uses the information of the radar sensor system and camera for this purpose. The distance control can react to swinging in vehicles, vehicles in front and stationary vehicles. On approaching a preceding vehicle, the distance control system reduces the speed and brakes the vehicle, to a standstill if necessary.
The driver is visually and acoustically warned if the system detects that a stronger brake application is required (e.g. vehicles swinging in, stationary obstacle). Both require the driver to proceed with increased caution and to possibly also brake himself. If the driver reacts to the warning and brakes, he/she is supported in this by the Active Brake Assist. If a collision is likely, Active Brake Assist intervenes to prevent an accident if possible. As soon as the traffic situation permits again, the vehicle accelerates up to the specified speed set in the speed control system.
If the driver actuates the accelerator pedal, distance control is switched to passive until the driver releases the accelerator pedal again.
If the fast lane is free and a lane change is indicated by flashing, the vehicle accelerates rapidly to the speed control system's specified speed.
The distance control system's driving style is influenced by the selected drive program. In the "Sport" drive program, for example, acceleration is more dynamic and sharp. In the "Comfort" drive program, distance control operates with greater emphasis on comfort. In the drive program "MaxRange", the distance control works in a fuel consumption optimized manner with max. range and recuperation (vehicles with electric motor).
Distance control is operated with the buttons on the steering wheel. The traffic situation is still evaluated even when distance control is switched off. As described above, warnings are then output or braking takes place in dangerous situations.
Function requirements
- Driver's door closed and driver present
- Passenger door CLOSED
- Engine running or drivetrain operational
- Parking brake released
- Gear range "D" engaged (vehicle not in backward movement)
- Distance control system switched on
- Vehicle speed 0 to 200 km/h; for vehicles with Driving Assistance Package, up to 210 km/h
- Speed setting 20 to 200 km/h; on vehicles with Driving Assistance Package, up to 210 km/h
Distance control
Distance control is activated when the radar sensor detects a preceding vehicle and the driver sets a specified distance from it.
Distance control evaluates the driving and traffic situation on the basis of the following parameters:
- Vehicle speed/acceleration
- Location information (position finding) (vehicles with Driving Assistance Package, country-dependent)
- Information for traffic assessment
- Accelerator pedal position
- Engine drive torque
- Brake pedal position
- Brake torque
- Acceleration/yaw torque
- Transmission mode
- Steering movements
- The driver request "Overtake":
- ESP® status
- Engine hood status
Starting off
Distance control is activated by pressing the accelerator pedal or by selecting a set speed.
If a vehicle is located in the radar sensor's detection range, one's own vehicle follows it. Otherwise, the system activates speed control.
In stop-and-go traffic, the vehicle automatically drives off again within 3 s or 30 s of stopping and follows the vehicle in front. When the vehicle is stationary for longer, distance control switches off.
Vehicles with Driving Assistance Package and Active Parking Assist
On vehicles with Active Parking Assist, the traffic area ahead of the vehicle is additionally monitored by the distance sensors.
On roads with separate lanes (e.g. freeway), the vehicle automatically drives off again within 30 s of stopping and follows the vehicle in front.
Maintaining distance
During vehicle operation, distance control can only be activated if a vehicle is located in the radar sensor detection range. This vehicle is then followed at the set distance.
The driver can continue to accelerate the vehicle himself. Distance control is interrupted as long as he actuates the accelerator pedal. A text message indicates this status.
If the distance control system requests higher acceleration than that specified by the driver, the driver's specification is overridden. Distance control switches to speed control under the following conditions:
- The preceding vehicle leaves the radar sensor detection range.
- The preceding vehicle accelerates to over 200 km/h or 210 km/h (vehicles with Driving Assistance Package).
Convoy driving (Western European countries with corresponding legislation) (vehicles with Driving Assistance Package)
If a convoy forms as a result of the traffic situation on the left-hand lane, it may be overtaken on the right under the following prerequisites:
- Convoy speed below 80 km/h
- Overtaking speed less than 20 km/h relative to the convoy
- Maximum overtaking speed 85 km/h
- Well built, multi-lane road with a maximum permissible speed of over 80 km/h
The preceding vehicle is followed at the set distance.
Pulling out/pulling in
If the prec+eding vehicle pulls out during distance control and is ahead of a further vehicle, the distance is regulated to the new vehicle.
If a vehicle pulls into the safe distance from the preceding vehicle, the distance is regulated to this new vehicle. If a vehicle pulls onto the lane on which the own vehicle is driving during speed control, the distance is regulated to this vehicle.
If necessary, the distance control system brakes the own vehicle. This deceleration is limited to a maximum of 50 % of the possible braking power. The distance control is deactivated in this connection (up to Driving Assistance Package generation 5). This process is signaled to the driver via the output of warnings (up to Driving Assistance Package generation 5).
Distance control can then be activated again.
Driving through traffic circles, T-intersections, and freeway exits (vehicles with Driving Assistance Package, depending on country)
Before entering traffic circles, T-intersections, and freeway exits, distance control brakes the vehicle.
If the preceding vehicle leaves the radar sensor detection range in one of the listed situations, the current speed is maintained:
- 10 s before a traffic circle or a T-intersection
- 12 s before a freeway exit
- 4 s after a freeway exit
If no preceding vehicle is then detected, the vehicle accelerates or decelerates to the set speed.
As road courses are subject to changes, regularly updating the digital map material is necessary.
Overtaking (vehicles with Driving Assistance Package with deactivated lane change assist)
When overtaking at a speed over 70 km/h, distance control accelerates the vehicle automatically. The driver must introduce the overtaking process by flashing. System-related, automatic brake application is suspended (evasion). If required, the vehicle is accelerated more extensively.
The overtaking maneuver is broken off in the following situations:
- Risk of collision with the vehicle in front
- Risk of collision with a vehicle driving ahead at the side
Stop vehicle
When distance control is active, the vehicle follows the preceding vehicle to a standstill. The vehicle is decelerated. The service brake secures the stationary vehicle against rolling away.
After a short time, the electric parking brake is activated (standstill control securing strategy). Securing the vehicle does not replace securing the vehicle when parking.
Active Stop-and-Go Assist (vehicles with Driving Assistance Package, as of market launch model 167)
In stop-and-go traffic on freeways, the distance control also takes over the task of lane guidance up to approx. 60 km/h. The vehicle automatically drives off again after a stop within 1 min and orients itself based on the vehicle in front and the lane markings.
For a display with green steering wheel, the active Stop-and-Go Assist is switched on.
Function schematics
| Function schematic for detection of transmission position | Model 118, 177, 247, 293 with code 239 (Active Distance Assist DISTRONIC) Model 118, 177, 247, 293 with code 23P (Driving Assistance package) Model 167 with code 23P (Driving Assistance package) Model 167 with code P20 (Driving Assistance package Plus) | PE27.19-P-2500-97A | |
| Regulate distance, function schematic | Model 118, 177, 247, 293 with code 239 (Active Distance Assist DISTRONIC) except code 23P (Driving Assistance package) Model 167 with code 239 (Active Distance Assist DISTRONIC) except code 23P (Driving Assistance package) except code P20 (Driving Assistance package Plus) | PE30.30-P-2502-97A | |
| Model 118, 167, 177, 247, 293 with code 23P (Driving Assistance package) Model 167 with code P20 (Driving Assistance package Plus) | PE30.30-P-2502-97B | ||
| Subsystems | |||
| Functional limitations of distance control, detailed information | GF30.30-P-0024-01A | ||
| Increase speed, basic function | GF30.30-P-1000A | ||
| Reduce speed, basic function | GF30.30-P-1001A | ||
| Environment monitoring, basic function | Model all (CAR) with code 235 (Active Parking Assist with PARKTRONIC) with code 23P (Driving Assistance package) Model all (CAR) with code 235 (Active Parking Assist with PARKTRONIC) with code P20 (Driving Assistance package Plus) |
GF54.65-P-1000A | |
| Collision warning system, basic function | GF54.70-P-9900A | ||
| Traffic area monitoring, basic function | GF54.71-P-1000A | ||
| Track guidance, basic function | Model all (CAR) with code 23P (Driving Assistance package) Model all (CAR) with code P20 (Driving Assistance package Plus) |
GF54.71-P-9900A | |
| Steering torque specification, basic function | Model all (CAR) with code 23P (Driving Assistance package) Model all (CAR) with code P20 (Driving Assistance package Plus) |
GF54.71-P-9903A | |
| Additional basic functions | |||
| Brakes, basic function | GF42.00-P-9900A | ||
| Control units | |||
| Intelligent driving control unit, basic function | Model all (CAR) with code 23P (Driving Assistance package) Model all (CAR) with code P20 (Driving Assistance package Plus) |
GF30.30-P-9890A | |
| Distance control controller unit, basic function | Model all (CAR) with code 239 (Active Distance Assist DISTRONIC) |
GF30.30-P-9891A | |
| Parking system control unit, basic function | Model all (CAR) with code 235 (Active Parking Assist with PARKTRONIC) with code 23P (Driving Assistance package) Model all (CAR) with code 235 (Active Parking Assist with PARKTRONIC) with code P20 (Driving Assistance package Plus) |
GF54.65-P-9890A | |
| Components | |||
| Intelligent driving radar sensor, basic function | Model all (CAR) with code 23P (Driving Assistance package) Model all (CAR) with code P20 (Driving Assistance package Plus) |
GF54.71-P-2005A |