GF30.30-P-3200RI Distronic, Function
GF30.30-P-3200RI DISTRONIC, Function
- with CODE (219) Distronic (DTR)
- refinement package
- as of model year 09
Detection of a vehicle traveling ahead with DISTRONIC activated
DISTRONIC function requirements in general
^ "Circuit 61 ON" (engine running)
^ "ADTR" coded in Central Gateway control unit (N93)
^ ESP not deactivated
^ Parking brake not applied
^ Selector lever in position "D"
^ The CC [TPM] push button switch (S40/4) must be pressed to switch over to the DISTRONIC position (LIM indicator lamp off) (except code (494) USA version)
^ Dirt and function test of the DTR radar sensor (A89b1) completed successfully
^ Brake pedal not actuated
^ Speed of the vehicle >30 km/h
DISTRONIC in general
DISTRONIC regulates the speed and the distance to the vehicle driving ahead according to the driver's specifications (target speed and required distance) in the range of 30 to 180 km/h.
In doing so, DISTRONIC regulates the set target speed in an empty lane (no vehicle moving ahead) as per conventional cruise control. As the car approaches a preceding vehicle, the speed is reduced in order to maintain the target distance set by the driver by:
- Reducing the engine output
- Activating the brakes
- Shifting the gear
If the traffic situation allows an increase in speed as the vehicle immediately ahead has accelerated or left the lane, for example, Distronic increases the speed back up to the set target speed.
The DTR control unit (A89n1) actuates the radar sensor, evaluates the radar sensor data and then transmits this data via the engine compartment CAN (CAN C) to the ESP, SPS [PML] and BAS control unit (N47-5).
Following evaluation of all sensor data and input signals, the ESP control unit takes over control of the entire longitudinal movement of the vehicle in DISTRONIC operation. For this purpose, it sends signals (for shifting gear, accelerating or decelerating) via the engine compartment CAN to the corresponding control units. The ESP control unit also actuates warning tones and displays in the instrument cluster (A1).
DISTRONIC function sequence
The function sequence is described in the following points:
^ Dirt and function test
^ Automatic acceleration
^ Automatic braking
^ Target speed
^ DISTRONIC activation
^ Target distance
^ Special driving situations
^ DISTRONIC deactivation
Dirt and function test
The DTR control unit performs a dirt and function test of the radar sensor to ensure smooth functioning of the radar system after each engine start. If a malfunction is established or if there are no objects (for the function test) in the radar sensor detection range, DISTRONIC cannot be activated and the message "DISTRONIC Unavailable" appears in the left multifunction display (A1p13) of the instrument cluster.
DISTRONIC is not available when, for example, the radar plate in the radiator grille is dirty or iced up, operation is not possible due to weathering or the transmitting and receiving signals are restricted by external influences (e.g. EMC interference).
Automatic acceleration
The automatic maximum acceleration by DISTRONIC is limited to around 1 m/s2 for reasons of safety and comfort.
Automatic braking
Intervention by the brake system is restricted to 20 % (approx. 2 m/s2 ) of the maximum possible deceleration capacity for reasons of safety and comfort. Driving situations that require more than 20 % braking power are signaled by the driver optically by the red light of the warning lamp and the DTR indicator lamp (A1e59) in the instrument cluster and acoustically by an intermittent warning tone. This intermittent warning tone signals the driver to observe the traffic situation and to intervene if necessary, or reassume full control of the vehicle.
The intermittent warning tone is turned off automatically when the situation becomes less critical and cannot be deactivated manually.
Target speed
The minimum target speed that can be set is 30 km/h and the maximum target speed 180 km/h.
The target speed can be increased or decreased in 1 km/h or in 10 km/h increments (two settings) by moving the CC [TPM] push button switch (S40/4 or S40 for code (494) USA version) up or down.
DISTRONIC activation
DISTRONIC can be activated from 30 km/h up to a speed of 180 km/h.
By moving the CC [TPM] switch up or down, DISTRONIC is activated with the current vehicle speed as the target speed.
By pulling the CC [TPM] switch, DISTRONIC is activated with the last saved target speed provided that a target speed has already been saved since the last engine start (set). If no target speed is stored, the current vehicle speed is set as the target speed.
Component Identification:
If the accelerator pedal is not completely released after activating DISTRONIC, the left multifunction display shows the warning "DTR Passive".
If DISTRONIC is activated, the message "DTR" and the set target speed appear for a few seconds in the left multifunction display. Then the DISTRONIC distance graphic is displayed.
If a vehicle is detected in the front, the warning lamp and white DTR indicator lamp are lit.
Component Identification:
The vehicle ahead is shown with the actual distance in meters.
If no other vehicle is detected in front of the vehicle, DISTRONIC functions like the conventional cruise control.
Target distance
The target distance to the vehicle driving ahead can be set in six increments between approximately 1.0 s and 2.0 s depending on the speed of the vehicle using the DTR distance potentiometer (N72r1)
At setting three and at a speed of 100 km/h, this corresponds to a target distance of around 42 m. The target distance is converted from seconds to meters depending on the speed of the vehicle and is displayed in the form of a line in the left multifunction display of the instrument cluster. The target distance in the distance indicator matches the current vehicle speed without the driver having to adjust the DTR distance potentiometer.
The legally required minimum distance is thus always guaranteed in the setting range for the target distance.
If the set target speed to the vehicle ahead falls short, DISTRONIC reduces the speed.
In driving situations requiring more than 20 % braking power, the DTR warning and indicator lamp in the instrument cluster are lit and the intermittent warning tone signals the driver to watch the traffic situation so that he can intervene by measured heavy braking or by steering if necessary.
Component Identification:
Special driving situations
- If the driver accelerates the vehicle independently higher than the acceleration set by DISTRONIC or accelerates up to over 180 km/h, DISTRONIC is not deactivated, but switches to passive. The message "DISTRONIC Passive" appears in the left multifunction display of the instrument cluster and distance control to the vehicle ahead does not take place for this acceleration procedure. When the driver releases the accelerator pedal again (vehicle speed drops), DISTRONIC resets to the set target speed and distance control is once again activated.
- No regulation takes place relative to stationary objects.
- If a vehicle cuts in between the host vehicle and the vehicle ahead (target vehicle), the system switches over to the new target vehicle.
- If, during the journey, the vehicle ahead pulls out of the lane and another vehicle is now moving ahead of the host vehicle, then the system will only control the distance to this new vehicle if it is moving. In case of any obstacle in the way, the DTR warning and indicator lamp and the intermittent warning tone signal any impending collision.
DISTRONIC deactivation
DISTRONIC is deactivated when:
- The CC [TPM] switch is pushed forwards
- The brake pedal is operated.
- The CC [TPM] push button switch is pressed in the Variable Speed Limiter position to switch over (LIM indicator lamp is lit) (except code (494) USA version)
- Selector lever is set to "N"
- Vehicle moving at a speed of <30 km/h is "lost"
- Function of the radar is no longer given
