GF30.30-P-3200GQ Distronic, Function

GF30.30-P-3200GQ DISTRONIC, Function
- with CODE (219) Distronic (DTR)
- as of model year 09

Component Identification:

DISTRONIC function requirements in general
^ "Circuit 61 ON" (engine running)
^ "ADTR" (Advanced Distronic) coded in the central gateway control unit (N93)
^ Soiling and function test of the DTR radar sensor (A89b1) completed successfully
^ Electronic Stability Program (ESP) not deactivated
^ No ESP control intervention function
^ Parking brake not applied
^ Gear range "D" engaged
^ Brake pedal not actuated
^ Vehicle speed >30 km/h (up to CY 09 model refinement package)
^ CC [TPM] push button (S40 or S40/4) in the position DISTRONIC (LIM indicator lamp (LIMITER) off) (except code (494) USA version)

DISTRONIC in general
DISTRONIC regulates the specified speed and specified distance of the vehicle ahead, based on driver commands in a range of 30 to 180 km/h (up to CY 09 model refinement package) or from 0 to 200 km/h (as of CY 09 model refinement package).

To do this, Distronic sets the driver's specified speed as a conventional cruise control, when the traffic lane is empty (no vehicles ahead). As the car approaches a preceding vehicle, the speed is reduced in order to maintain the target distance set by the driver by:
- Reducing engine power
- Activating the brakes
- Changing gear (downshift)

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.
In curves adaptation of the speed takes place on comfort grounds dependent on a maximum permissible lateral acceleration in the curve. If the target destination gets lost in the curve, the speed is held until cornering ends or the target destination is recognized again.

The signals from the CC push button are detected by the steering column tube module (N80) and sent over the engine compartment CAN (CAN C) to the ESP control unit (N47-5).

The set maximum speed is transmitted to the instrument cluster (A1) from the ESP control unit over the engine compartment CAN. The ESP control unit also actuates warning chimes and displays in the instrument cluster.

The DTR control unit (A89) actuates the DTR radar sensor (A89b1), evaluates the sensor data from the DTR radar sensor and transfers the data over the dynamics CAN (CAN H) to the ESP control unit.
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 acceleration, deceleration and switching to the respective control units via the engine compartment CAN signals.

The acceleration/deceleration requests (to intervene in the engine control) are sent by the ESP control unit via the engine compartment CAN to the CDI control unit (N3/9) (for diesel engines) or ME-SFI [ME] control unit (N3/10) (for gasoline engines).

Shift requests to the automatic transmission are transmitted by the ESP control unit over the engine compartment CAN to the electric controller unit (VGS) (Y3/8).

DISTRONIC function sequence
The function sequence is described in the following points:
^ Soiling and function test function sequence
^ Automatic acceleration function sequence
^ Automatic braking function sequence
^ Distronic activation function sequence
^ Specified speed function sequence
^ Function sequence for specified distance
^ Special driving situations function sequence
^ Function sequence for stopping vehicle behind the target vehicle (as of CY 09/model refinement package)
^ Function sequence for Distronic deactivation

Soiling and function test function sequence
The DTR controller unit performs a soiling and function test of the radar sensor to ensure smooth functioning of the radar system after each engine start. The DISTRONIC cannot be activated if a malfunction is established or if there are no objects (for the function test) in the detection range of the radar sensor.

The message "DISTRONIC currently unavailable" appears in the multifunction display (A1p13) from the instrument cluster.

Automatic acceleration function sequence
The automatic maximum acceleration of the DISTRONIC is limited on safety and comfort grounds to about 1 m/s 2 (up to CY 09/ model refinement package) or about 2.5 m/s 2 (as of CY 09/model refinement package).

Automatic braking function sequence
Intervention by the brake system is limited to 20 % (approx. 2 m/s 2 ) (up to CY 09 model refinement package) or to 40 % (approx. 4 m/s 2)
(as of CY 09 model refinement package) of the maximum possible deceleration output for safety and comfort reasons. Driving situations which require more than 20% (up to CY 09/model refinement package) or 40% (as of CY 09/model refinement package) braking power are signaled to the driver optically by means of lighting up of the DTR indicator lamp (A1e59) in the instrument cluster and acoustically by means of an interval warning tone. This interval warning tone requires the driver to observe the traffic situation and to intervene himself (to take over control) if necessary.
The intermittent warning tone is turned off automatically when the situation becomes less critical and cannot be deactivated manually.

Distronic activation function sequence
DISTRONIC can be activated at a speed of 30 to 180 km/h (up to CY 09 model refinement package) or from >0 to 260 km/h (as of CY 09 model refinement package). However, at speeds < 30 km/h, it can only be activated if a preceding vehicle is detected.

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. By moving the CC [TPM] switch up or down, DISTRONIC is activated with the current vehicle speed as the target speed.

If no vehicle immediately ahead is recognized for the activated DISTRONIC one or two segments are lit up in the area of the set specified speed in the speedometer.

If there is a vehicle recognized immediately ahead for the activated DISTRONIC the segments between the measured speed of the vehicle ahead and the set specified speed is lit up in the electronic speedometer (A1p8). The vehicle immediately ahead is shown in the multifunction display of the instrument cluster with the current distance from it in meters.

The message "Distronic unavailable" is displayed if:
- The radar plate in the radiator grille is dirty or iced up
- Radar operation is not possible due to weather conditions
- Transmission/reception signals are limited by external factors (e.g. electromagnetic interference)
- Radar system is outside the operating temperature
- The DTR radar sensor has not detected an object ahead for a longer period of time (e.g. vehicles or traffic signs)

A warning tone is also sounded in addition to the message.

Component Identification:

Specified speed function sequence
The minimum adjustable target speed is 30 km/h and the maximum is 180 km/h (up to CY 09/model refinement package) or 200 km/h (as from CY 09/model refinement package).
The CC [TPM] switch can be moved up or down to different degrees to increase or reduce the specified speed in 1 km/h or 10 km/h increments (two settings).
If DISTRONIC PLUS is activated (from CY 09/model refinement package) at a speed <30 km/h, the target speed is automatically set to 30 km/h. If DISTRONIC (as of CY 09/model refinement package) is activated at a speed between > 200 km/h and 260 km/h, the target speed is automatically set to the maximum permissible target speed of 200 km/h.

Function sequence for specified distance
With the DTR distance potentiometer (S40r1 or S40/4r1), the specified distance from the vehicle in front can be set in six steps between about 1.0 and 2.0 s, to match vehicle speed. At setting three this corresponds to a target distance of approx. 42 m at a speed of 100 km/h.

The specified distance is converted from seconds to meters (depending on the driver's own vehicle speed), and displayed in the form of a white line in the 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 that require more than 20% (up to CY 09/ model refinement package) or 40% (as of CY 09/model refinement package) braking power (hazardous situations), the DTR indicator lamp is lit red on the instrument cluster and an intermittent warning tone warns the driver to watch the traffic situation and take the appropriate action by braking strongly or by steering as required.

Component Identification:

Special driving situations function sequence
- If the driver accelerates the vehicle independently higher than the acceleration set by DISTRONIC or accelerates up to over 180 km/h (up to CY 09/model refinement package) or 200 km/h (as from CY 09/model refinement package), DISTRONIC is not deactivated, but simply switches to passive. The multifunction display on the instrument cluster displays the message "Distronic passive" and no distance control from the vehicle in front is performed during this acceleration. 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.
- The system does not operate for stationary objects (e.g. vehicles) unless a preceding vehicle is tracked to a standstill (as of CY 09/model refinement package).
- 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 the preceding vehicle turns off and there is another vehicle in front, the system only switches over to the new target vehicle if it is moving. In the event that a stationary obstruction is encountered, the DTR warning lamp and the intermittent acoustic warning warn the driver about an impending collision.
- If the preceding vehicle leaves the same lane at a speed <30 km/h (as of CY 09/model refinement package), is DISTRONIC is deactivated and a deactivation tone sounds.

Function sequence for stopping vehicle behind the target vehicle (as of CY 09/model refinement package)
In a situation where the target vehicle stops, regulation continues up to a standstill and is then switched off. The driver is informed through fading out of the segment ring in the speedometer and a subsequently sounding signal tone through the DISTRONIC switching off. The set braking torque at the point in time of switching off is slowly reduced after the switching off tone.

The DISTRONIC is already deactivated in the following situations before reaching a standstill:
- Loss of the target vehicle at <25 km/h
- On gradients >4 % the DISTRONIC is deactivated at a higher speed to match the gradient (e.g. 4 % gradient at 7 km/h or 30 % gradient at 25 km/h)

Function sequence for Distronic deactivation
DISTRONIC is deactivated when:
- The CC [TPM] switch is pushed forwards
- The CC [TPM] push button switch is pressed in the Variable Speed Limiter position to switch over (LIM indicator lamp lights up) (except code (494) USA version)
- The brake pedal is operated.
- Parking brake is actuated
- Gear range "N" or "R" engaged
- ESP operates
- ESP switched off
- ESP deactivated (a fault)
- The preceding vehicle is no longer registered (lost) at a speed of <30 km/h (up to CY 09/model refinement package) or <25 km/h (as of CY 09/model refinement package)
- Radar function no longer available
- Ignition is switched off (circuit 15 OFF)