DISTRONIC PLUS, function - GF30.30-P-3300LE

ENGINES 156, 273, 275 in MODEL 216 up to 31.8.10 with CODE (233) Distronic Plus as of model year 2009/YoM 08

ENGINES 156, 272, 273, 275, 642, 629 in MODEL 221 up to 31.8.10 with CODE (233) Distronic Plus as of model year 2009/YoM 08

Fig 1: Detecting Vehicle Cutting In With Distronic Plus Activated

Courtesy of MERCEDES-BENZ USA

Detection of vehicle cutting in, with DISTRONIC PLUS activated

Distronic PLUS function requirements, general

Circuit 61 "ON" (engine running)
"ADTR_AVL" (Advanced DISTRONIC PLUS) coded in the central gateway control unit (N93)
Radar sensor system not disabled
Long range radar soiling and function test completed successfully
Electronic Stability Program (ESP) not deactivated
Driver door closed and driver seat belt plugged in
Parking brake not applied
Gear range "D" engaged
CC [TPM] push button (S40/4) in the position DISTRONIC PLUS (LIM indicator lamp (LIM ITER) off) (except code (494) USA version)

Distronic PLUS, general

Distronic PLUS sets the vehicle speed and distance from the vehicle in front according to the values set by the driver (specified speed and distance), within a range from 0 to 200 km/h.

If the lane is unoccupied (no vehicles in front), the Distronic PLUS sets the specified speed just like a 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 gear (downshift)

If the traffic situation allows the speed to be increased again, for example because the preceding vehicle accelerates or leaves the lane, DISTRONIC PLUS increases the speed back to the set target speed.

Above approx. 30 km/h the functionality of DISTRONIC PLUS is the same as that of the conventional DISTRONIC.

The signals from the CC push button switch are detected by the steering column tube module (N80) and transmitted to the radar sensors control unit (SGR) (N62/1) via the chassis CAN (CAN E).

The instrument cluster (A1) sends the selected maximum speed via the chassis CAN and central CAN (CAN F) to the radar sensors control unit. The radar sensors control unit also actuates warning chimes and displays in the instrument cluster.

DTR controller unit (A89) evaluates the radar sensor data from the DTR radar sensor (A89b1) (long range radar) and transmits the data via the vehicle dynamics CAN (CAN H) to the radar sensors control unit.

Evaluation of the radar sensors on the left and right inside, bumpers at the front (A86/1b2, A86/1b3) (short range radar) takes place via the sensor-CAN (CAN S) by the radar sensors control unit.

The radar sensors control unit then fuses the data representing identical objects from the long and short range radar.

After evaluating all the sensor data and input signals, the radar sensors control unit assumes full control of the vehicle in the longitudinal direction by transmitting signals for acceleration, deceleration, braking and gear changing to the respective control units.

The requests to accelerate or decelerate are transmitted via the chassis CAN to the CDI control unit (N3/9) (for a diesel engine) or to the ME-SFI [ME] control unit (N3/10) (for a gasoline engine).

A brake request is transmitted via the vehicle dynamics CAN to the ESP control unit (N47-5) or to the regenerative braking system control unit (N30/6) (for hybrid).

A switching request at the automatic transmission is transmitted via the chassis CAN and drive train CAN (CAN C) to the ETC control unit (N15/3) (for transmission 722.6) or to the electric controller unit (VGS) (Y3/8) (for transmission 722.9).

Function sequence for Distronic PLUS

The function sequence is described in the following steps:

Function sequence for soiling and function test
Function sequence for automatic acceleration
Function sequence for automatic braking
Function sequence for Distronic PLUS activation function sequence
Function sequence for specified speed
Function sequence for specified distance
Function sequence for special driving situations
Function sequence for automatic start-off (for Stop & Go traffic)
Function sequence for Distronic PLUS deactivation

Function sequence for soiling and function test

To ensure correct functioning, the long range radar carries out a soiling and function test at every engine start. The DISTRONIC PLUS cannot be activated if a malfunction is established or if there are no objects (for the function test) in the detection range of the long-range radar sensor.

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

Function sequence for automatic acceleration

The automatic maximum acceleration of DISTRONIC PLUS is limited to approx. 2.5 m/s² for reasons of safety and comfort.

Function sequence for automatic braking

Intervention by the brake system is limited to 40% (about 4 m/s² ) of the maximum possible braking power for reasons of safety and comfort. Driving situations requiring more than 40 % braking power are indicated to the driver visually by the DTR warning lamp (A1e59) in the instrument cluster and acoustically by a tone. This tone is an intermittent chime which advises the driver to observe the traffic situation and intervene if necessary (take over control).

The tone is shut off automatically when the situation becomes less critical; it cannot be deactivated manually.

Function sequence for Distronic PLUS activation

By pulling the CC [TPM] switch, DISTRONIC PLUS is activated with the last saved target speed provided that a target speed has already been saved since the last engine start (set). If there is no stored target speed, DISTRONIC PLUS sets the current vehicle speed as the target speed.

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

DISTRONIC PLUS can be activated from a standstill up to a speed of 200 km/h. However, at speeds <30 km/h, it can only be activated if a preceding vehicle is detected.

When a preceding vehicle is detected, it can be observed in the instrument cluster with its current speed and distance.

When stationary, DISTRONIC PLUS can only be activated if it can detect another stationary vehicle at a distance <6 m in front of it. To simplify activation when at a standstill, the driver can depress the brake pedal when activating DISTRONIC PLUS.

The message "Distronic PLUS Unavailable" appears if:

Radar sensor system is disabled
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
On-board voltage is too low

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

View of the instrument cluster for an activated DISTRONIC PLUS and vehicle immediately ahead

Fig 2: View Of Instrument Cluster For Activated Distronic Plus

Courtesy of MERCEDES-BENZ USA

When DISTRONIC PLUS is activated, the segments between the measured speed of the vehicle moving ahead and the set target speed are illuminated in the electronic speedometer (A1p8) in the instrument cluster. The orange triangle at the top of the segment ring indicates the set target speed.

The vehicle immediately ahead is shown in the multifunction display of the instrument cluster with the current distance from it in meters.

If there is no vehicle immediately ahead detected with DISTRONIC PLUS activated then no segments in the speedometer are lit up.

Function sequence for specified speed

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).

The minimum target speed that can be set is 30 km/h, while the maximum settable target speed is 200 km/h.

If DISTRONIC PLUS is activated at a speed < 30 km/h, the target speed is automatically set to 30 km/h.

If Distronic PLUS is activated at a speed between 200 and 260 km/ h, the specified speed is set automatically to the maximum permissible specified speed of 200 km/h.

Function sequence for specified distance

With the DTR distance potentiometer (S40r1, S40/4r1), the specified distance from the vehicle in front can be set in six steps between approx. 1.0 and 2.0 s, depending on vehicle speed. In the third stage 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 host vehicle and is displayed in the form of a white line on the range indicator in 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.

View of instrument cluster when the vehicle is below the specified distance

Fig 3: View Of Instrument Cluster When Vehicle Ahead Is Below Specified Distance

Courtesy of MERCEDES-BENZ USA

If the preceding vehicle comes within the set target distance, DISTRONIC PLUS reduces the speed.

In driving situations requiring more than 40% braking power (dangerous situations), the DTR warning lamp in the instrument cluster lights up and the takeover tone signals to the driver to carefully observe driving situation and to intervene himself by measured heavy braking or steering if necessary.

Function sequence for special driving situations

If the driver accelerates on his own initiative faster than the acceleration defined by DISTRONIC PLUS, then DISTRONIC PLUS does not shut down, but changes to the passive state. The message "Distronic PLUS passive" appears on the multifunction display of the instrument cluster, and in this case no distance control from the vehicle in front takes place. When the driver releases the accelerator pedal (vehicle speed drops), DISTRONIC PLUS stabilizes at the set target speed again and distance control is reactivated.
The system does not operate for stationary targets (e.g. vehicles) unless a preceding vehicle is tracked to a standstill.
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, an intermittent takeover tone and the DTR warning lamp warn the driver about the impending collision.
If the preceding vehicle leaves the same lane at a speed <30 km/h, DISTRONIC PLUS is deactivated and a deactivation tone sounds.

Fig 4: Function Sequence For Special Driving Situations
Courtesy of MERCEDES-BENZ USA

Stop & Go traffic (traffic jam)

Function sequence for automatic start-off (for Stop & Go traffic)

DISTRONIC PLUS-controlled start-off in stop & go traffic occurs only after the driver has acknowledged it by pulling the CC [TPM] switch or by briefly operating the accelerator pedal.

To facilitate operation of the system, the driver can depress the brake pedal while stationary without deactivating DISTRONIC PLUS. However, the driver must release the brake pedal in order to command start-off under DISTRONIC PLUS control.

Function sequence for Distronic PLUS deactivation

DISTRONIC PLUS is deactivated if:

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 depressed (except when stationary)
Parking brake is actuated
Gear range "N" or "R" engaged
A vehicle in front moving at a speed of <30 km/h is no longer detected (lost)
ESP operates
ESP switched off
ESP deactivated (a fault)
Radar function no longer available
Ignition is switched off (circuit 15 OFF)

Function sequence for Distronic PLUS electrical	Model 216	PE30.30-P-2053-97CAA
Function sequence for Distronic PLUS electrical	Model 221	PE30.30-P-2053-97SAA
Component description for instrument cluster	A1 Model 216.3, 221.0/1 except 221.095/195 HYBRID	GF54.30-P-6000LE
Component description for instrument cluster	Model 221.095/195 HYBRID	GF54.30-P-6000LEH
Component description for DTR controller unit	A89 up to AEJ 09/model refinement package	GF30.30-P-3210LE
Component description for DTR controller unit	as of AEJ 09/model refinement package	GF30.30-P-3210LEB
Component description for CDI control unit	N3/9 Model 221.0/1 with engine 629.9	GF07.16-P-6000OA
Component description for CDI control unit	Model 221.0/1 with engine 642.9	GF07.16-P-6000OHL
Component description for ME-SFI [ME] control unit	N3/10 Model 216.3, 221.0/1 with engine 156	GF07.61-P-6000MAS
	Model 221.0/1 with ENGINE 272 except model 221.095/195 HYBRID with engine 272.974	GF07.61-P-6000MIS
	Model 221.095/195 HYBRID with engine 272.974	GF07.61-P-6000MEH
	Model 216.3, 221.0/1 with engine 273	GF07.61-P-6000MLS
	Model 216.3, 221.1 with engine 275	GF07.61-P-6000MOS
Component description for electronic transmission control control unit	N15/3 Model 216.3, 221.1 with transmission 722.6	GF27.60-P-5164ACS
Component description for regenerative braking system control unit	N30/6 Model 221.095/195 HYBRID	GF42.22-P-1100LEH
Component description for ESP control unit	N47-5 Model 216.3, 221.0/1 except 221.095/195 HYBRID	GF42.45-P-5118LE
Component description for radar sensors control unit	N62/1	GF30.30-P-3301LE
Component description for steering column tube module	N80 Model 216.3, 221.0/1	GF54.21-P-6050LE
Component description for fully integrated transmission control unit	Y3/8n4 Model 216.3, 221.0 /1 with transmission 722.9	GF27.60-P-5165AHS