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Plus Light intelligent cruise control, function - GF30.30-P-3400LE

ENGINES 156, 272, 273, 275, 629, 642 in MODEL 221 up to 31.8.10 with CODE (239) Autonomous intelligent cruise control Plus Light as of model year 2010/YoM 09 model refinement package 

Autonomous intelligent cruise control Plus Light in operation 

Fig 1: Autonomous Intelligent Cruise Control Plus Light Operation Diagram
G07587476Courtesy of MERCEDES-BENZ USA

Function requirements for Autonomous intelligent cruise control Plus Light, general 

Plus Light intelligent cruise control, general 

The intelligent cruise control regulates the speed and the distance to the vehicle ahead according to the driver's specifications (target speed and required distance) in the range of 0 to 200 km/h.

In doing so the autonomous intelligent cruise control 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:

If the traffic situation allows an increase in speed as the vehicle immediately ahead has accelerated or left the lane, for example, the autonomous intelligent cruise control 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 the cornering ends or the target destination is recognized again.

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 actuates displays in the instrument cluster and warning tones.

The DTR control unit (A89n1) 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 radar sensors control unit.

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 via the chassis CAN.

The requests to accelerate or decelerate are transmitted via the chassis CAN to the CDI control unit (N3/9) (for diesel engines) or to the ME-SFI [ME] control unit (N3/10) (for gasoline engines). A braking request is transmitted to the ESP control unit (N47-5) via the vehicle dynamics CAN.

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 Plus Light intelligent cruise control 

The function sequence is described in the following points:

Function sequence for soiling and function test 

The DTR control unit performs a soiling and function test of the radar sensor to ensure smooth functioning of the radar system after each engine start. The intelligent cruise control 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 "Intelligent cruise control currently unavailable" appears in the multifunction display (A1p13) of the instrument cluster.

Function sequence for automatic acceleration 

For reasons of safety and comfort, the automatic acceleration of the intelligent cruise control is limited to about 2.5 m/s2 .

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 that require more than 40 % braking power are signaled by the driver optically by the DTR indicator lamp (A1e59) in the instrument cluster and acoustically by an intermittent warning tone.

This interval warning tone requires the driver to observe the traffic situation and to intervene himself if necessary

The intermittent warning tone is turned off automatically when the situation becomes less critical and cannot be deactivated manually.

Activating Plus Light intelligent cruise control 

The intelligent cruise control can be activated at any speed from > 0 to 260 km/h. However, at speeds <30 km/h, it can only be activated if a preceding vehicle is detected.

By pulling the CC [TPM] switch, the intelligent cruise control 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 specified speed has been stored, the intelligent cruise control sets the current vehicle speed as the specified speed.

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

IMPORTANT The message "Distronic PLUS Unavailable" appears if:

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

View of instrument cluster when intelligent cruise control is activated 

Fig 2: View Of Instrument Cluster With Intelligent Cruise Control Activated
G07587477Courtesy of MERCEDES-BENZ USA

When the intelligent cruise control 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 vehicle immediately ahead is shown in the multifunction display of the instrument cluster with the current distance from it in meters. The orange triangle at the top of the segment ring indicates the set target speed.

If there is no vehicle immediately ahead detected with intelligent cruise control 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 and the maximum target speed 200 km/h.

If the intelligent cruise control is activated at a speed of <30 km/h, the maximum speed is automatically set to 30 km/h. If the intelligent cruise control 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 (N72r1), the specified distance from the vehicle in front can be set in six steps between about 1.0 and 2.0 s, depending on vehicle speed. In the third stage, at a speed of 100 km/h, this is equivalent to a specified distance of approx. 42 m. The specified distance is converted from seconds to meters to match the host vehicle's speed and then shown in the form of a white line in the instrument cluster's multifunction display.

The target distance in the distance indicator matches the current vehicle speed without the driver having to adjust the DTR distance potentiometer.

IMPORTANT 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 Vehicle Distance In Instrument Cluster
G07587478Courtesy of MERCEDES-BENZ USA

If the set target speed to the vehicle ahead falls short, the intelligent cruise control 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 intermittent warning tone signals to the driver to carefully observe the driving situation and to intervene himself by measured heavy braking or steering as necessary.

Function sequence for special driving situations 

Function sequence for stopping behind target vehicle 

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 switching off tone through the intelligent cruise control switching off. The set braking torque at the point in time of switching off is slowly reduced after the switching off tone.

The intelligent cruise control is already deactivated in the following situations before reaching a standstill:

Function sequence for deactivating intelligent cruise control 

The intelligent cruise control mode is deactivated if:

REFER TO SYSTEM WIRING DIAGRAMS Electrical function schematic for intelligent cruise control Plus Light   PE30.30-P-2054-97SAA
  Component description for instrument cluster A1
Model 221.0/1 except 221.095/195
GF54.30-P-6000LE
  Component description for DTR controller unit A89 GF30.30-P-3210LEC 
  Component description for CDI control unit N3/9
Model 221.0/1 with engine 629.9
GF07.16-P-6000OA
Model 221.0/1 with engine 642.9 GF07.16-P-6000OHL
  Component description for ME-SFI [ME] control unit N3/10
Model 221.0/1 with engine 156
GF07.61-P-6000MAS
Model 221.0/1 with engine 272 GF07.61-P-6000MIS
Model 221.0/1 with engine 273 GF07.61-P-6000MLS
Model 221.1 with engine 275 GF07.61-P-6000MOS
  Component description for electronic transmission control control unit N15/3
Model 221.1 with transmission 722.6
GF27.60-P-5164ACS
  Component description for ESP control unit N47-5
Model 221.0/1
GF42.45-P-5118LE
  Component description for radar sensors control unit N62/1 GF30.30-P-3301LEC 
  Component description for steering column tube module N80
Model 221.0/1
GF54.21-P-6050LE
  Component description for central gateway control unit N93
Model 221.0 / 1
GF54.21-P-4170LE
  Component description for fully integrated transmission control unit Y3/8n4
Model 221.0/1 with transmission 722.9
GF27.60-P-5165AHS