Page: 66

Auto Start/Stop Function

When the vehicle stops, e.g. at a traffic light or in a traffic jam, the engine automatically stops, provided all the requirements for the auto stop function are met. In addition, the engine can also stop automatically when the vehicle stops while moving at walking speed. In this way, the automatic Start/Stop function helps to save fuel.

The ignition remains on, even when the engine is stopped automatically. All safety functions continue to operate.

Prerequisites for the auto engine stop

1. Auto Start/Stop function switched on.
2. Hood closed.
3. Brake pedal pressed.
4. PDK selector lever in position D, N or P or manually selected gear 1 or 2.
5. Engine, transmission, and air conditioning have reached operating temperature.
6. The vehicle has traveled at least at walking speed since the last auto engine stop.

Stopping and starting the engine

Stopping the engine

1. Brake the vehicle with the footbrake.
2. Press and hold the footbrake.
   – or –
   While stationary, move the PDK selector lever to position P.
   

Information
The HOLD function can be activated by quickly flooring the pressed brake pedal while the vehicle is stationary. This keeps the vehicle at an engine stop without the brake pedal having to be pressed continuously.

1. Please see chapter "HOLD Function: Drive-off Assistant, Standstill Management" on page 131.

The engine starts automatically when the accelerator pedal is pressed or if the engine needs to be started.

Information
If the adaptive cruise control (ACC) is switched on, the engine stops automatically when the vehicle is stationary, if the vehicle in front also comes to a halt.

The vehicle is held in a stationary position by the HOLD function.

Starting the engine

1. Place PDK selector lever in position P, D, N or manually selected drive position 1 or 2.

• Release the footbrake (not in selector lever position P).
  – or –
  Press the accelerator pedal.
  – or –
  Move the steering wheel.
  – or –
  Select PDK selector lever position R.
  You can move off as normal.

Information
The engine will start automatically in certain situations, e.g. if the vehicle starts rolling or to maintain a comfortable climate.

Information
If the adaptive cruise control (ACC) is active, the engine starts automatically when the vehicle in front moves off again.

Reaction after leaving the vehicle (selector lever position P selected)
If you leave the vehicle after the engine is stopped automatically and when PDK selector-lever position P is engaged (driver's door is opened and footbrake is released) in order to open the garage door, for example, the engine will not start automatically.

Auto Start Stop mode is resumed if the driver closes the driver’s door and presses the brake within 30 seconds after leaving the vehicle.

If any of these prerequisites is not satisfied, the vehicle must be started manually. A message stating that the engine has to be started manually appears on the multi-function display.

1. Please see chapter "Warning and Information Messages" on page 327.

Reaction after leaving the vehicle (selector-lever position D, M or N selected)
If you leave the vehicle after the engine has stopped automatically and when PDK selectorlever position D, M or N is engaged (driver’s door is opened and footbrake is released), the engine will start automatically to remind the driver that the Auto Start Stop function is still active.