The start/stop function reduces fuel consumption, which in turn can contribute to an environmentally conscious driving style and reduced emissions.
Points to remember when using the start/stop functionFor the start/stop function to work requires that a number of conditions are met.
The start/stop function is not activatedOne or more criteria may mean that the engine is not switched off/the function is not activated.
- the driver has not fastened the seatbelt
- the car has not been able to reach a speed of approx. 10 km/h (6 mph) after starting or the function has been activated a number of times successively
- the engine has not reached normal operating temperature
- the windscreen’s electric heating is activated
- the environment in the passenger compartment deviates from the set values
- the driver is making large steering wheel movements
- the road is very steep
- the bonnet is opened
- the ABS system has been activated
- in the event of heavy braking (even without the ABS system having been activated)
- the capacity of the starter battery has fallen below the minimum permissible level
- many starts during a short period of time have activated the starter motor’s thermal protection
- the exhaust system’s particulate filter is full
- a trailer is connected to the car’s electrical system.
NoteHigh current take-off may lead to battery capacity falling below the lowest permitted level, which temporarily limits the start/stop function. The engine then starts automatically without the driver lifting his/her foot from the brake pedal.
The start/stop function is not deactivatedOne or more criteria may mean that the engine is not started/the function is not deactivated.
- the driver has not fastened the seatbelt
- gear position P is engaged and the driver door is open.
The start/stop function is deactivated without the brake pedal being releasedIn the following cases, the function may be deactivated and the engine started without the driver releasing the brake pedal:
- high humidity in the passenger compartment forms misting on the windows
- the environment in the passenger compartment deviates from the set values
- repeated pumping of the brake pedal
- the bonnet is opened
- the capacity of the starter battery has fallen below the minimum permissible level
- the driver’s seatbelt is unbuckled and the gear selector is in position D or N
- the gear selector is moved from position D to position R or M
- the driver door is opened with the gear selector in position D.
WarningDo not open the bonnet when the start/stop function is active. Switch off the engine normally before raising the bonnet.
Activating and deactivating the start/stop function
The start/stop function is available when the car is started. When the function is activated, the engine is switched off temporarily. The engine then starts automatically when the function is deactivated or when the car requires this.
Activating the start/stop function
Depress and hold the brake pedal depressed.
The start/stop function is activated and the engine is switched off.
Note
- In some cases, the start/stop function is activated before the car is completely stationary.
- When adaptive cruise control or Pilot Assist is activated, the start/stop function is activated for a few seconds after the car is completely stationary.
NoteAll of the car’s normal systems, such as lighting and radio, work normally even when the start/stop function is activated.
However, some equipment may have temporarily reduced function, such as the climate control’s fan speed or loudspeaker volume.
Deactivating the start/stop function
Release the brake pedal or gently depress the accelerator pedal.
The start/stop function is deactivated and the engine starts.
NoteWhen the start/stop function is deactivated and:
- the function for automatic braking when stationary (Auto hold) is activated, start of the engine is delayed until the accelerator pedal is depressed
- adaptive cruise control or Pilot Assist is activated, the engine starts when the accelerator pedal is depressed or by pressing the
- the car is facing uphill, hill start assist (HSA) engages to prevent the car from rolling backwards
- the car is facing downhill, release the brake pedal slightly. A small increase in speed starts the engine.
Symbols in the driver display
The driver display’s tachometer indicates when the start/stop function is available, active or unavailable.
| Symbol | Specification |
|---|---|
| | White – the function is available. |
| | Green – the function is activated. |
| | Grey – the function is not available. |
If no symbol is shown in the driver display, the function is disabled.