The Auto Start/Stop function helps save fuel. The system switches off the engine during a stop, for instance in traffic jam or at traffic lights. Drive-ready state remains on despite the engine being stopped. The engine starts automatically for driving off.
The Auto Start/Stop function switches to standby state whenever the engine is started using the Start/Stop button.
The function is activated at low speeds.
Engine stop: Functional requirements
The engine is switched off automatically when stopping under the following conditions:
- The selector lever is in selector lever position D.
- The brake pedal remains depressed while the vehicle is at a standstill or the vehicle is held by Automatic Hold.
- The driver's seat belt is buckled or the driver's door is closed.
Manual engine stop
If the vehicle is equipped with the M Steptronic Sport transmission, the engine can be switched off manually if it did not switch off automatically when the vehicle stopped:
- By quickly depressing the brake pedal from the current position.
- By engaging selector lever position P.
When all functional preconditions are fulfilled, the engine switches off.
Automatic climate control with engine switched off
The automatic climate control system's air flow is reduced when the engine is switched off.
Display in the instrument cluster
The READY indicator on the instrument cluster shows that the Auto Start/Stop function is ready to start the engine automatically.
Starting the engine: Functional requirements
When driving off, the engine starts automatically if the following requirements are met:
- By releasing the brake pedal.
- If Automatic Hold is activated: Press the accelerator pedal.
Driving off with the Auto Start/Stop function
To drive off, accelerate normally after starting the engine.
Safety mode
If one of the following conditions is met, the engine will not start automatically after it has been stopped automatically:
- The driver’s seat belt is unbuckled, and the driver’s door is open.
- The hood has been unlocked.
Some indicator lights illuminate for a varied length of time.
The engine can only be started using the Start/Stop button.
Deactivating the system manually
In certain driving situations, e.g., traffic jams, it may be helpful to deactivate Auto Start/Stop manually. The engine will then no longer switch off automatically.
If this function is deactivated while the engine is being stopped automatically, the engine will start.
Perform the following via iDrive screen to manually activate or deactivate Auto Start/Stop:
1. Apps menu
2. "Vehicle"
3. "Driving settings"
4. "Drivetrain and chassis"
5. "Activate Auto Start/Stop"
6. Select the desired setting.
Perform the following via selector lever position or drive mode to deactivate Auto Start/Stop:
- In selector lever position S.
- In selector lever position L.
- In driving mode "SPORT PLUS".
Switching off the vehicle during an automatic engine stop
If the engine stops automatically, the vehicle can be parked safely, for example to leave it.
- Press the Start/Stop button.
- Drive-ready state is switched off.
- Standby state is switched on.
- Selector lever position P is engaged automatically.
- Set the parking brake.
Automatic deactivation
If no driver is detected, the Auto Start/Stop function is deactivated automatically in certain situations for safety purposes.
Note: Auto Start/Stop only lasts for one drive cycle. It will need to be reactivated every time.
