Stop/Start system

The Stop/Start system saves fuel and reduces exhaust emissions. When conditions allow, it switches off the engine as soon as the vehicle is stationary or moving slowly, for example at a red light or in traffic. It restarts the engine automatically as soon as the driver depresses the clutch pedal.

Using a battery sensor, the Auto Stop function is only activated if the battery is sufficiently charged to ensure restarting.

Activation

The Stop/Start system is available as soon as the engine starts, the vehicle is moving and the conditions described in this section are met.

Deactivation

To switch off the Stop/Start system manually, press the eco button. Deactivation is indicated by the button LED turning off.

Auto Stop

When the vehicle is moving slowly or stationary, activate Auto Stop as follows:

• Depress the clutch pedal
• move the selector lever to neutral
• release the clutch pedal.

The engine will switch off while the ignition remains on.

An Auto Stop is indicated by the needle at the AUTOSTOP position on the tachometer.

During an Auto Stop, braking performance and heater performance are maintained.

Notice

Steering assistance may be reduced during an Auto Stop.

Conditions for Auto Stop

The Stop/Start system checks whether all of the following conditions are met.

• The Stop/Start system has not been switched off manually,
• the hood is fully closed,
• the driver's door is closed or the driver's seat belt is fastened,
• the battery is sufficiently charged and in good condition,
• the engine is warm,
• the engine coolant temperature is not too high,
• the exhaust gas temperature is not too high, for example after driving the vehicle under high engine load,
• the ambient temperature is above -5 °C,
• the climate control system allows Auto Stop,
• the brake vacuum is sufficient,
• the diesel particulate filter self-cleaning function is not activated,
• the vehicle has been driven at walking pace since the last Auto Stop

Otherwise, Auto Stop will be inhibited.

Certain climate control settings may prevent Auto Stop.

Refer to the climate control chapter for more detailed information 137.

The Auto Stop function may be temporarily unavailable immediately after driving on a motorway.

Breaking in a new vehicle 145.

Battery discharge protection

To ensure reliable engine restarting, the Stop/Start system incorporates several battery discharge protection functions.

Energy-saving measures

During Auto Stop, several electrical features such as the auxiliary electric heater or the rear window heater are switched off or set to energy-saving mode. The climate control blower speed is reduced to save energy.

Restarting the engine manually

Depress the clutch pedal to restart the engine.

The engine start is indicated by the tachometer needle moving to the idle position.

If the selector lever is moved out of neutral before the clutch pedal has first been depressed, the indicatorlights up or a
symbol appears in the driver information centre.

Indicator light 96.

Restarting the engine with the Stop/Start system

The selector lever must be in neutral for an automatic restart to be possible.

If one of the following conditions occurs during Auto Stop, the Stop/Start system will automatically restart the engine:

• The Stop/Start system is deactivated manually,
• the bonnet is open,
• the driver's seat belt is not fastened and the driver's door is open,
• the engine temperature is too low,
• the battery charge level is below the defined level,
• the brake vacuum is insufficient,
• the vehicle is driven at walking pace,
• the climate control system requests engine start,
• climate control is activated manually

If the bonnet is not fully closed, a warning message is displayed in the driver information centre.

If an electrical accessory, e.g. a portable CD player, is connected to the power outlet, a brief voltage drop may be noticed when restarting.