Sailing
If the accelerator is not depressed and the lever is in position D, the combustion engine is switched off, even at higher speeds. The vehicle then decelerates slower than conventional vehicles. This feature can be used to help reduce fuel consumption when you keep traffic conditions in mind and can anticipate the vehicle's power requirements. The instrument cluster powermeter shows zero.
Brake energy regeneration (Recuperation/charge)
When the vehicle brakes, the electrical energy is generated by the electric motor, which works as an alternator and charges the high-voltage battery. The same thing occurs while the vehicle is coasting to a stop or driving downhill.
Energy regeneration is shown in the instrument cluster display or on the Infotainment System screen. The combustion engine may be switched off automatically in this situation. The instrument cluster powermeter registers below zero.
When the high voltage battery is fully charged, there is no brake energy recuperation, and therefore no engine braking. Recuperation and engine braking are also automatically reduced if the vehicle detects that the road conditions do not permit sufficient contact between the wheels and the road surface.
Automatic starting - combustion engine
The combustion engine is started automatically in a number of situations.
x Engine temperature is too low.
x Catalytic converter temperature is too low.
x The high-voltage battery requires recharging.
x High-voltage battery is being charged at high rate when decelerating. The high-voltage battery cannot absorb any more energy and for this reason the electric motor cannot brake the vehicle. The combustion engine comes on to help slow the vehicle down (engine brake).
x Engine hood is open.
x Leaving the vehicle when the electric motor is still “live”. The status of the electric motor is not always obvious, particularly when the combustion engine is not running. The combustion engine will therefore start if the driver's safety belt is unlatched or the driver's door is opened when the transmission is in Park (P) or Neutral (N), Warning when leaving the vehicle.
Energy flow display
Fig. 125 Energy flow display. A: Instrument cluster. B: Infotainment System.