necessary for the system to start the combustion engine even when the vehicle is not moving. With prolonged driving in traffic jams, the combustion engine will be switched on and off to charge the high-voltage battery for the following start-stop phase.
Sailing
If the accelerator is not depressed and the lever is in Drive (D), the internal 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 vehicles power requirements. Even in this case, the rev counter in the instrument cluster displays zero engine speed (0 engine revolutions). 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 tachometer will show zero engine speed (zero engine revolutions). The instrument cluster powermeter shows zero.
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 High-voltage battery 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. 261 Energy flow display (Variant 1). Left: Instrument cluster. Right: Infotainment System.
WARNING
High voltage systems in the engine compartment can cause electrical shocks or even electrocution, severe burns, other serious injuries, and even death!
x Never short-circuit the electrical system. Be especially careful when using jumper cables. The vehicle's battery could explode!
x To reduce the risk of electrical shock and personal injury while the engine is running or being started:
– Never touch ignition cables. Never touch other components of the high-voltage electronic ignition system.
– Never touch the wiring of the HID – High Intensity Discharge (Xenon) headlights.
x Read and heed the important information and warnings on cleaning the engine
compartment ⇒ Cleaning the engine compartment.
WARNING
Moving parts in the engine compartment can cause serious personal injury on contact.
x Never reach into the area around or touch the radiator fan. Contact with the blades can cause serious personal injury. Always remember that the radiator fan is temperature-controlled and can come on suddenly even when the engine has been switched off for a while and the key has been removed from the ignition.
x If you have to perform a check or repair when the engine is running, there are more risks from the rotating parts, such as the drive belts, alternator, radiator fan, etc., and from the high-voltage ignition system. Always use extreme care.
– Always make sure that jewelry, loose clothing and long hair do not get caught in rotating engine parts. Before starting any work remove your jewelry, take off your necktie, tie back and cover your hair, and do not wear clothing that can hang down and get caught in moving engine parts.
– Always use extreme caution if the accelerator pedal has to be depressed to perform a check. The vehicle will start to move even if the parking brake is on.
x Never leave any objects in the engine compartment, for example cleaning rags and tools. Objects left behind can cause malfunctions, engine damage, and even fires.
WARNING
Operating fluids and some materials in the engine compartment can catch fire easily, causing burns and other serious personal injuries!
x Do not smoke.
x Never work next to open flames or sparks.
x Never pour or spill operating fluids or other flammable liquids on the engine. These fluids can ignite on hot engine parts and cause injuries.
x If work on the fuel system or the electrical system is necessary:
– Always disconnect the 12 Volt vehicle battery. Make sure the vehicle is unlocked when you disconnect the battery, or the alarm will go off. Never touch the electrical wiring of the ignition system.
– Never work near heaters, water heaters, or other open flames.
x Always have a functional, approved fire extinguisher nearby.
