681-2. Hybrid system
GS450h_OM_OM30E99U_(U)
■Conditions in which the gasoline engine may not stop
The gasoline engine starts and stops automatically. However, it may not stop automati-
cally in the following conditions:
●During gasoline engine warm-up
●During hybrid battery (traction battery) charging
●When the temperature of the hybrid battery (traction battery) is high or low
●When the heater is switched on
■Charging the hybrid battery (traction battery)
As the gasoline engine charges the hybrid battery (traction battery), the battery does not
need to be charged from an outside source. However, if the vehicle is left parked for a
long time the hybrid battery (traction battery) will slowly discharge. For this reason, be
sure to drive the vehicle at least once ever y few months for at least 30 minutes or 10
miles (16 km). If the hybrid battery (tractio n battery) becomes fully discharged and you
are unable to start the hybrid system, contact your Lexus dealer.
■Charging the 12-volt battery
P. 4 5 5
■After the 12-volt battery has discharged or when the terminal has been removed and
installed during exchange, etc.
The gasoline engine may not stop even if the ve hicle is being driven by the hybrid battery
(traction battery). If this continues for a few days, contact your Lexus dealer.
■Sounds and vibrations spec ific to a hybrid vehicle
There may be no engine sound or vibration even though the vehicle is able to move with
the “READY” indicator is illuminated. For safety, apply the parking brake and make sure
to shift the shift lever to P when parked.
The following sounds or vibrat ions may occur when the hybrid system is operating and
are not a malfunction:
●Motor sounds may be heard from the engine compartment.
●Sounds may be heard from the hybrid battery (traction battery) behind the rear seats
when the hybrid system starts or stops.
●Relay operating sounds such as a snap or soft clank will be emitted from the hybrid bat-
tery (traction battery), behind the rear seats, when the hybrid system is started or
stopped.
●Sounds from the hybrid system may be heard when the trunk lid is open.
●Sounds may be heard from the transmission wh en the gasoline engine starts or stops,
when driving at low speeds, or during idling.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard due to regenerative braking when the brake pedal is depressed
or as the accelerator pedal is released.
●Vibration may be felt when the gasoline engine starts or stops.
●Cooling fan sounds may be heard from the air intake vents on the both sides of the rear
seatback.