2012 Lexus HS250h charging

448
4-3. Do-it-yourself maintenance
HS250h_U_75050U
■Before recharging
When recharging, the 12-volt battery produces hydrogen gas which is flammable
and explosive. Therefore, observe the following precautions before recharging:
●If recharging with the 12-volt battery installed on the vehicle, be sure to discon-
nect the ground cable.
●Make sure the power switch on the charger is off when connecting and discon-
necting the charger cables to the 12-volt battery.
■After recharging/reconnecting the 12-volt battery
●Unlocking the doors using the smart key system may not be possible immedi-
ately after reconnecting the 12-volt battery. If this happens, use the wireless
remote control or the mechanical key to lock/unlock the doors.
●Start the hybrid system with the “POWER” switch in ACCESSORY mode. The
hybrid system may not start with the “POWER” switch turned OFF. However,
the hybrid system will operate normally from the second attempt.
●The “POWER” switch mode is recorded by the vehicle. If the battery is recon-
nected, the vehicle will return the “POWER” switch mode to the status it was in
before the battery was disconnected. Make sure to turn off the power before
disconnect the battery. Take extra care when connecting the battery if the
“POWER” switch mode prior to discharge is unknown.
■Exterior
Make sure that the 12-volt battery terminals are not corroded and
that there are no loose connections, cracks or loose clamps.
Te r m i n a l s
Hold-down clamp

450
4-3. Do-it-yourself maintenance
HS250h_U_75050U
CAUTION
■Emergency measures regarding electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immediate medi-
cal attention. If possible, continue to apply water with a sponge or cloth while
traveling to the nearest medical facility.
●If electrolyte gets on your skin
Wash the affected area thoroughly. If you feel pain or burning, get medical atten-
tion immediately.
●If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the clothing and
follow the procedure above if necessary.
●If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medical attention imme-
diately.
■When replacing the 12-volt battery
Use a 12-volt battery designed for this vehicle. Failure to do so may cause gas
(hydrogen) to enter the passenger compartment, causing a fire or explosion.
For replacement of the 12-volt battery, contact your Lexus dealer.
NOTICE
■When recharging the 12-volt battery
Never recharge the 12-volt battery while the hybrid system is operating. Also, be
sure all accessories are turned off.

502
HS250h_U_75050U
5-2. Steps to take in an emergency
If a warning light turns on or a warning buzzer sounds...
Stop the vehicle immediately. Continuing to drive the vehicle may be dangerous.
The following warning indicates a possible problem in the brake system.
Immediately stop the vehicle in a safe place and contact your Lexus
dealer.
*: Brake system warning buzzer
When there is a possible problem that could affect braking performance, the
warning light will come on and a warning buzzer will sound.
Parking brake engaged warning buzzer
→ P. 5 1 6
Stop the vehicl e immediately.
The following warning indicates the possibility of damage to the vehicle
that may lead to an accident. Immediately stop the vehicle in a safe place
and contact your Lexus dealer.
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Brake system warning li ght and warning buzzer*
•Low brake fluid
• Malfunction in the brake system This light also comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released the system is operating normally.
Warning lightWarning light/Details
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
Calmly perform the following actions if any of the warning lights comes on
or flashes. If a light comes on or flashes, but then goes off, this does not nec-
essarily indicate a malfunction in the system. However, if this continues to
occur, have the vehicle inspected by your Lexus dealer.

5
When trouble arises
549
5-2. Steps to take in an emergency
HS250h_U_75050U
■Starting the hybrid system when the 12-volt battery is discharged
The hybrid system cannot be started by push-starting.
■To prevent 12-volt battery discharge
●Turn off the headlights and the audio system while the hybrid system is off.
●Turn off any unnecessary electrical components when the vehicle is running at a
low speed for an extended period, such as in heavy traffic.
■When the 12-volt battery is discharged
●The hybrid system may not start. (→P. 4 4 8 )
●If the 12-volt battery is depleted with the shift position in P, it will not be possible
to shift out of P. In this case, the vehicle cannot be towed without lifting both
front wheels because the front wheels are locked by the parking lock.
(→ P. 4 9 5 )
●When the 12-volt battery is reconnected, start the hybrid system, depress the
brake pedal, and confirm that it is possible to shift into each shift position.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gradually even when the
vehicle is not in use, due to natural discharge and the draining effects of certain
electrical appliances. If the vehicle is left for a long time, the 12-volt battery may dis-
charge, and the hybrid system may be unable to start. (The 12-volt battery
recharges automatically while the hybrid system is operating.)
Make sure the “READY” indicator comes on. If the indicator
does not come on, contact your Lexus dealer.
Once the hybrid system has started, remove the jumper cables
in the exact reverse order from which they were connected.
Close the exclusive jump starting terminal cover and reinstall
the fuse box cover.
Once the hybrid system starts, ha ve the vehicle inspected at your
Lexus dealer as soon as possible.

550
5-2. Steps to take in an emergency
HS250h_U_75050U
CAUTION
■Avoiding battery fires or explosions
The flammable gas that may be generated by the assisting vehicle battery may
catch fire and explode. Make sure to observe the following to prevent fire or sparks.
●Make sure each jumper cable is connected to the correct terminal and that it is
not unintentionally in contact with any part other than the intended terminal.
●Do not allow the other end of the jumper cable connected to the “+” terminal to
come into contact with any other parts or metal surfaces in the area, such as
brackets or unpainted metal.
●Do not allow the + and - clamps of the jumper cables to come into contact with
each other.
●Do not allow open flame or use matches, cigarette lighters or smoke near the
battery.
■12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic electrolyte, while
related parts contain lead and lead compounds. Observe the following precautions
when handling the 12-volt battery:
●When working with the 12-volt battery, always wear safety glasses and take care
not to allow any battery fluids (acid) to come into contact with skin, clothing or the
vehicle body.
●Do not lean over the 12-volt battery.
●In the event that battery fluid comes into contact with the skin or eyes, immedi-
ately wash the affected area with water and seek medical attention. Place a wet
sponge or cloth over the affected area until medical attention can be received.
●Always wash your hands after handling the battery support, terminals, and other
battery-related parts.
●Do not allow children near the 12-volt battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, continued use may cause the 12-volt battery to
emit a malodorous gas, which may be detrimental to the health of passengers.
■When replacing the 12-volt battery
→P. 4 5 0

5
When trouble arises
551
5-2. Steps to take in an emergency
HS250h_U_75050U
NOTICE
■Exclusive jump starting terminal precaution
The exclusive jump starting terminal is to be used when charging the 12-volt battery
from another vehicle in an emergency. It cannot be used to jump start another vehi-
cle.
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in
the cooling fans or belt.

565
6-1. Specifications
6
Vehicle specifications
HS250h_U_75050U
Ignition system
Electrical system
Hybrid transaxle
*: The fluid capacity is a reference quantity. If replacement is necessary, contactyour Lexus dealer.
Spark plug
Make
GapDENSO SK20R11
NGK IFR6A11
0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust spark plug gap.
12-volt battery
Open voltage* at
68 °F (20 °C):12.6  12.8 V Fully charged
12.2 
12.4 V Half charged
11.8 
12.0 V Discharged
(*: Voltage checked 20 minutes after the hybrid sys-
tem and all the lights are turned off)
Charging rates5 A max.
Fluid capacity *4.4 qt. (4.2 L, 3.7 Imp. qt.)
Fluid typeTo y o t a G e n u i n e AT F W S

623
Alphabetical index
HS250h_U_75050U
Warning buzzersBrake system ....................................... 502
Open door ..........................................505
Seat belt reminder ............................505
Warning lights AFS OFF ...............................................503
Anti-lock brake system ..................503
Brake assist system ..........................503
Brake system ....................................... 502
Charging system ............................... 502
Cruise control .....................................503
Electric power steering
warning light .....................................503
Electronic engine control
system..................................................503
High coolant temperature ............ 502
LKA ..........................................................503
Low fuel level.......................................505
Low tire pressure ..............................505
Malfunction indicator lamp ..........503
Master warning light ........................505
Open door ...........................................505
Pre-collision system .........................503
Pretensioner.........................................503
Radar cruise co ntrol ........................503
Seat belt reminder light ..................505
Slip indicator ........................................503
SRS airbags ..........................................503
Tire pressure warning light...........505 Warning messages
Cruise control....................................... 513
Dynamic radar cruise control .........................................513, 516
Electric power steering system ................................................... 513
Engine oil maintenance ................... 516
Engine oil pressure ............................ 512
EV drive mode..................................... 516
Headlight................................................. 513
Hood ......................................................... 516
Hybrid system....................................... 512
Intuitive parking assist .............513, 516
Key.............................................................524
Lane-Keeping Assist ......................... 516
Moon roof .............................................. 516
Open door ............................................. 516
Parking brake ....................................... 516
Pre-collision system.................513, 516
Smart access system with push start ............................................524
Tire pressure warning
system ................................................... 516
Trunk ......................................................... 516
Washer fluid .......................................... 516
Washer
Checking ...............................................446
Preparing and checking before winter ................................... 258
Switch.......................................................204
Washing and waxing ............................ 416
Weight Cargo capacity ................................... 257
Load limits ............................................. 257
Weight.................................................... 560
*: For vehicles with a navigation system, refer to “Navigation System Owner’s Manual”.
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