Lexus HS250h 2010 Operating the lights and windshield wipers / LEXUS 2010 HS250H OWNERS MANUAL (OM75006U)
Page 531 of 608
5
When trouble arises
531
5-2. Steps to take in an emergency
Emergency start function
When the hybrid system does not start, the following steps can be used as 
an interim measure to start the hybrid system if the “POWER” switch is 
functioning normally:Set the parking brake.
Turn the “POWER” switch to ACCESSORY mode.
Press and hold the “POWER” swit ch for abou
 t 15 seconds while 
depressing the brake pedal firmly.
Even if the hybrid system can be started using the above steps, the system 
may be malfunctioning. Ha
 ve the vehicle inspected by your Lexus dealer.
■The interior lights and headlights do not turn on, or the horn does 
not sound.
One of the following may be the cause of the problem:
●One or both of the 12-
 volt battery terminals may be discon -
nected.
● The 12-
volt battery may be discharged.  (P. 5 3 6 )
Contact your Lexus dealer if the problem cannot be repaired, or if 
repair procedures are unknown. 
Page 532 of 608
532
5-2. Steps to take in an emergency
If you lose your keys
New genuine Lexus keys can be made by your Lexus dealer using the other 
keys and the key number stamped on your key number plate. 
Page 533 of 608
5
When trouble arises
533
5-2. Steps to take in an emergency
If the electronic key does not operate properly
Locking and unlocking the doors, unlocking the trunk and key linked functions
Doors
Use the mechanical key (P
 . 39) 
in order to perform the following 
oper
 ations (driver’s door only):
Locks all the doors
Closes the windows and moon 
roof (turn and hold)
*
Unlocks the door
Turning the key rearward unlocks 
the driver's door. Turning the key 
once again unlocks the other 
doors.
Opens the windows and moon 
roof (turn and hold)
*
*: This setting must be customized  at your Lexus dealer.
If communication between the electron ic key and vehicle is interrupted 
( 
P.  4 9 ) or the electronic key cannot be used because the battery is 
depleted, the smart access system with push-button start and wireless 
r
 emote control cannot be used. In such  cases, the doors and trunk can be 
opened and the hybrid system can be started by following the procedure 
below. 
Page 534 of 608
534
5-2. Steps to take in an emergency
Tr u n kTurn the mechanical key clock-
wise to open.
Changing “POWER” switch modes and starting the hybrid system
Depress the brake pedal.
Touch the Lexus emblem side of 
the electr
onic key to the 
“POWER” switch.
If any of the doors is opened or 
closed while the key is being 
touched to the switch, an alarm will 
sound to indicate that the start 
function cannot detect the elec -
tronic key. 
Page 535 of 608
5
When trouble arises
535
5-2. Steps to take in an emergency
To change “POWER” switch modes: Within 10 seconds of the 
buzzer sounding, release the brake pedal and press the 
“P
 OWER” switch. Modes can be changed each time the switch is 
pressed. ( P.  1 4 8 )
To start the hybrid system: Press the “POWER” switch within 10 
seconds of the buzz
 er sounding, keeping the brake pedal 
depressed.
In the event that the hybrid system  still cannot be oper
 ated, contact your 
Lexus dealer.
■Stopping the hybrid system
In the same method as the normal hybrid system stopping procedure, completely 
stop 
 the vehicle and then press the “POWER” switch.
■Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the elec -
tronic key battery be replaced immediately when the battery is depleted.  
(  P.  4 5 3 )
■When the electronic key does not work properly
Make sure that the smart access system wi th 
 push-button start has not been deacti-
vated in the customization setting. If it is off, turn the function on. 
(Customizable features  P.  5 7 2) 
Page 536 of 608
536
5-2. Steps to take in an emergency
If the vehicle 12-volt battery is discharged
The following procedures may be used to start the hybrid system if the vehi-
cle’s 12-volt battery is discharged. 
You can also call your Lexus dealer or a qualified repair shop.
If you have a set of jumper (or  booster) cables and a second vehicle 
with a 12-volt battery, you can jump start your vehicle by following the 
steps below.
Open the hood and fuse box 
co
ver.
Push the tab in and lift the lid off.
Open the exclusive jump start -
ing terminal cover.
Slightly pull the tab to open the 
cover. 
Page 537 of 608
5
When trouble arises
537
5-2. Steps to take in an emergency
Connect the jumper cables according to the following procedure:
Connect a positive jumper cable clamp to the exclusive jump start-
ing terminal on your vehicle
Connect the clamp on the other end  of the positiv
 e cable to the pos-
itive (+) battery terminal on the second v
 ehicle
Connect a negative cable clamp to the negative (-) battery terminal 
on the second vehicle
Connect the clamp at the other end of the negative cable to a solid, 
stationary, unpainted  metallic point aw
 ay from the exclusive jump 
starting terminal and any moving part s, as shown in the illustration.
Start the engine of the second  v
 ehicle. Increase the engine 
speed slightly and maintain that  le
 vel for approximately 5 min-
utes to recharge the 12-volt battery of your vehicle.
Maintain the engine sp eed of the second v
 ehicle and start the 
hybrid system of your vehicle by turning the “POWER” switch 
to ON mode.
Make sure the “READY” indicator  comes on. If the indicator 
does not come on, contact your Lexus dealer.
Once the hybrid system has star
 ted, remove the jumper cables 
in the exact reverse order from which they were connected. 
Page 538 of 608
538
5-2. Steps to take in an emergency
■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 3 4 )
●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 vehi cle cannot be towed without lifting both 
front wheels because the front wheels are locked by the parking lock.  
(  P.  4 8 3 )
●When the 12-volt battery is reconnected,  start the hybrid system, depress the 
brake pedal, and confirm that it is poss ible to shift into each shift position.
Close the exclusive jump starting terminal cover and reinstall 
the fuse box cover.
Once the hybrid system starts, have the vehicle inspected at your 
L
 exus dealer as soon as possible.  
Page 539 of 608
5
When trouble arises
539
5-2. Steps to take in an emergency
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 ju mper 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 comp ounds. 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 co me 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. 
Page 540 of 608
540
5-2. Steps to take in an emergency
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 ca nnot 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.