2010 Lexus HS250h heating

5
When trouble arises
541
5-2. Steps to take in an emergency
If your vehicle overheats
Correction procedures
■If the engine coolant temperature warning light comes on or flashes
Stop the vehicle in a safe place an d turn of
f the air conditioning
system.
Check to see if steam is coming out from the engine area.
If you see steam: 
Stop the hybrid system. Carefu lly lif
t the hood after the steam
subsides and then restart the hybrid system.
If you do not see steam:
Leave the hybrid system operating and carefully lift the hood.
Remove the engine compartment cover. ( P. 4 2 3 )
Check to see if the cooling fans are operating.
If the fans are operating: 
Wait until the high engine coolant temperature warning light goes
of
f and then stop the hybrid system.
If the fans are not operating: 
Stop the hybrid system immediately and call your Lexus dealer.
The following may indicate that your vehicle is overheating:
●The high engine coolant temperature warning light comes on or
flashes: 
The engine may be overheating.
● “HYBRID S
YSTEM OVERHEAT” is sh own on the multi-information
display: 
The power control unit may be overheating.
Follow the correction procedure as described below.

5
When trouble arises
543
5-2. Steps to take in an emergency
After the hybrid system has cooled
down, check the power control
unit coolant level and inspect the
cooling system for leaks.
Add power control unit coolant if
nec
essary.
Water can be used in an emer -
gency if power control unit coolant
is una
vailable. ( P. 5 5 2 )
Have the vehicle inspected at the ne arest Lexus dealer as soon as possi-
ble.
■Overheating
The following symptoms may occur wh en
your vehicle is overheating:
●The high engine coolant temperature warn ing light comes on or flashes, or the
hybrid system output decreases.
●Steam comes out from the engine area.
●“HYBRID SYSTEM OVERHEAT” is displayed on the multi-information display.

594
Alphabetical index
Child-protectors ......................................58
CleaningExterior ................................................... 402
Interior .....................................................406
Seat belts................................................ 407
Clock ......................................................... 373
Coin holder .............................................366
Compass ................................................... 391
Condenser ..............................................430
Console box ...........................................365
Cooling system Engine overheating ............................541
Cruise control Cruise control .......................................201
Dynamic radar cruise control .....205
Cup holders ............................................ 367
Curtain shield airbags.......................... 103
Customizable features ....................... 572
Daytime running light system ........... 186
Defogger Rear window ........................................260
Side mirrors ..........................................260
Dimensions............................................. 548
Dinghy towing ........................................248 Display
Dynamic radar cruise 
control ................................................. 205
Multi-information display ................ 169
Trip information.....................................172
Warning message ..............................501
Do-it-yourself maintenance ...............416
Door courtesy lights Door courtesy lights ........................ 360
Wattage ................................................. 556
Doors Door glasses........................................... 86
Door lock ................................ 44, 54, 57
Rear door child protector................ 58
Side doors................................................. 57
Side mirrors............................................. 83
Driver’s seat belt reminder light ..... 495
Driver’s seat position memory ........... 68
Driving Break-in tips........................................... 137
Correct posture.....................................101
Procedures............................................. 136
Winter driving tips .............................244
Driving position memory...................... 68
D

595
Alphabetical index
Electric power steering ......................225
Electronic keyIf the electronic key does not 
operate properly ............................ 533
Emergency, in case of If the electronic key does not 
operate properly ............................ 533
If the engine will not start ...............530
If the hybrid system will not 
start........................................................530
If the 12-volt battery is 
discharged ........................................ 536
If the warning buzzer sounds...... 492
If the warning light turns on .......... 492
If the warning message is 
displayed ............................................. 501
If you have a flat tire .......................... 521
If you lose your keys ........................ 532
If you think something is 
wrong................................................... 489
If your electronic key does 
not operate properly.................... 533
If your vehicle becomes stuck .... 545
If your vehicle needs to be  towed ................................................... 483
If your vehicle overheats.................. 541
Emergency flasher Switch ...................................................... 482 Engine
Accessory mode................................. 148
Compartment...................................... 422
Engine switch .........................................147
Hood ......................................................... 419
How to start the engine ....................147
How to start the hybrid 
system ....................................................147
Identification number ...................... 548
If the engine will not start............... 530
If the hybrid system will not 
start ....................................................... 530
Ignition switch ........................................147
Overheating .......................................... 541
Power switch..........................................147
Engine compartment cover ............. 423
Engine coolant Capacity .................................................552
Checking ...............................................428
Preparing and checking before winter .................................... 244
Engine/power control unit coolant Capacity .................................................552
Checking ...............................................428
Preparing and checking before winter .................................... 244
Engine immobilizer system.................. 96E

599
Alphabetical index
Outer foot lightsOuter foot lights................................. 360
Wattage ................................................. 556
Outside rear view mirrors Adjusting and folding ......................... 83
Driving position memory ................. 68
Mirror position memory ................... 68
Outside temperature display ............ 169
Overhead console .............................. 370
Overheating, Engine ............................ 541
Overheating, Hybrid system............. 541
Parking brake .......................................... 163
Parking lights Replacing light bulbs ....................... 469
Switch ........................................................183
Wattage ................................................. 556
PCS.............................................................232
Personal lights Personal lights ....................................... 361
Switch ........................................................ 361
Wattage ................................................. 556
Power outlet ............................................374
Power switch............................................ 147
Power windows........................................ 86
Pre-collision system .............................232 Radar cruise control ............................205
Radiator ....................................................430
Radio ......................................................... 265
Radio data system ................................ 267
RDS ............................................................ 267
Rear side marker lights
Replacing light bulbs ........................ 479
Wattage ................................................. 556
Rear sunshade ....................................... 378
Rear turn signal lights Replacing light bulbs ........................470
Wattage ................................................. 556
Rear view mirror Compass................................................. 391
Rear window defogger ......................260
Replacing Electronic key battery ......................453
Fuses........................................................ 455
Light bulbs ............................................ 469
Tires ........................................................... 521
Reporting safety defects for 
U.S. owners ......................................... 586
Safety connect .......................................395
Scuff lighting ...........................................360
P
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