Page 509 of 600
509
GS F_OM_OM30G90U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge (P. 86, 92) enters the
red zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display.
●Steam is coming from under the hood.
Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down sufficiently, inspect the hoses and cooling
core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2
Page 511 of 600
5117-2. Steps to take in an emergency
GS F_OM_OM30G90U_(U)
7
When trouble arises
Add coolant if necessary.
Water can be used in an emerge ncy if coolant is unavailable.
Start the engine and turn the air conditio ning system on to check that the radi-
ator cooling fans operate and to check for coolant leaks from the radiator or
hoses.
The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are operating by checking the fan sound and air flow.
If it is difficult to check these, turn the air conditioning system on and off repeatedly.
(The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately an d contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
5
GS350GS F
GS300
6
7
Page 513 of 600

5137-2. Steps to take in an emergency
GS F_OM_OM30G90U_(U)
7
When trouble arises
WARNING
■When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
●If steam is seen coming from under the h ood, do not open the hood until the steam
has subsided. The engine compartment may be very hot.
●Keep hands and clothing (especially a tie, a scarf or a muffler) away from the fans and
belts. Failure to do so may cause the hands or clothing to be caught, resulting in seri-
ous injury.
●GS350: Do not loosen the coolant inlet cap
or the engine coolant reservoir cap while the
engine and radiator are hot.
High temperature steam or coolant could
spray out.
●GS F: Do not loosen the engine coolant res-
ervoir cap while the engine and radiator are
hot.
High temperature steam or coolant could
spray out.
●GS300: Do not loosen the coolant inlet cap,
the engine coolant rese rvoir cap or the inter-
cooler coolant reservoir cap while the engine
and radiator are hot.
High temperature steam or coolant could
spray out.
Page 591 of 600

591Alphabetical index
GS F_OM_OM30G90U_(U)
Radar cruise control (dynamic radar cruise control with
full-speed range) ............................... 259
Radiator ....................................................388
Radio
*
RBDS (Radio Broadcast Data Systems)
*
Rear air conditioning system .............321
Rear door sunshades ............................341
Rear personal lights............................. 330
Rear side marker lights ........................216 Light switch ............................................ 216
Replacing light bulbs ........................420
Welcome light illumination control ......................... 138
Rear seat heaters.................................. 325
Rear sunshade .........................................341 Operation ............................................... 341
Reverse operation feature............. 342 Rear turn signal lights ........................... 210
Replacing light bulbs ....................... 420
Turn signal lever ...................................210
Rear view mirror Inside rear view mirror......................169
Outside rear view mirrors ................ 171
Rear view monitor system
*
Rear window defoggers ...................... 316
Refueling.................................................. 228 Capacity................................................... 521
Fuel types................................................. 521
Opening the fuel tank cap ............ 229
When the fuel filler door cannot be opened ......................... 230
Remote Touch
*.................................... 304
Replacing Electronic key battery .......................410
Fuses .......................................................... 412
Light bulbs...............................................418
Tires ...........................................................472
Rev indicator .....................................88, 95
Rev peak ............................................. 88, 96
Reporting safety defects for U.S. owners .................................. 562
Resetting the message indicating maintenance is required ................ 366
R
*: Refer to the “NAVIGATION AND MULTIMEDIA SYSTEM OWNER’S MANUAL”.