cooling Lexus GS250 2012 Owner's Manual

3324-5. Using the driving support
GS350/250_EE (OM30C36E)
Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the
air conditioning system to enhance fuel efficiency (P. 409). To improve air
conditioning performance, adjust the fan speed or turn off Eco drive mode.
Automatic operation of the seat heater during Eco drive mode
If the driving mode select switch is switched to Eco drive mode in cold tem-
peratures, the seat heater will be automatically operated to assist heating per-
formance.
Sport mode automatic deactivation
Sport mode is automatically deactivated if the engine switch is turned off
after driving in sport mode.

4125-2. Using the air conditioning system and defogger
GS350/250_EE (OM30C36E)Fan speed control
Air flows to the feet and the
windshield defogger operates
Outside temperature
Right-hand front seat side
temperature control
Right-hand front seat side
temperature display
Front seat air outlet selector
“nanoe” system (if
equipped)
Pollen removal mode
DUAL/3-ZONE mode
Cooling and dehumidifica-
tion function on/off
Left-hand front seat side tem-
perature displayLeft-hand front seat side tem-
perature control
Windshield defogger
Outside air or recirculated
mode
Air outlet selector
S-FLOW mode
Off
Automatic mode
Left-hand front seat side air
outlet selector
Rear air conditioning opera-
tion screen
Right-hand front seat side air
outlet selector
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4215-2. Using the air conditioning system and defogger
5
Interior features
GS350/250_EE (OM30C36E)
Using automatic mode
Fan speed is adjusted automatically according to the temperature setting and
the ambient conditions.
Therefore, the fan may stop for a while until warm or cool air is ready to flow
immediately after is pressed.
Humidity sensor
Fogging up of the windows
The windows will easily fog up when the humidity in the vehicle is high.
Selecting on will dehumidify the air from the outlets and defog the
windshield effectively.
If you off, the windows may fog up more easily.
The windows may fog up if the recirculated air mode is used.
Outside/recirculated air mode
When driving on dusty roads such as tunnels or in heavy traffic, set the out-
side/recirculated air mode button to the recirculated air mode. This is effec-
tive in preventing outside air from entering the vehicle interior. During
cooling operation, setting the recirculated air mode will also cool the vehi-
cle interior effectively.
Outside/recirculated air mode may automatically switch depending on the
temperature setting or the inside temperature. A sensor, which detects humidity inside
the vehicle and the temperature of the
windshield, is provided to detect fog on
the front windscreen. Due to the sensor,
when automatic mode is set the air condi-
tioning may make the following controls:
Changing the amount of air flow
Changing the amount of air introduced
from outside when in outside air mode
with the air vents in the position
Changing the settings of the air vents to
when the is set

6566-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
CAUTION
When working near the electric cooling fans or radiator grille
Be sure the engine switch is off.
With the engine switch in IGNITION ON mode, the electric cooling fans
may automatically start to run if the air conditioning is on and/or the cool-
ant temperature is high. (P. 667)
Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc.
from getting in your eyes.
NOTICE
If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine
wear due to dirt in the air. Also, a backfire could cause a fire in the engine
compartment.
If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads
wear or when the fluid level in the accumulator is high.
If the reservoir needs frequent refilling, it may indicate a serious problem.

6606-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
Engine compartment
For right-hand drive vehicles:
The battery and the fuse box in front of the battery are located on the oppo-
site side of the engine compartment.
Fuse boxes (P. 700)
Battery (P. 667)
Engine oil level dipstick
(P. 662)
Engine coolant reservoir
(P. 665)Engine oil filler cap
(P. 663)
Washer fluid tank (P. 671)
Electric cooling fans
Condenser (P. 667)
Radiator (P. 667)1
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665 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS350/250_EE (OM30C36E)The coolant level is satisfactory if it is between the “FULL” and
“LOW” lines on the reservoir when the engine is cold.
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. (P. 829)
Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality eth-
ylene glycol based non-silicate, non-amine, non-nitrite, and non-borate cool-
ant with long-life hybrid organic acid technology.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50%
deionized water. (Minimum temperature: -35C [-31F])
For more details about engine coolant, contact any authorized Lexus dealer
or repairer, or another duly qualified and equipped professional.
If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine coolant reservoir caps, drain cock
and water pump.
If you cannot find a leak, have any authorized Lexus dealer or repairer, or
other duly qualified and equipped professional, test the cap and check for
leaks in the cooling system.
Engine coolant
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6666-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
CAUTION
When the engine is hot
Do not remove the engine coolant reservoir cap or the radiator cap. (P.
830)
The cooling system may be under pressure and may spray hot coolant if the
cap is removed, causing serious injuries, such as burns.
NOTICE
When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of
water and antifreeze must be used to provide proper lubrication, corrosion
protection and cooling. Be sure to read the antifreeze or coolant label.
If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.

707 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS350/250_EE (OM30C36E)
24ETCS10Multiport fuel injection system/sequen-
tial multiport fuel injection system
25HORN10Horn
26R/B-B20EPS-B, TV
27P/I-B NO.150Headlights, daytime running lights, EBS
28EPB30Parking brake
29LUG J/B-B40Luggage compartment junction block
30FAN NO.180Electric cooling fans
31LH J/B ALT60Left-hand junction block
32H-LP CLN30Headlight cleaner
33FAN NO.240Electric cooling fans
34A/C COMP7.5Air conditioning system
35FILTER10Condenser
FuseAmpereCircuit

709 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS350/250_EE (OM30C36E)
16MPX-B10
Smart entry & start system, electric tilt
and telescopic steering column, power
seats, head-up display, front right-hand
door ECU, gauges and meters, steering
sensor, yaw rate and G sensor, overhead
module, front left-hand door ECU,
power trunk lid, clock, body ECU, RR
CTRL SW, CAN gateway ECU
17FILTER10Condenser
18A/C COMP7.5Air conditioning system
19H-LP CLN30Headlight cleaner
20FAN NO.240Electric cooling fans
21LH J/B ALT60Left-hand junction block
22FAN NO.180Electric cooling fans
23P/I-B NO.150H-LP HI RH, H-LP HI LH, DRL, emer-
gency brake signal
24EPB30Parking brake
25LUG J/B-B40Luggage compartment junction block
26R/B-B20EPS-B, TV
27HORN10Horn
28ETCS10Multiport fuel injection system/sequen-
tial multiport fuel injection system
29ALT-S7.5Charging system
30ECU-B7.5Smart entry & start system
31DCM7.5DCM
32D/C CUT30DOME, MPX-B
33ABS NO.250VDIM
34ST30Starting system
35H-LP LO30Headlights, H-LP RLY
FuseAmpereCircuit

829
7 7-2. Steps to take in an emergency
When trouble arises
GS350/250_EE (OM30C36E)
NOTICE
When handling jumper cables
When connecting the jumper cables, ensure that they do not become entan-
gled in the cooling fans or engine drive belt.