2008 Lexus GS450h air conditioning

453
4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
■Checking interval
Inspect and replace the air conditioning filter according to the maintenance sched-
ule. In dusty areas or areas with heavy traffic flow, early replacement may be
required. (For scheduled maintenance information, refer to the “Warranty and Ser-
vices Guide/Owner’s Manual Supplement/Scheduled Maintenance”.)
■If air flow from the vents decreases dramatically
The filter may be clogged. Check the filter and replace if necessary.
NOTICE
■To prevent damage to the system
●When using the air conditioning system, make sure that a filter is always installed.
●When cleaning the filter, do not clean the filter with water.

462
4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
FuseAmpereCircuit
23A/F15Fuel system
24INV W/P10Hybrid system
25IGCT No.120Hybrid system, IGCT No.2, 
IGCT No.3
26FR FOG15Fog light
27FR TAIL10Tail light, rear side marker light
28WA S H20Windshield wipers and washer
29HORN10Horn
30H-LP UPR20Headlight high beam
31DC/DC140Charging system
32RAD FAN60Electric cooling fans
33LH J/B AM80
S/ROOF, FR P/SEAT LH, TV, A/C,
FUEL OPN, FR WIP, H-LP LVL, 
FR S/HTR LH, A/C W/P
34E/G AM60H-LP CLN, FR CTRL-AM, DEICER,
STB AM
35HEATER50Air conditioning system
36DEFOG50Rear window defogger
37ABS230VSC, ABS
38RH J/B-AM80
AM1, OBD, STOP SW, TI & TE, 
FR P/SEAT RH, STR LOCK, 
SECURITY, ECU-IG R, RH-IG, 
F S/HTR RH, CIG, PWR OUTLET, 
AIR SUS

464
4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
■Left side instrument panel
FuseAmpereCircuit
1FR WIP30Windshield wipers and washers
2RR-IG7. 5RR-IG1
3LH-IG10
Emergency flashers, seat belt preten-
sioners, headlight cleaners, exhaust
system, rear window defogger, elec-
tric cooling fans, front left door con-
trol system, rear left door control
system
4H-LP LVL7. 5Adaptive front lighting system
5A/C W/P7. 5Air conditioning system
6RAD No.310Audio system
7FR DOOR LH20Front left door control system
8RR DOOR LH20Rear left door control system
9FR S/HTR LH15Seat heaters, seat heaters and venti-
lators

465
4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
FuseAmpereCircuit
10ECU-IG LH10
VGRS, EPS, electronically con-
trolled brake system, yaw rate & G
sensor, dynamic radar cruise control
system, rear view monitor system,
moon roof
11PA N E L7. 5
Steering switches, distance control
switch, audio system, glove box light,
switch illumination, cigarette lighter,
shift lever light, touch screen, rear
personal lights
12S/ROOF25Moon roof
13FUEL OPEN10Fuel lid opener
14LH-B10Theft deterrent system
15TRK OPN10Trunk opener
16TV7. 5Touch screen, rear view monitor sys-
tem
17A/C7. 5Air conditioning system
18FR P/SEAT LH30Po w e r s e a t

466
4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
■Right side instrument panel
FuseAmpereCircuit
1ECU-IG RH10
Electric tilt and telescopic steering,
combination switch, power seat,
smart access system with push-but-
ton start, air conditioning system,
touch screen, shift lock system, tire
pressure warning system, front/rear
stabilizer system
2FR S/HTR RH15Seat heaters, seat heaters and venti-
lators
3RH-IG7. 5
Front right door control system, rear
right door control system, seat belt
pretensioners, transmission, seat
heaters, seat heaters and ventilators
4AM27. 5Starting system
5FR DOOR RH20Front right door control system
6RR DOOR RH20Rear right door control system

488
5-1. Essential information
GS_HV_U
December 12, 2007 3:50 pm
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■ Visible symptoms
●Fluid leaks under the vehicle 
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temper ature gauge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
■ Operational symptoms
●Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor

538
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
If your vehicle overheats
If your hybrid system overheats:
Stop the vehicle in a safe place and turn off the air conditioning
system.
Check to see if steam is coming out from under the hood.
If you see steam: 
Stop the hybrid system and carefully lift the hood.
If you do not see steam: Leave the hybrid system running and carefully lift the hood.
Remove the engine compartment cover. ( P. 421)
Check to see if the cooling fan is operating.
If the fan is operating: 
Wait until the engine coolant temperature gauge begins to
fall and then stop the hybrid system.
If the fan is not operating: 
Stop the hybrid system immed iately and call your local
Lexus dealer.
After the hybrid system has
cooled down sufficiently, check
the coolant level and inspect the
radiator core (radiator) for any
leaks.STEP1
STEP2
STEP3
STEP4
STEP5

563
6-1. Specifications
6
Vehicle specifications
GS_HV_U
December 12, 2007 3:50 pm
Tire related termMeaning
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of transmission, power
steering, power brakes, power windows, power seats,
radio and heater, to the extent that these items are
available as factory-installed equipment (whether
installed or not)
Curb weight
The weight of a motor vehicle with standard equip-
ment, including the maximum capacity of fuel, oil and
coolant, and if so equipped, air conditioning and
additional weight optional engine
Maximum loaded vehicle
weight
The sum of: 
(a) Curb weight 
(b) Accessory weight 
(c) Vehicle capacity weight 
(d) Production options weight
Normal occupant weight150 lb. (68 kg) times the number of occupants speci-
fied in the second column of Table 1* that follows
Occupant distributionDistribution of occupants in a vehicle as specified in
the third column of Table 1* below
Production options
weight
The combined weight of installed regular production
options weighing over 5 lb. (2.3 kg) in excess of the
standard items which they replace, not previously
considered in curb weight or accessory weight,
including heavy duty brakes, ride levelers, roof rack,
heavy duty battery, and special trim
RimA metal support for a tire or a tire and tube assembly
upon which the tire beads are seated
Rim diameter 
(Wheel diameter)Nominal diameter of the bead seat