Page 75 of 860

751-2. Hybrid system
GS450h_U (OM30D01U)
1
For safety and security
There are air intake vents on the
both sides of the rear seatback for
the purpose of cooling the hybrid
battery (traction battery). If the
vents become blocked, the hybrid
battery may overheat, leading to a
reduction in hybrid battery output.
When a certain level of impact is detected by the impact sensor, the emer-
gency shut off system blocks off the high voltage current and stops the fuel
pump to minimize the risk of electr ocution and fuel leakage. If the emer-
gency shut off system activates, your ve hicle will not restart. To restart the
hybrid system, contact your Lexus dealer.
A message is automatically displayed when a malfunction occurs in the
hybrid system or an improper operation is attempted.
If a warning message is shown on
the multi-information display, read
the message and follow the instruc-
tions.
( P. 721)
Hybrid battery (traction battery) air vents
Emergency shut off system
Hybrid warning message
Page 675 of 860
GS450h_U (OM30D01U)
6756-3. Do-it-yourself maintenance
6
Maintenance and care
11ABS MAIN 210Brake system
12ABS MAIN 110Brake system
13IGCT NO.130IGCT NO.2, IGCT NO.3, IGCT NO.4,
IGCT NO.5
14ECU-B7. 5Smart access system with push-button start
15INV W/P10Hybrid system
16ETCS10Multiport fuel injection system/sequential
multiport fuel injection system
17EPS-B10Electric power steering system
18D/C CUT30DOME, MPX-B
19HORN10Horn
20ODS5Occupant classification system
21TV7. 5Remote Touch screen
22P/ I - B N O. 280IG2 MAIN, EFI MAIN, EDU, F/PMP, A/F
23ABS NO.230ECB
24P/ I - B N O.150H-LP HI RH, H-LP HI LH, DRL
25H-LP LO30H-LP LO RH, H-LP LO LH
26LH J/B-B40Left-hand junction block
27RH J/B-B40Right-hand junction block
28VGRS40No circuit
29OIL PMP60Oil pump
30IGCT NO.57. 5Power management system, shift position
sensor
31WIP-S7. 5Windshield wipers, driver support system
32WA S H - S5Windshield washer, driver support system
33COMB SW5Windshield wipers
FuseAmpereCircuit
Page 792 of 860

792
GS450h_U (OM30D01U)
8-1. Specifications
Fuel information
■Fuel tank opening for unleaded gasoline
To help prevent incorrect fueling, your vehicle has a fuel tank opening that only
accommodates the special nozzle on unleaded fuel pumps.
■Gasoline quality
In very few cases, driveability problems ma y be caused by the brand of gasoline you
are using. If driveability problems persist, try changing the brand of gasoline. If this
does not correct the problem, consult your Lexus dealer.
■Gasoline quality standards
●Automotive manufacturers in the U.S.A., Europe and Japan have developed a
specification for fuel quality called the World-Wide Fuel Charter (WWFC), which
is expected to be applied worldwide.
●The WWFC consists of four categories that are based on required emission levels.
In the U.S., category 4 has been adopted.
●The WWFC improves air quality by lowering emissions in vehicle fleets, and
improves customer satisfaction through better performance.
You must only use unleaded gasoline in your vehicle.
Select premium unleaded gasoline with an octane rating of 91
(Research Octane Number 96) or higher required for optimum engine
performance. If 91 octane cannot be obtained, you may use unleaded
gasoline with an octane rating as low as 87 (Research Octane Number
91). Use of unleaded gasoline with an octane rating lower than 91 may
result in engine knocking and signif icantly reduced performance. Per-
sistent knocking can lead to engine damage and should be corrected
by refueling with higher octane unleaded gasoline.
At minimum, the gasoline you us e should meet the specifications of
ASTM D4814 in the U.S.A. and CGSB3.5-M93 in Canada.
Page 793 of 860

GS450h_U (OM30D01U)
7938-1. Specifications
8
Vehicle specifications
■Recommendation of the use of gasoline containing detergent additives
●Lexus recommends the use of gasoline that contains detergent additives to avoid
the build-up of engine deposits.
●All gasoline sold in the U.S.A. contains detergent additives to clean and/or keep
clean intake systems.
■Recommendation of the use of cleaner burning gasoline
Cleaner burning gasoline, including reformul ated gasoline that contains oxygenates
such as ethanol or MTBE (Methyl Tertiary Butyl Ether) is available in many areas.
Lexus recommends the use of cleaner burn ing gasoline and appropriately blended
reformulated gasoline. These types of ga soline provide excellent vehicle perfor-
mance, reduce vehicle emissions and improve air quality.
■Non-recommendation of the use of blended gasoline
●If you use gasohol in your vehicle, be sure that it has an octane rating no lower than
87.
●Lexus does not recommend the use of gasoline containing methanol.
■Non-recommendation of the use of gasoline containing MMT
Some gasoline contains an octane enhanc ing additive called MMT (Methylcyclo-
pentadienyl Manganese Tricarbonyl).
Lexus does not recommend the use of gasoli ne that contains MMT. If fuel containing
MMT is used, your emission control system may be adversely affected.
The malfunction indicator lamp on the instrument cluster may come on. If this hap-
pens, contact your Lexus dealer for service.
■If your engine knocks
●Consult your Lexus dealer.
●You may occasionally notice light knocking for a short time while accelerating or
driving uphill. This is normal and there is no need for concern.
●Use only gasoline containing a maximum of
10% ethanol.
DO NOT use any flex-fuel or gasoline that
could contain more than 10% ethanol,
including from any pump labeled E15, E30,
E50, E85 (which are only some examples
of fuel containing mo re than 10% ethanol).DO NOT use gasoline con-
taining more than 10% ethanol.
(15% ethanol)
(50% ethanol)
(85% ethanol)