brake Lexus GS450h 2007 Using the hands-free system (for cellular phone) / LEXUS 2007 GS450H THROUGH JUNE 2006 PROD. (OM30727U) Service Manual

403
4-3. Do-it-yourself maintenance
4
Maintenance and care
FuseAmpereCircuit
39RR J/B80STOP LP R, STOP LP L, RR TAIL,
PSB, RR FOG, RR-IG1
40OIL PUMP60Tr a n s m i s s i o n
41EPS80EPS
42P/ I - B 160EFI, F/PMP, INJ
43E/G-B30EM-VLV, FR CTRL-B, ETCS
44MAIN30H-LP R LWR, H-LP L LWR
45VGRS40VGRS
46ABS150ABS MOTOR, ABS MAIN1, 
ABS MAIN2
47P/ I - B 260A/F, BATT FAN, IGCT, INV W/P
48BATT FAN20Electric cooling fans
49RAD No.130Audio system
50RAD No.230Audio system
51IG2 MAIN20IG2, GAUGE, IGN
52TURN-HAZ15Front turn signal lights, rear turn 
signal lights
53ABS MAIN310Electronically controlled brake sys-
tem
54ECU-B10VGRS, EPS

404
4-3. Do-it-yourself maintenance
■Driver’s side instrument panel
FuseAmpereCircuit
1FR WIP30Windshield wipers
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
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

407
4-3. Do-it-yourself maintenance
4
Maintenance and care
FuseAmpereCircuit
10ACC7. 5
Audio system, smart access system
with push-button start, touch screen,
rear view monitor system
11IGN10
Smart access system with push-but-
ton start, SRS airbag system, stop-
lights, hybrid system, steering lock
system, electronically controlled
brake system
12GAUGE7. 5Gauges and meters
13STR LOCK25Steering lock system
14SECURITY7. 5Smart access system with push-but-
ton start
15TI & TE20Electric tilt and telescopic steering
16AM17. 5
17STOP SW7. 5Stoplights, shift lock system
18OBD7. 5On-board diagnosis system
19FR P/SEAT RH30Po w e r s e a t

420
5-1. Essential information
If your vehicle needs to be towed
Before towing
The following may indicate a problem with your transmission. Contact
your Lexus dealer before towing.
● The hybrid s
ystem is running, but the vehicle will not move.
● The v
ehicle makes an abnormal sound.
Emergency towing
If a tow truck is not available, in an emergency your vehicle may be tem-
porarily towed using a cable or ch ain secur
ed to the emergency towing
eyelet. This should only attempted on hard, surfaced roads for short dis-
tances at low speeds. 
A driver must be in the vehicle to steer and oper
ate the brakes. The vehi-
cle’s wheels, drive train, axles, steering and br
akes must be in good condi -
tion.
If towing is necessary, we recommen d having your vehicle towed by your
Lexus dealer or a commercial towing service, using a lift-type truck or a flat
bed truck.

Use a safety chain system for all towing , a
nd abide by all state/provincial
and local laws.
The wheels and axle on the ground must be in good condition.
If they are damaged, use a to wing dolly
or flat bed truck.

5
When trouble arises
421
5-1. Essential information
Towing eyelet
■Emergency towing procedureRelease the parking brake.
Put the shift lever in “N”.
The power switch must be in the “ACC” mode (hybrid system off) or the
“IG-ON” mode (hybrid system on).
CAUTION
■Caution while towing
●Use extreme caution when towing the vehicle. 
Avoid sudden starts or erratic driving maneuvers which place excessive stress on
the emergency towing eyelet and the cable or chain.
●If the hybrid system is not running, the power assist for the brakes and steering
will not function, making steeri ng and braking more difficult.
NOTICE
■To prevent causing serious damage to the transmission
Never tow this vehicle from the front with the rear wheels on the ground. 
This may cause serious dama ge to the transmission.
STEP1
STEP2
STEP3

5
When trouble arises
427
5-1. Essential information
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 v
ehicle
(Water dripping from the air conditioning after use is normal.)
● Flat
-looking tires or uneven tire wear
●Engine coolant temper atur
e gauge needle continually points
higher than normal
■ A
udible symptoms
●Changes in e
xhaust sound
● Ex
cessive tire squeal when cornering
●Str
ange noises related to the suspension system
●P
inging or other noises related to the hybrid system
■ Oper
ational symptoms
●Engine mis
sing, stumbling or running rough
●A
ppreciable loss of power
●V
ehicle pulls heavily to one side when braking
●V
ehicle pulls heavily to one side when driving on a level road
● L
oss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor

5
When trouble arises
429
5-1. Essential information
●To what extent the accelerator pedal was depressed
● T
o what extent the brake pedal was applied
●T
o what extent the ECU controlled the condition of the 4 wheels
● V
ehicle stability control system diagnostic data
The information above is intended to be used for the purpose of impr
ov-
ing vehicle safety performance. Unlik
e general data recorders, the EDR
does not record sound data such as conversation between passengers.
Disclosure of the data
Lexus will not disclose the data recorded in an EDR to a third party
except when:
●An agr
eement from the vehicle's ow ner (or the leasing company for a
leased vehicle) is obtained
● Of
ficially requested by the police or other authorities
●Used as a defense for L
exus in a law suit
● Or
dered by a court
However, if necessary Lexus will:
●Use the data for r
esearch on Lexus vehicle safety performance
● Disclose the data to a thir
d party for research purposes without dis -
closing details of the vehicle owner, and only when it is deemed neces -
sary
● Disclose summariz
ed data cleared of vehicle id entification information
to a non-Lexus organization for research purposes

430
5-2. Steps to take in an emergency
If a warning light turns on or a warning buzzer sounds...
Stop the vehicle immediately. Continuing to drive the vehicle may be dangerous.
The following warning indicates a possible problem in the brake system.
Immediately stop the vehicl e in a safe place and contact your Lexus
dealer.
*: Parking brake engaged warning buzzer:
 P. 4 4 4
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Brake system warning light (warning buzzer)*
•Low brake fluid
• Malfunction in the brake system
This light also comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released, the system is operating normally.
Calmly perform the following actions if any of the warning lights turn on or
flash. If a light turns on or flashes, bu t then turns off, this does not necessar
-
ily indicate a malfunction in the system.

432
5-2. Steps to take in an emergency
*1: Electronically Controlled Brake System
Have the malfunction repaired immediately.
After taking the specified steps to correct the suspected problem, check
that the warning light turns off.
Warning lightWarning light/Details
(U.S.A.)

(Canada)
ABS warning lightMalfunction in:
•The ABS; or
• The brake assist system.
ECB*1/VSC warning light
Malfunction in:
• The electronically controlled brake system; or
• The VSC.
Electric power steering system warning light Malfunction in the EPS.
Pre-collision system warning light (if equipped)Malfunction in the pre-collision system.
Warning lightWarning light/DetailsCorrection procedure
Open door warning light 
(warning buzzer)
*2
A door or a trunk is not fully
closed.
Check that all doors and the
trunk are closed.
Low fuel level warning light Remaining fuel 
(Approximately 2.6 gal. [10
L, 2.2 Imp.gal.] or less)
Refuel the vehicle.

5
When trouble arises
435
5-2. Steps to take in an emergency
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pr
essure warning reset switch does not turn off the tire pressure warning light.
■The tire pressure warning light may turn on due to natural causes
The tire pressure warning light may turn on due to natural causes such as natural air
le
aks or tire inflation pressure changes caused by temperature. In this case, adjust -
ing the tire inflation pressure will turn off the warning light.
CAUTION
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause loss of
vehicle control and result in death or serious injury.
●Vehicles with run-flat tires:
• Decelerate to the lowest appropriate speed as soon as possible. Do not drive
over 55 mph (90 km/h).
• Check and adjust the tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure
adjustment, it is probable that you have a flat tire. Have the tire replaced by
the nearest Lexus dealer.
• Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
●Vehicles with standard tires:
• Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure adjustment, it is probable that you have a flat tire. Check the tires. If the tire is
flat, change to the spare tire and have the flat tire repaired by the nearest
Lexus dealer.
• Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.