2008 Lexus GS450h brake

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

467
4-3. Do-it-yourself maintenance
4
Maintenance and care
GS_HV_U
December 27, 2007 1:38 pm
FuseAmpereCircuit
7AIR SUS20AV S
8PWR OUTLET15Po w e r o u t l e t
9CIG15Cigarette lighter
10ACC7. 5
Audio system, smart access system
with push-button start, touch screen,
rear view monitor system, Lexus Link
System ECU
11IGN10
Smart access system with push-but-
ton start, SRS airbag system, stop-
lights, hybrid system, steering lock
system, electronically controlled
brake system, Lexus Link System
ECU, front passenger occupant clas-
sification system ECU
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

482
GS_HV_U
December 12, 2007 3:50 pm
5-1. Essential information
If your vehicle needs to be towed
Before towingThe following may indicate a problem with your transmission. Contact
your Lexus dealer before towing.
● The hybrid system is running, but the vehicle will not move.
● The vehicle 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 secured to the emergency towing
eyelet. This should only attempted on hard, surfaced roads for short dis-
tances below 18 mph (30 km/h). 
A driver must be in the vehicle to s teer and operate the brakes. The vehi-
cle’s wheels, drive train, axles, steering and brakes 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 , and abide by all state/provincial
and local laws.
If towing from the rear, 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
483
5-1. Essential information
GS_HV_U
December 12, 2007 3:50 pm
Towing eyelet
■Emergency towing procedureRelease the parking brake.
Put the shift lever in “N”.
The “POWER” switch must be in the ACCESSORY mode (hybrid system
off) or the ON mode (hybrid system on).
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

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

5
When trouble arises
489
5-1. Essential information
GS_HV_U
December 12, 2007 3:50 pm
Event data recorder
In a crash or a near car crash eventThe SRS airbag sensor ass embly contains the EDR. In a crash or a near
car crash event, this devic e may record some or all of the following infor-
mation:
● Gasoline engine speed
● Whether the brake pedal was applied or not
● Vehicle speed
● To what extent the accelerator pedal was depressed
● Position of the transmission shift lever
● Whether the driver and front passenger wore seat belts or not
● Driver’s seat position
● SRS airbag deployment data
● SRS airbag system diagnostic data
● Front passenger’s occupant classification
Your vehicle has computers that monitor and control certain aspects of
your vehicle. These computers assist in driving and maintaining optimal
vehicle performance.
Besides storing data useful for troublesh ooting, there is a system to record
data in a crash or a near car crash event. This is called an Event Data
Recorder (EDR).

5
When trouble arises
491
GS_HV_U
December 12, 2007 3:50 pm
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 in dicates a possible problem in the brake system.
Immediately stop the vehicl e in a safe place and contact your Lexus
dealer.
*1: Parking brake engaged warning buzzer:
 P. 5 0 6
Stop the vehicle immediately.
The following warning indicates the po ssibility of damage to the vehicle
that may lead to an ac cident. Immediately stop the vehicle in a safe place
and contact your Lexus dealer.
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Brake system warning light (warning buzzer) *1
•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.
Warning lightWarning light/Details
Charging system warning lightMalfunction in the vehicle’s charging system.
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.

492
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
Have the vehicle inspected immediately.Failing to investigate the cause of the following warnings may lead to the
system operating abnormally and possibly cause an accident. Have the
vehicle inspected by your Lexus dealer immediately.
*2: Electronically Controlled Brake System
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Malfunction indicator lamp
Malfunction in:
• The electronic engine control system;
• The hybrid system;
• The electronic throttle control system; or
• The transmission control system.
SRS warning lightMalfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system.
(U.S.A.)

(Canada)
ABS warning lightMalfunction in:
•The ABS; or
• The brake assist system.
ECB*2/VSC warning light
Malfunction in:
• The electronically controlled brake system; or
• The VSC.
Electric power steering system warning light Malfunction in the EPS.
“PCS” warning light (if equipped)Malfunction in the pre-collision system.