2010 Lexus GS450h transmission

506
4-3. Do-it-yourself maintenance
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
■Right side instrument panel
FuseAmpereCircuit
1ECU-IG RH10
Tilt and telescopic steering, combina-
tion switch, power seat, smart access
system with push-button start, air
conditioning system, touch screen,
shift lock system, tire pressure warn-
ing system, front/rear stabilizer sys-
tem
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

5
When trouble arises
523
5-1. Essential information
GS_HV_U (OM30C81U)
January 28, 2010 10:42 am
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 system is operating, but the vehicle will not move.
●The vehicle makes an abnormal sound.
If towing is necessary, we recommend 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 towing dolly or flat bed truck.

5
When trouble arises
525
5-1. Essential information
GS_HV_U (OM30C81U)
January 28, 2010 10:42 am
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. Always use caution for the
surroundings and other vehicles while towing.
●If the hybrid system is off, the power assist for the brakes and steering will not
function, making steering 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 damage to the transmission.

5
When trouble arises
529
5-1. Essential information
GS_HV_U (OM30C81U)
January 28, 2010 10:42 am
Towing with a wheel lift-type truck
From front
Use a towing dolly under the rear
wheels.
From rear
Turn the “POWER” switch to the
ACCESSORY mode so that the
steering wheel is unlocked.
NOTICE
■To prevent causing serious damage to the transmission
Never tow this vehicle from the front with the rear wheels on the ground.
■To prevent damaging the vehicle
●Do not tow the vehicle with the “POWER” switch is OFF. 
The steering lock mechanism is not strong enough to hold the front wheel
straight.
●When raising the vehicle, ensure adequate ground clearance for towing at the
opposite end of the raised vehicle. Without adequate clearance, the vehicle
could be damaged while being towed.

532
5-1. Essential information
GS_HV_U (OM30C81U)
January 28, 2010 10:42 am
Event data recorder
In a crash or a near car crash event
The SRS airbag sensor assembly contains the EDR. In a crash or a near
car crash event, this device 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 troubleshooting, 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
535
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
Have the vehicle inspected immediately.
Failure 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.
Warning lightWarning light/Details
(U.S.A.)
(Canada)
Malfunction indicator lamp
Malfunction in:
• The emission control system;
• The electronic engine control system;
• The hybrid system;
• The electronic throttle control system; or
• The transmission control system.
SRS warning light
Malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system.
(U.S.A.)
(Canada)
ABS warning light
Malfunction in:
•The ABS; or
• The brake assist system.
ECB (Electronically controlled brake system) warning light
Malfunction in the electronically controlled brake system.
Electric power steering system warning light
Malfunction in the EPS.
“PCS” warning light (if equipped)
Malfunction in the pre-collision system.

5
When trouble arises
551
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
Wa r n i n g m e s s a g eDetailsCorrection procedure
(Flashing)
(If equipped)
The radar cruise control
system is unable to judge
vehicle-to-vehicle dis-
tance.
• Turn the mode select
switch to either the nor-
mal or power mode.
• If the windshield wipers
are on, turn them off or
set them to either the
intermittent or the slow
mode.
(If equipped, flashing)
Yo u r v e h i c l e i s n e a r i n g
the vehicle ahead (in
radar cruise mode).Slow the vehicle by apply-
ing the brakes.
The hybrid system has
overheated.Stop and check. 
(P. 5 8 1 )
(Flashing)
(If equipped)
Alerts the driver that
there is a high possibility
of collision or the pre-col-
lision braking has acti-
vated.
Depress the brake pedal.
The vehicle is unable to
drive over 60 mph until
the transmission warms
up.
Wait until the transmission
warms up.

552
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
Wa r n i n g m e s s a g eDetailsCorrection procedure
(Flashing)
The hybrid battery (trac-
tion battery) is low.
• If a buzzer sounds inter-
mittently, stop the vehicle
in a safe place and shift
lever to P to charge the
hybrid battery (traction
battery).
• If a buzzer sounds con-
tinuously, immediately
stop the vehicle in a safe
place. 
Turn the “POWER”
switch off and then to
ON mode to restart the
hybrid system. Ensuring
the shift lever is in P,
charge the hybrid bat-
tery (traction battery).
(Flashing)
The gasoline engine can-
not operate or the shift
lever is in “N” for a long
time.
Stop the vehicle and shift
the shift lever to “P”.
(Flashing)
The transmission is out of
“P” when attempting to
start the hybrid system.Shift the shift lever to “P”
before pressing the power
switch.