2012 Lexus GS250 warning light

3574-5. Using the driving support
4
Driving
GS350/250_EE (OM30C36E)
Conditions under which the Blind Spot Monitor system may not function cor-
rectly
The Blind Spot Monitor system may not detect vehicles correctly in the fol-
lowing conditions:
• During bad weather such as heavy rain, fog, snow etc.
• When ice or mud etc. is attached to the rear bumper
• When driving on a road surface that is wet due to rain, standing water
etc.
• When there is a significant difference in speed between your vehicle and
the vehicle that enters the detection area
• When a vehicle is in the detection area from a stop and remains in the
detection area as your vehicle accelerates
• When driving up or down consecutive steep inclines, such as hills, a dip
in the road etc.
• When multiple vehicles approach with only a small gap between each
vehicle
• When vehicle lanes are wide, and the vehicle in the next lane is too far
away from your vehicle
• When the vehicle that enters the detection area is traveling at about the
same speed as your vehicle
• When there is a significant difference in height between your vehicle and
the vehicle that enters the detection area
• Directly after the BSM switch is set to on
• When your vehicle is towing a trailer
Instances of the Blind Spot Monitor unnecessarily detecting a vehicle and/
or object may increase under the following conditions:
• When there is only a short distance between your vehicle and a guardrail,
wall etc.
• When there is only a short distance between your vehicle and a following
vehicle
• When vehicle lanes are narrow and a vehicle driving 2 lanes across from
your vehicle enters the detection area
The outside rear view mirror indicators visibility
When under strong sunlight, the outside rear view mirror indicator may be
difficult to see.
When there is a malfunction in the system
If a system malfunction is detected due to any of the following reasons,
warning messages will be displayed: (P. 762, 768)
There is a malfunction with the sensors
The sensors have become dirty

6746-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)Your vehicle is equipped with a tire pressure warning system that
uses tire pressure warning valves and transmitters to detect low tire
inflation pressure before serious problems arise.
Vehicles without the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver is
warned by a warning light. (P. 753)
Vehicles with the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver
is warned by a screen display and a warning light. (P. 772)
The tire pressure detected by the tire pressure warning system
can be displayed on the multi-information display. (P. 106)
Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and
transmitters must also be installed.
When new tire pressure warning valves and transmitters are
installed, new ID codes must be registered in the tire pressure
warning computer and the tire pressure warning system must be
initialized. Have tire pressure warning valve and transmitter ID
codes registered by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional. (P. 676)
Tire pressure warning system (if equipped)

6766-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)Press and hold the tire pres-
sure warning reset switch
until the tire pressure warn-
ing light blinks slowly 3
times.
Wait for a few minutes with the engine switch in IGNITION
ON mode and then turn the engine switch off.
Registering ID codes
The tire pressure warning valve and transmitter is equipped with
a unique ID code. When replacing a tire pressure warning valve
and transmitter, it is necessary to register the ID code. Have the
ID code registered by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
4
5

677 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS350/250_EE (OM30C36E)
When to replace your vehicle’s tires
Tires should be replaced if:
You have tire damage such as cuts, splits, cracks deep enough to expose the
fabric, and bulges indicating internal damage
A tire goes flat repeatedly or cannot be properly repaired due to the size or
location of a cut or other damage
If you are not sure, consult with any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Replacing tires and wheels (vehicles with the tire pressure warning system)
If the ID code of the tire pressure warning valve and transmitter is not regis-
tered, the tire pressure warning system will not work properly. After driving
for about 10 minutes, the tire pressure warning light blinks for 1 minute and
stays on to indicate a system malfunction.
Tire life
Any tire over 6 years old must be checked by a qualified technician even if it
has seldom or never been used or damage is not obvious.
Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pres-
sure checks. Make sure to check tire inflation pressure as part of your routine
of daily vehicle checks.
When rotating the tires (vehicles with the tire pressure warning system featur-
ing a tire inflation pressure display function)
Make sure that the engine switch is off. If the tires are rotated while the
engine switch is in IGNITION ON mode, the tire position information will
not be updated.
If this accidentally occurs, either turn the engine switch to off and then to
IGNITION ON mode, or initialize the system after checking that the tire
pressure is properly adjusted.

6806-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
The initialization operation (vehicles with the tire pressure warning system)
Make sure to carry out initialization after adjusting the tire inflation pres-
sure.
Also, make sure the tires are cold before carrying out initialization or tire
inflation pressure adjustment.
If you have accidentally turned the engine switch off during initialization, it
is not necessary to press the reset switch again as initialization will restart
automatically when the engine switch has been turned to IGNITION ON
mode for the next time.
If you accidentally press the reset switch when initialization is not neces-
sary, adjust the tire inflation pressure to the specified level when the tires
are cold, and conduct initialization again.
Warning performance of the tire pressure warning system (if equipped)
The warning of the tire pressure warning system will change in accordance
with the conditions under which it was initialized. For this reason, the system
may give a warning even if the tire pressure does not reach a low enough
level, or if the pressure is higher than the pressure that was adjusted to when
the system was initialized.
When initialization of the tire pressure warning system has failed (vehicles
with the tire pressure warning system)
Initialization can be completed in a few minutes. However, in the following
cases, the settings have not been recorded and the system will not operate
properly. If repeated attempts to record tire inflation pressure settings are
unsuccessful, have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
When operating the tire pressure warning reset switch, the tire pressure
warning light does not blink 3 times.
After carrying out the initialization procedure, the tire pressure warning
light blinks for 1 minute then stays on after driving for 10 minutes.

687 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS350/250_EE (OM30C36E)
CAUTION
When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as dan-
gerous handling characteristics, which may lead to an accident resulting in
death or serious injury.
Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
Do not use tire sizes other than those recommended by Lexus.
Do not mix differently constructed tires (radial, bias-belted or bias-ply
tires).
Do not mix summer, all season and snow tires.
Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
Vehicles with a compact spare tire: Do not tow if your vehicle has a com-
pact spare tire installed.
Vehicles with an emergency tire puncture repair kit (if equipped): Do not
tow anything if a tire that has been repaired using the emergency tire
puncture repair kit is installed. The load on the tire may cause unexpected
damage to the tire.
When initializing the tire pressure warning system (vehicles with the tire
pressure warning system)
Do not operate the tire pressure warning reset switch without first adjusting
the tire inflation pressure to the specified level. Otherwise, the tire pressure
warning light may not come on even if the tire inflation pressure is low, or
it may come on when the tire inflation pressure is actually normal.

7186-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
Right-hand drive vehicles
FuseAmpereCircuit
1STOP7.5Stop lights, high mounted stoplight
2P/SEAT1 F/R30Power seats
3FR P/OUTLET15Power outlet (front)
4P/W-B5Power window master switch
5RR P/OUTLET15Power outlet (rear)
6P/SEAT2 F/R25Power seats
7AV S20AV S
8WIPER30Windshield wipers
9WA S H20Windshield washer
10RH ECU-IG10
Navigation system, VDIM, D-SW
MODULE (Blind Spot Monitor, heated
steering wheel)
11RH-IG10
Tension reducer, AWD system, power
seats, head-up display, front right-hand
door ECU, nanoe, shift lock system,
electric tilt and telescopic steering col-
umn, seat heater/ventilator switches,
smart entry & start system antennas, tire
pressure warning system receiver, driver
monitor system
12DOOR FR30
Front right-hand door control system
(outside rear view mirror defoggers,
power window)

7206-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
Trunk
FuseAmpereCircuit
1PSB30Pre-crash seat belts
2PTL25Power trunk lid
3RR J/B-B10Smart entry & start system
4RR S/HTR20Seat heaters (rear)
5FR S/HTR10Seat heaters/ventilators (front)
6RR FOG10Rear fog light
7DC/DC-S (HV)7.5No circuit
8BATT FAN (HV)20No circuit
9SECURITY7.5SECURITY
10ECU-B NO.37.5Parking brake
11TRK OPN7.5Power trunk lid
12DCM (HV)7.5No circuit
13AC INV (HV)20No circuit
14RR-IG15Radar sensor, Blind Spot Monitor
15RR ECU-IG10
Power trunk lid, parking brake, tension
reducer (rear left-hand), RR CTRL SW,
tire pressure warning system
16EPS-IG5Electric power steering system
17BACK UP7.5Back-up light