2015 LEXUS RX450h warning light

6774-3. Do-it-yourself maintenance
4
Maintenance and care CAUTION■
Tire pressure warning system operation
The tire pressure warning system may not provide warning immediately if a tire
bursts or if sudden air leakage occurs.■
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 we ll as dangerous handling characteristics,
which may lead to an accident resu lting in death or serious injury.●
Do not mix tires of different makes, mode ls or tread patterns. Also, do not mix
tires of remarkably different treadwear.●
Do not use tire sizes other th an 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.●
Do not tow if your vehicle has a compact spare tire installed.■
When initializing the tire pressure warning system
Do not push 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.

7014-3. Do-it-yourself maintenance
4
Maintenance and care 7
ECU-IG1 NO. 1 10 A Multiplex communication system,
steering sensor, shift lock control sys-
tem, tilt and telescopic steering,
power back door, pre-collision sys-
tem, vehicle dynamics integrated
management, tire pressure warning
system8
S/ROOF 30 A Moon roof9
FUEL OPN 7. 5 A Fuel filler door opener10
PSB 30 A Pre-collision seat belt11
TI & TE 30 A Tilt and telescopic steering system12
DR LOCK 10 A13
FR FOG 7. 5 A Front fog lights14
P-S E AT L H 30 A Po w e r s e a t ( l e f t - s i d e )15
4WD 7. 5 A AW D s y s t e m16
INVERTER 20 A Po w e r o u t l e t17
RR FOG 7. 5 A18
D/L ALT B 25 A Multiplex communication system,
power door lock system, power back
door19
EPS 10 A Electric power steering system20
ECU-IG1 NO. 2 10 A Intuitive parking assist, pre-collision
seat belt, capacitor
21
PA N E L 10 A Switch illumination, navigation system,
hybrid transmission system, audio sys-
tem, multi-information display, air con-
ditioning system, multiplex
communication systemFuse Ampere Circuit

When trouble arises
5
7235-1. Essential information
Emergency flashers............... 724
If your vehicle needs to be
towed ...................................... 725
If you think something is
wrong ...................................... 732 5-2. Steps to take in an
emergency
If a warning light turns on
or a warning buzzer
sounds... ................................. 733
If a warning message is
displayed................................. 743
If you have a flat tire................ 764
If the hybrid system will
not start ................................... 777
If the shift lever cannot be
shifted from P ........................ 779
If you lose your keys .............. 780
If the electronic key does
not operate properly........... 781
If the vehicle 12-volt
battery is discharged ......... 784
If your vehicle overheats ..... 788
If the vehicle becomes
stuck........................................ 793
If your vehicle has to
be stopped in an
emergency ............................ 795

5
When trouble arises
7335-2. 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 vehi cle in a safe place and contact your Lexus
dealer.
* : Parking brake engaged warning buzzer
 P. 74 8
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 light Warning 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.
Warning light Warning light/Details
Charging system warning light
Indicates a malfunction in the vehicle’s charging systemCalmly perform the following actions if any of the warning lights comes on
or flashes. If a light comes on or flashes, but then goes off, this does not nec-
essarily indicate a malfunction in the system.

7345-2. Steps to take in an emergency
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. Warning light Warning light/Details
(U.S.A.)
(Canada) Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The emission control system
SRS warning light
Indicates a 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
Indicates a malfunction in:
•The ABS; or
• The brake assist system
Brake system warning light
Indicates a malfunction in:
• The regenerative brake system; or
• The electronically controlled brake system
Electric power steering system warning light (warning
buzzer)
Indicates a malfunction in the EPS (Electric Power Steering)
system

5
When trouble arises
7355-2. Steps to take in an emergency
(Flashes) Pre-collision system warning light (if equipped)
Indicates a malfunction in the pre-collision system
The warning light will operate as follows, even when the sys-
tem is not malfunctioning:
• The light will flash quickly wh en the system is operating.
(  P. 2 7 8 )
• The light will turn on when the pre-collision braking is dis-
abled. (  P. 2 7 9 )
• The light will turn on when the system cannot temporarily
be used. (  P. 74 8 )
Slip indicator
Indicates a malfunction in:
• The VSC system;
•The TRAC system; or
• The hill-start assist control systemWarning light Warning light/Details

7365-2. Steps to take in an emergency
Follow the correction procedures.
After taking the specified steps to co rrect the suspected problem, check
that the warning light goes off.Warning light Warning light/Details Correction procedure
Open door warning light
(warning buzzer)
* 1
Indicates that one or more of
the doors is not fully closed. Check that all the doors are
closed.
Low fuel level warning light
Indicates remaining fuel is
approximately 2.7 gal. (10.1 L,
2.2 Imp. gal.) or less Refuel the vehicle.
(On the instru-
ment panel) Driver’s seat belt reminder
light (warning buzzer)
* 2
Warns the driver to fasten
his/her seat belt. Fasten the seat belt.
(On the center
panel) Front passenger’s seat belt
reminder light
(warning buzzer)
* 2
Warns the front passenger to
fasten his/her seat belt. Fasten the seat belt.
Master warning light
A buzzer sounds and the
warning light comes on and
flashes to indicate that the
master warning system has
detected a malfunction.  P. 74 3

5
When trouble arises
7375-2. Steps to take in an emergency
* 1
: Open door warning buzzer:
The open door warning buzzer sounds to alert one or more of the doors is not
fully closed (with the vehicle having reached a speed of 3 mph [5 km/h]).
(  P. 74 8 )
* 2
: Driver's and front passenger’s seat belt buzzer:
The driver’s and front passenger’s seat belt buzzer sounds to alert the driver and
front passenger that his or her seat belt is not fastened. The buzzer sounds inter-
mittently for 10 seconds after the vehicle reaches a speed of 12 mph (20 km/h).
Then, if the seat belt is still unfastened , the buzzer will sound in a different tone
for 20 more seconds. Tire pressure warning light
When the light comes on:
Low tire inflation pressure
such as
• Natural causes (  P. 7 3 9 )
• Flat tire (  P. 76 4 ) Adjust the tire inflation pres-
sure (including the full-size
spare tire) to the specified
level.
The light will turn off after a
few minutes. In case the light
does not turn off even if the
tire inflation pressure is
adjusted, have the system
checked by your Lexus
dealer.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system
(  P. 74 0 ) Have the system checked by
your Lexus dealer.Warning light Warning light/Details Correction procedure