2008 LEXUS RX400H warning light

When trouble arises5
377
RX400h_U
5-1. Essential information .... 378If your vehicle needs to be towed ...................................... 378
If you think something is wrong ...................................... 385
Event data recorder.............. 386
5-2. Steps to take in an emergency ................... 388
If a warning light turns on or a warning buzzer
sounds... ................................. 388
If a warning message is displayed................................ 398
If you have a flat tire............... 408
If the hybrid system will not start ................................... 418
If the shift lever cannot be shifted from P ........................ 419
If you lose your keys .............. 420
If the 12-volt battery is discharged ............................. 421
If your vehicle overheats ..... 424
If the vehicle becomes stuck......................................... 427

388
RX400h_U
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 vehicle in a safe place and contact your Lexus
dealer.
*: Parking brake engaged warning buzzer:
→P. 4 0 2
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Brake system warning light (warning buzzer)*
•Low brake fluid
• Malfunction in the electronically controlled 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.
(U.S.A.)

(Canada)Brake system warning lightIndicates a malfunction in the vehicle’s brake system.
Calmly perform the following actions if any of the warning lights turn on or
flash. If a light turns on or flashes, but then turns off, this does not necessar-
ily indicate a malfunction in the system.

5
When trouble arises
389
5-2. Steps to take in an emergency
RX400h_U
Stop the vehicle immediately.The following warnings indicate the possibility of damage to the vehicle
that may lead to an accident. Immediately stop the vehicle in a safe place
and contact your Lexus dealer.
Have the vehicle inspected by yo ur Lexus dealer 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 lightWarning light/Details
Charging system warning light Indicates a malfunction in the vehicle’s charging system.
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Malfunction indicator lampIndicates a malfunction in:
• The electronic engine control system or
• The electronic throttle control system.
Hybrid battery warning lightIndicates a malfunction in the vehicle’s hybrid battery.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system.

390
5-2. Steps to take in an emergency
RX400h_U
Warning lightWarning light/Details
(U.S.A.)

(Canada)
ABS warning lightIndicates a malfunction in:
•The ABS;
• The brake assist system.
Brake system warning lightIndicates a malfunction in:
• Electronically controlled brake system; or
• Regenerative brake system.
Electric power steering warning lightMalfunction in the EPS.

5
When trouble arises
391
5-2. Steps to take in an emergency
RX400h_U
Follow the correction procedures.After taking the specified steps to co rrect the suspected problem, check
that the warning light turns off.
Warning lightWarning light/DetailsCorrection procedure
Open door warning light
(warning buzzer)
Indicates that one or more of
the doors is not fully closed.
Close the indicated doors.
Low fuel level warning lightRemaining fuel
(Approximately 2.6 gal.
[9.8L, 2.2 Imp.gal.] or less)
Refuel the vehicle.
Driver’s seat belt reminder
light (warning buzzer)*1
Warns the driver to fasten
his/her seat belt.Fasten the seat belt.
Front passenger’s seat belt
reminder light (warning
buzzer)*
2
Warns the front passenger to
fasten his/her seat belt.
Fasten the seat belt.

392
5-2. Steps to take in an emergency
RX400h_U
*1:Driver’s seat belt reminder:The driver’s seat belt reminder sounds to alert the driver that his or her seat belt
is not fastened. Once the engine switch is turned to the ON or START position,
the buzzer sounds for 4 to 8 seconds. If the vehicle has reached a speed of at
least 12 mph (20 km/h), the buzzer sounds intermittently for 10 seconds. Then,
if the seat belt is still unfastened, the buzzer will sound in a different tone for 20
more seconds.
*
2: Front passenger’s seat belt reminder:
The front passenger’s seat belt reminder sounds to alert the front passenger that
his or her seat belt is not fastened. The buzzer sounds intermittently for 10 sec-
onds after the vehicle has reached a speed of at least 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.
Warning lightWarning light/DetailsCorrection procedure
Tire pressure warning light
When the light comes on:
Low tire inflation pressure.Adjust the tire inflation pres-
sure.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system
Have the system inspected by
your Lexus dealer.
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.
Take appropriate action in
accordance with the message
displayed on the multi-infor-
mation display.

5
When trouble arises
393
5-2. Steps to take in an emergency
RX400h_U
■Key reminder buzzer
The buzzer indicates that the key has not been removed from the engine switch
(with the engine switch in the ACC or LOCK position and the driver’s door
opened).
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is your vehicle low on gas?
If it is, refuel the vehicle immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The lamp will go off after taking several driving trips.
If the light does not go off even after several trips, contact your Lexus dealer as soon
as possible.
■Front passenger detection sensor and passenger seat belt reminder
●If luggage is placed on the front passenger seat, the front passenger detection
sensor may cause the warning light to flash, even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the
warning light may not operate properly.
■Changing the engine oil (U.S.A. only)
Make sure to reset the oil change system. ( →P. 3 2 1 )
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure 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
leaks or tire inflation pressure changes caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the warning light (after a few minutes).

394
5-2. Steps to take in an emergency
RX400h_U
■When a tires is replaced with a spare tire
The spare tire is also equipped with the tire pressure warning valve and transmitter.
The tire pressure warning light will turn on if the tire inflation pressure of the spare
tire is low. If a tire goes flat, even though the flat tire is replaced with the spare tire,
the tire pressure warning light does not turn off. Replace the spare tire with the
repaired tire and adjust the proper tire inflation pressure. The tire pressure warning
light will turn off after a few minutes.
■If the tire pressure warning system is inoperative
The tire pressure warning system will be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If tires not equipped with tire pressure warning valves and transmitters are used.
●If the ID code on the tire pressure warning valves and transmitters is not regis-
tered in the tire pressure warning computer.
●If the tire pressure warning select switch is set to a different tire setting.
●If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher.
The tire pressure warning system may be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If electronic devices or facilities using similar radio wave frequencies are nearby.
●If a radio set at similar frequencies is in use in the vehicle.
●If a window tint that affects the radio wave signals is installed.
●If there is a lot of snow or ice on the vehicle, in particular around the wheels or
wheel housings.
●If non-genuine Lexus wheels are used. (Even if you use Lexus wheels, the tire
pressure warning system may not work properly with some types of tires.)
●If tire chains are used.
●If the spare tire is in a location subject to poor radio wave signal reception.
●If a large metallic object which can interfere with signal reception is put in the
trunk.
■If the tire pressure warning light comes on after blinking for 1 minute frequently
If the tire pressure warning light comes on after blinking for 1 minute frequently
when the engine switch is turned to ON position, have it checked by your Lexus
dealer.