check engine LEXUS RX400H 2008 Owner's Manual

352
4-3. Do-it-yourself maintenance
RX400h_U
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have blown.
If this happens, check and replace the fuses as necessary.
Turn the engine switch to the LOCK position.
Remove the engine compartment cover. ( →P. 317)
Open the fuse box cover.
Engine compartment
Push the tabs in and lift the lid
off.STEP1
STEP2
STEP3

365
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
Light bulbs
You may replace the following bulbs yourself. For more information about
replacing other light bulbs, contact your Lexus dealer.
■Prepare a replacement light bulb.
Check the wattage of the light bulb being replaced. ( →P. 441)
■ Remove the engine compartment cover.
→ P. 317
■ Turn the power back door main switch OFF.
→ P. 4 5
■ Front bulb locations
Parking light Front turn
signal light
Front side
marker light
Headlight
low beam
(halogen bulb)
Headlight
high beam
(halogen bulb)

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.

404
5-2. Steps to take in an emergency
RX400h_U
Wa r n i n g m e s s a g eDetailsCorrection procedure
(U.S.A. only)
Indicates that the engine
oil is scheduled to be
changed.
Check the engine oil, and
change if necessary.
Comes on approximately
4500 miles (7200 km)
after the engine oil is
changed. (The indicator
will not work properly
unless the oil mainte-
nance data has been
reset.)
(U.S.A. only)
Indicates that the engine
oil should be changed.
Check and change the
engine oil.
Comes on approximately
5000 miles (8000 km)
after the engine oil is
changed (and the oil
maintenance data has
been reset).

5
When trouble arises
407
5-2. Steps to take in an emergency
RX400h_U
Have the malfunction repaired immediately.After taking the specified steps to co rrect the suspected problem, check
that the warning light turns off.
■Changing the engine oil (U.S.A. only)
Make sure to reset the oil change system. ( →P. 3 2 1 )
■Warning light display in radar cruise mode
In the following cases, the warning light may not be displayed even if vehicle-to-
vehicle distance closes.
●When your vehicle and the vehicle ahead are traveling at the same speed or the
vehicle ahead is traveling more quickly than your vehicle
●When the vehicle ahead is traveling at a very low speed
●Immediately after cruise control speed is set
●At the instant the accelerator pedal is depressed
Wa r n i n g m e s s a g eDetailsCorrection
procedure
(Comes on for 8 seconds.)
Indicates that the fuel
door left open after refuel-
ing when start the vehicle/
leave the fuel door open
for more than 30 minutes
during refueling.
Close the fuel lid.

416
5-2. Steps to take in an emergency
RX400h_U
CAUTION
■Using the tire jack
Improper use of the tire jack may lead to death or injuries due to the vehicle sud-
denly falling off the jack.
●Do not use the tire jack for any purpose other than replacing tires or installing and
removing tire chains.
●Only use the tire jack that comes with this vehicle for replacing a flat tire.
Do not use it on other vehicles, and do not use other tire jacks for replacing tires
on this vehicle.
●Always check that the tire jack is securely set to the jack point.
●Do not put any part of your body under the vehicle supported by a jack.
●Do not start or run the engine while your vehicle is supported by the jack.
●Do not raise the vehicle while someone is in it.
●When raising the vehicle, do not put an object on or under the jack.
●Do not raise the vehicle to a height greater than that required to replace the tire.
●Use a jack stand if it is necessary to get under the vehicle.
Take particular care when lowering the vehicle to ensure that no one working on or
near the vehicle may be injured.
■Replacing a flat tire
Observe the following precautions to reduce the risk of death or serious injury:
●Never use oil or grease on the wheel bolts or wheel nuts.
The oil or grease can cause the wheel nuts to loosen, causing a serious accident.
Remove any oil or grease on the wheel bolts or wheel nuts.
●Have the wheel nuts tightened with a torque wrench to 76 ft•lbf (103 N•m, 10.5
kgf•m) as soon as possible after changing wheels.
Failure to follow these precautions could cause the nuts to loosen and the wheels
may fall off, which could lead to an accident causing death or serious injury.

424
5-2. Steps to take in an emergency
RX400h_U
If your vehicle overheats
■Electric motor (traction motor) and inverter
If the message WATER TEMP is displayed on the multi-information
display.
■ Gasoline engine
If the needle of the engine coolant temperature gauge enters the
red zone, the gasoline engine has probably overheated.
Observe the following steps:
Stop the vehicle in a safe place and turn off the automatic air
conditioning system.
Check to see if steam is coming out from under the hood.
If you see steam: Stop the hybrid system. Carefully lift the hood after the
steam subsides and then restart the hybrid system.
If you do not see steam: Leave the hybrid system running and carefully lift the hood.
Check to see if the cooling fan is operating.
If the fan is operating: Wait until the temperature of the engine (shown on the
instrument cluste r) begins to fall and then stop the hybrid
system.
If the fan is not operating: Stop the hybrid system immediately and call your local
Lexus dealer.
After the hybrid system has
cooled down sufficiently, check
the engine coolant level and
inspect the radiator core (radia-
tor) for any leaks.
STEP1
STEP2
STEP3
STEP4

5
When trouble arises
425
5-2. Steps to take in an emergency
RX400h_U
■Overheating
If you observe the following, your vehicle may be overheating.
●The message WATER TEMP is displayed on the multi-information display.
●The engine coolant temperature gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
CAUTION
■To prevent an accident or injury when inspecting under the hood of your vehicle
●If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartment may be very hot, causing serious
injury such as burns.
●Keep hands and clothing away from the fan and other belts while the hybrid sys-
tem is running.
●Do not loosen the radiator cap while the hybrid system and radiator are hot.
Serious injury, such as burns, may result from hot coolant and steam released
under pressure.
Add engine coolant if required.
Water can be used in an emer-
gency measure if engine coolant
is unavailable. (→P. 4 3 5 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP5

436
6-1. Specifications
RX400h_U
Electrical system
12-volt battery
Open voltage at
68°F (20 °C):12.6  12.8 V Fully charged
12.2 
12.4 V Half charged
11.8 
12.0 V Discharged
(Voltage checked 20 minutes after the
key is removed from the engine switch
with all the lights turned off)
Charging rates5 A max.