Check system LEXUS RX400H 2008 Owner's Guide

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Emission inspection and maintenance (I/M) programs
Some states have vehicle emission inspection programs which include
OBD (On Board Diagnostics) checks. The OBD system monitors the oper-
ation of the emission control system.
■If the malfunction indicator lamp comes on
The OBD system determines that a problem exists somewhere in
the emission control system. Your vehicle may not pass the I/M test
and may need to be repaired. Cont act your Lexus dealer to service
the vehicle.
■ Your vehicle may not pass the I/M test:
●When the 12-volt battery is disconnected or discharged
Readiness codes that are set du ring ordinary driving are erased.
Also, depending on your driving habits, the readiness codes may
not be completely set.
● When the fuel tank cap is loose
The malfunction indicator lamp comes on as a temporary mal-
function and your vehicle may not pass the I/M test.
■ When the malfunction indicator la mp goes off after several driv-
ing trips
The error code in the OBD system will not be cleared unless the
vehicle is driven 40 or more times.
■ If your vehicle does not pass the I/M test
Contact your Lexus dealer to prepare the vehicle for re-testing.

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■If the coolant level drops within a short time after replenishing
Visually check the radiator, hoses, reservoir cap, radiator cap, drain cock and water
pump.
If you cannot find a leak, have your Lexus dealer pressure test the cap and check for
leaks in the cooling system.
■Coolant selection
Only use Toyota Super Long Life Coolant or similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life
hybrid organic acid technology.U.S.A.: Toyota Super Long Life Coolant is a mixture of 50% coolant and 50% deionized water. (Enabled: -31 °F [-35 °C])
Canada: Toyota Super Long Life Coolant is a mixture of 55% coolant and 45% deionized water. (Enabled: -44 °F [-42 °C])
For more details about coolant, contact your Lexus dealer.
CAUTION
■When the coolant may be hot
Do not remove the radiator cap.
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing burns or other injuries.
NOTICE
■When adding the coolant
Coolant is neither plain water not straight antifreeze. The correct mixture of water
and antifreeze must be used to provide proper lubrication, corrosion protection
and cooling. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it damaging parts or paint.

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Radiator and condenserCheck the radiator and condenser and clear any foreign objects.
If either of the above parts are extremely dirty or you are not sure of their
condition, have your vehicle checked by your Lexus dealer.
Brake fluid■ Checking fluid level
The brake fluid level should be between the MAX and MIN lines on
the tank.
MAX
MIN
If the level is low, take your vehicle
to a Lexus dealer as soon as possi-
ble. Do not drive your vehicle if the
red brake system warning light is
on. Call a Lexus dealer for assis-
tance.
Make sure to check the fluid type.
CAUTION
■When the engine is hot
Do not touch the radiator or condenser, as they may be hot and you may be burned.

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Tires
Replace or rotate tires in accordance with maintenance schedules and
treadwear.
■Checking tires
New tread
Treadwear indicator
Worn tread
The location of treadwear indi-
cators is shown by the “TWI” or
“∆ ” marks, etc., molded on the
sidewall of each tire.
Check spare tire condition and
inflation pressure if not rotated.
■ Tire rotation
Rotate the tires in the order
shown.
To equalize tire wear and extend
tire life, Lexus recommends that
tire rotation is carried out at the
same interval as tire inspection.
■The tire pressure warning system
Your Lexus is equipped with a tire pressure warning system that uses
tire pressure warning valves and transmitters to detect low tire infla-
tion pressure before serious problems arise. ( →P. 391, 398)
Front

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Selecting ID codes
When replacing tires, make sure to select the ID code set that matches
the new tire set. If the tire pressure select switch is set to the wrong tire
setting, the tire pressure warning system will not operate properly.
After driving for about 20 minutes, the tire pressure warning light
comes on after blinking for 1 minute to indicate a system malfunction.
“MAIN”
“2nd”
■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 fab-
ric or bulges indicating internal damage.
●A tire goes flat repeatedly or cannot be properly repaired due to the size or loca-
tion of a cut or other damage.
If you are not sure, consult with your Lexus dealer.
■Replacing tires and wheels
If the ID code of the tire pressure warning valve and transmitter is not registered,
the tire pressure warning system will not work properly. After driving for about 20
minutes, the tire pressure warning light comes on after blinking for 1 minute to indi-
cate a system malfunction.
■Tire life
Any tire over 6 years old must be checked by a qualified technician even if they
have seldom or never been us ed or damage is not obvious.
■If the tread wears down below 0. 16 in. (4 mm) on snow tires
The effectiveness of snow tires is lost.

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■Maximum load of tire
Check that the maximum load of the replaced tire is greater than 1 /2 of the Gross
Axle Weight Ratings (GAWR) of either the front axle or the rear axle, whichever is
greater.
As for the maximum load of the tire, see the load limit at maximum cold tire inflation
pressure mentioned on the sidewall of the tire, and as for the Gross Axle Weight
Ratings (GAWR), see the Certification Label. (
→P. 3 4 0 , 4 4 5 ) .
■Tire types
1 Summer tiresSummer tires are high-speed performance tires best suited to highway driving
under dry conditions. Since summer tires do not have the same traction perfor-
mance as snow tires, summer tires are inadequate for driving on snow-covered
or icy roads. For driving on snow-covered roads or icy roads, the use of snow tires
is recommended. When installing snow tires, be sure to replace all four tires.
2 All season tires All season tires are designed to provide better traction in snow and to be ade-
quate for driving in most winter conditions, as well as for use year round. All sea-
son tires, however, do not have adequate traction performance compared with
snow tires in heavy or loose snow. Also, al l season tires fall short in acceleration
and handling performance compared with summer tires in highway driving.
3Snow tires
For driving on snow-covered roads or icy roads, we recommend using snow tires.
If you need snow tires, select tires of the same size, construction and load capac-
ity as the originally installed tires. Since your vehicle has radial tires as original
equipment, make sure your snow tires also have radial construction. Do not install
studded tires without first checking local regulations for possible restriction.
Snow tires should be installed on all wheels. ( →P. 1 8 2 )
■Initializing the tire pressure warning system
Initialize the tires with the tire inflation pressure adjusted to the specified level.

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■If you push the tire pressure warning reset switch accidentally
If initialization is performed, adjust the tire inflation pressure to the specified level
and initialize the tire pressure warning system again.
■When the initialization of the tire pressure warning system has failed
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 your Lexus dealer.
●When operating the tire pressure warning reset switch, the tire pressure warning
light does not flash 3 times.
●After carrying out the initialization procedure, the tire pressure warning light
blinks for 1 minute then stays on after driving for about 20 minutes.
■Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pressure
checks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.
■Tire pressure warning system certificationFor vehicles sold in the U.S.A.
This device complies with Part 15 of the FCC Rules. Operation is subject to the fol-
lowing two conditions: (1) this device may not cause harmful interference, and (2)
this device must accept any interference received, including interference that may
cause undesired operation.
NOTICE:
This equipment has been tested and found to comply with the limits for a Class B
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference in a residential installa-
tion. This equipment generates, uses and can radiate radio frequency energy and, if
not installed and used in accordance with the instructions, may cause harmful inter-
ference to radio communications. However, there is no guarantee that interference
will not occur in a particular installation. If this equipment does cause harmful inter-
ference to radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the interference by
one or more of the following measures:
●Reorient or relocate the receiving antenna.
●Increase the separation between the equipment and receiver.

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Wheels
■When replacing wheels
The wheels of your Lexus are equipped with tire pressure warning valves and trans-
mitters that allow the tire pressure warning system to provide advanced warning in
the event of a loss in tire inflation pressure. Whenever wheels are replaced, the tire
pressure warning valves and transmitters must be installed. (→P. 3 3 2 )
If a wheel is bent, cracked or heavily corroded, it should be replaced. Oth-
erwise, the tire may separate from the wheel or cause loss of handling con-
trol.
■Wheel selection
When replacing wheels, care should be taken to ensure that they
are equivalent to those removed in load capacity, diameter, rim
width, and offset.
Replacement wheels are available at your Lexus dealer.
Lexus does not recommend using:
• Wheels of different sizes or types
• Used wheels
• Bent wheels that have been straightened
■ Aluminum wheel precautions
● Use only Lexus wheel nuts and wrenches designed for use with
your aluminum wheels.
● When rotating, repairing or changing your tires, check that the
wheel nuts are still tight after driving 1000 miles (1600 km).
● Be careful not to damage the aluminum wheels when using tire
chains.
● Use only Lexus genuine balance weights or equivalent and a
plastic or rubber hammer when balancing your wheels.

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■Changing interval
Inspect and replace the air conditioning filter according to the maintenance sched-
ule. In dusty areas or areas with heavy traffic flow, early replacement may be
required. (For scheduled maintenance information, please refer to the “Warranty
and Service Guide”, “Owner's Manual Supplement” or “Scheduled Maintenance”.)
■If air flow from the vents decreases dramatically
The filter may be clogged. Check the filter and replace if necessary.
NOTICE
■When using the air conditioning system
Make sure that a filter is always installed.
Using the air conditioning system without a filter may cause damage to the system.

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Driver's side instrument panelRemove the lid.
After a system failure, see “Fuse layout and amperage ratings”
(→ P. 355) for details about which fuse to check.
Remove the fuse with the pull-
out tool.
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