light Lexus GX470 2007 Using other driving systems /

126
2-4. Using other driving systems
■If the vehicle height does not change
If the area around the rear suspension is coated with ice, or the undercarriage has
come into contact with the road surface, the rear height control suspension will not
operate. In this case, the indicator lights will change as follows:
●The current mode indicator light will turn off, and the target mode indicator light
will begin flashing.
●The target mode indicator light will turn off, and the original mode indicator light
will be lit once more. (The vehicle height does not change.)
If the rear height control air suspension cannot be operated even after removing
the ice or progressing to a smooth driving surface, turn off and restart the engine.
■ Parking and stopping tips
●If you immediately stop the engine after of f-road driving, or park the vehicle for
a long time, the vehicle height may gradually lower. When parking, make sure
there is nothing under the vehicle that may come in contact with the underbody.
The vehicle will return to the set height when the engine is started.
●The vehicle height may change as the temperature changes when the engine is
stopped. The vehicle will return to the set height when the engine is started.
■When lowering the vehicle
Even if the engine is stopped while the ve hicle height is being lowered, operation
will continue for up to 25 seconds. If any of the side doors or the back door is
opened within this 25 seconds, operatio n will continue for a further 15 seconds.
■ Rear height control failure warning
●If a malfunction occurs in the rear height control air suspension, normal mode is
automatically selected.
The height control “OFF” indicator will blink, and the vehicle height control can-
not be activated until the malfunction is corrected. Have the vehicle checked at
your Lexus dealer as soon as possible.
●If the height control “OFF” indicator li ght does not come on when the ignition
switch is turned to the “ON” position, there is a malfunction in the rear height
control air suspension. You can continue normal driving, however have the vehi-
cle checked by your Lexus dealer as soon as possible.

128
2-4. Using other driving systems
NOTICE
■To avoid damage to the vehicle
●If in the low mode, the vehicle automatically shifts to the normal mode (vehicle
height is raised) when the engine is started. Take care when overhead height is
limited.
●After unloading, the vehicle height may be slightly higher than normal. Take care
when overhead height is limited.
●Before lowering the vehicle height, check that no-one is under the vehicle and
the area is free of obstructions. Also check that the underbody of the vehicle will
not touch the ground.
●Do not select the low mode when drivin g on bumpy roads, as the underbody of
the vehicle may contact the road surface.
■ Avoid rapid changes to the vehicle height when the vehicle is heavily loaded
As the compressor may overheat, causing the vehicle height adjustment operation
to stop.

130
2-4. Using other driving systems
DAC (Downhill Assist Control system)
The DAC system helps to prevent excessive speed on steep downhill
slopes.
The system will operate when the vehicle is traveling under 15 mph
(25km/h) and the four wheel drive control lever is in the “L” position.
■System operation
Press the “DAC” switch. The
indicator will come on, and the
system will operate.
When the system is in operation,
the slip indicator light will flash,
and the stop lights/high
mounted stop lights will be lit.
■Turning off the system
Press the “DAC” switch while the system is in operation. The indica-
tor will flash as the system gradua lly ceases operation, and will turn
off when the system is fully off.
Press the “DAC” switch while the indicator is flashing to start the
system again.

133
2-4. Using other driving systems
2
When driving
When the VSC/TRAC/hill-start assist control systems are operating
If the vehicle is in danger of slip-
ping, rolling backwards when
starting on an incline, or if the rear
wheels spin, the slip indicator light
flashes to indicate that the VSC/
TRAC/hill-start assist control sys-
tems have been engaged.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
The stop lights and high mounted
stoplight turn on when the hill-start
assist control system is operating.
The slip indicator light flashes as
well when ABS is operating.
■Sounds and vibrations caused by the ABS, BA, VSC, TRAC and hill-start assist
control systems
●A sound may be heard from the engi ne compartment when the engine is
started or just after the vehicle begins to move. This sound does not indicate that
a malfunction has occurred in any of these systems.
●Any of the following conditions may occur when the above systems are operat-
ing. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after the ABS is activated.
• The brake pedal may move down s lightly after the ABS is activated.
■Hill-start assist control is operational when
●The shift lever is in any of the positions “D”, “4”, “3”, “2” or “L”.
●The brake pedal is not depressed.

134
2-4. Using other driving systems
CAUTION
Any of the following conditions may result in an accident which could cause death or
serious injury:
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded.
●The vehicle hydroplanes while driving at high speed on the wet or slick road.
■Stopping distance when the ABS is operating on the wet or slick roads
The ABS is not designed to shorten the vehicle’s stopping dist ance. Always main-
tain a safe distance from the vehicle in front of you in the following situations.
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or roads with uneven roads
■TRAC may not operate effectively when
Directional control and power may not be ac hievable while driving on slippery road
surfaces, even if the TRAC is operating.
Do not drive the vehicle in conditions where stability and power may be lost.
■The hill-start assist control may not operate effectively when
●On steep inclines.
●On icy surfaces.
■When the VSC is activated
The slip indicator light flashes and a warning buzzer sounds. Always drive carefully.
Reckless driving may cause an accident. Exercise particular care when the indica-
tor light flashes and a buzzer sounds.
■Replacing tires
Make sure that all tires are of the same size, brand, tread pattern and total load
capacity. In addition, make sure that the ti res are inflated to the specified tire pres-
sure level.
The ABS and VSC will not function correctly if different tires are fitted on the vehi-
cle.
Contact your Lexus dealer for further info rmation when replacing tires or wheels.

153
2-5. Driving information
2
When driving
Connecting trailer lightsUse the wire harness stored in the rear end underbody.
■When connecting and disconnecting a trailer
Connecting Set the rear height control air suspension to “LO” mode.
Turn off the ignition switch or the rear height control air suspension.
Connect the trailer.
Turn on the switch that was turned off on STEP 2.
Set the rear height control air suspension to “N” mode.
Disconnecting Set the rear height control air suspension to “LO” mode.
Turn off the ignition switch or the rear height control air suspension.
Set the supporting leg of the trailer on the ground and raise the hitch by
4 in. (100 mm).
Turn on the switch that was turned off on STEP 2.
Wait until vehicle height is stabilized.
Make sure the hitch is disconnected. If the hitch does not disconnect, raise
the hitch higher and repeat steps 2 through 5.
Move the vehicle forward in the “LO” mode where the hitch does not
touch anything in the “N” mode.
Set the rear height control air suspension in the “N” mode.
STEP1STEP1
STEP2STEP2
STEP1STEP3STEP3
STEP1STEP4STEP4
STEP1STEP5STEP5STEP5
STEP1STEP1
STEP2STEP2
STEP1STEP3STEP3
STEP1STEP4STEP4
STEP1STEP5STEP5STEP5
STEP1STEP5STEP6STEP6STEP6
STEP1STEP5STEP6STEP7STEP7
STEP1STEP5STEP6STEP8STEP8

154
2-5. Driving information
■Before towing
Check that the following conditions are met:
●The vehicle’s tires are properly inflated. (P. 3 8 5 )
●Trailer tires are inflated according to the trailer manufacturer’s recommenda-
tion.
●All trailer lights work.
●All lights work each time you connect them.
●The trailer ball is set up at the proper height for the coupler on the trailer.
●The vehicle remains level when a loaded or unloaded trailer is hitched. Do not
drive if the vehicle is not level, and check for improper tongue load, overloading,
worn suspension, or other possible causes.
●The trailer cargo is securely loaded.
●The rear view mirrors conform to all applicable federal, state/provincial or local
regulations. If they do not, install rear view mirrors appropriate for towing pur-
poses.
■Break-in schedule
Lexus recommends that you do not use a new vehicle or a vehicle with any new
power train components (engine, transmission, differential, wheel bearings, etc.) to
tow a trailer for the first 500 miles (800 km) of driving.
■Maintenance
●If you tow a trailer, your vehicle will require more frequent maintenance due to
the additional load. (See “Warranty and Services Guide/Owner’s Manual Sup-
plement/Scheduled Maintenance”.)
●Retighten the fixing bolts of the towing ball and bracket after approximately
600 miles (1000 km) of trailer towing.

155
2-5. Driving information
2
When driving
CAUTION
■To avoid accident or injury
●The total trailer weight (trailer weight plus the weight of cargo) must not exceed
6500 lb. (2948 kg).
●If a trailer and cargo weight over 2000 lb. (907 kg), use a sway control device
with sufficient capacity.
●The gross combined weight (sum of your vehicle weight plus its load and the total
trailer weight) must not exceed 12000 lb. (5443 kg).
●Do not exceed the trailer hitch assembly weight, gross vehicle weight, gross axle
weight and trailer tongue load capacities.
●Never load more weight in the back than in the front of the trailer. About 60% of
the load should be in the front half of the trailer, and the remaining 40% in the
rear.
●Set the vehicle height to the “LO” mode and turn off the rear height control air
suspension to prevent the vehicle he ight from automatically changing.
●The tow hitch receiver installed on your vehicle must never be used on another
vehicle
■Hitches
●If you wish to install a trailer hitch, contact your Lexus dealer.
●Use only a hitch that conforms to the total trailer weight requirement.
●Follow the directions supplied by the hitch manufacturer.
●Lubricate the hitch ball with a light coat of grease.
●Remove the trailer hitch whenever you are not towing a trailer. After removing
the hitch, seal any mounting hole in the vehicle body to prevent entry of any sub-
stances into the vehicle.
■When towing a trailer
●If the total trailer weight exceeds 1000 lb . (453 kg), trailer brakes are required.
●Never tap into your vehicle’s hydraulic system, as this will lower the vehicle’s brak-
ing effectiveness.
●Never tow a trailer without using a safety chain securely attached to both the
trailer and the vehicle. If damage occurs to the coupling unit or hitch ball, there is
danger of the trailer wandering into another lane.

156
2-5. Driving information
NOTICE
■When installing a trailer hitch
●Use only the position recommended by your Lexus dealer. Do not install the
trailer hitch on the bumper; this may cause body damage.
●Do not use axle-mounted hitches, as they can cause damage to the axle housing,
wheel bearings, wheels or tires.
■Brakes
Lexus recommends trailers with brakes that conform to all applicable federal and
state/provincial regulations.
■Safety chain
A safety chain must always be used between the towing vehicle and the trailer.
Leave sufficient slack in the chain for turns. The chain should cross under the trailer
tongue to prevent the tongue from droppi ng to the ground in the case that it
becomes damaged or separated. For the correct safety chain installation proce-
dure, ask your Lexus dealer.
■Do not directly splice trailer lights
Directly splicing trailer lights may dama ge your vehicle’s electrical system and
cause a malfunction.

157
2-5. Driving information
2
When driving
Trailer towing tipsYour vehicle will handle differently when towing a trailer. The 3 main
causes of vehicle-trailer accidents are driver error, excessive speed and
improper trailer loading. Keep the following in mind when towing.
● Before starting out, check the trai ler lights and the vehicle-trailer con-
nections. Recheck after driving a short distance.
● Practice turning, stopping and reversing with the trailer attached in an
area away from traffic until you be come accustomed to the feel of the
vehicle.
● Reversing with a trailer attached is difficult and requires practice Grip
the bottom of the steering wheel and move your hand to the left to
move the trailer to the left. Move yo ur hand to the right to move the
trailer to right. (This is generally opposite to reversing without a trailer
attached.) Avoid sharp or prolon ged turning. Have someone guide
you when reversing to reduce the risk of an accident.
● As stopping distance is increased when towing a trailer, vehicle-to-
vehicle distance should be increas ed. For each 10 mph (16 km/h) of
speed, allow at least one vehicle and trailer length.
● Avoid sudden braking as you may sk id, resulting in jackknifing and loss
of control. This is especially true on wet or slippery surfaces.
● Avoid jerky starts or sudden acceleration.
● Avoid jerky steering and sharp turn s, and slow down before making
turns.