engine LEXUS LS430 2005 Repair Manual

STARTING AND DRIVING
307
(a) Normal driving
31L321a
 1“P” (Park) position 2“N” (Neutral) position
1. Start the engine as instructed in “How to start the
engine” on page 304.
The transmission must be in “P” or “N” position. The engine wi\
ll
not start in any drive position even if the ignition switch is turned
to “START”.
31L322
 1 Power position 2Normal position
3Snow position
2. Set the driving pattern selector switch to the “Normal”
position.
Your transmission has a driving pattern selector switch which
allows you to select “Power”, “Normal” or “Snow” mode to suit\
your driving condition. For ordinary driving, Lexus
recommends that you use the “Normal” position to improve fuel
economy.
3. For more powerful acceleration and sporty driving, use
the “Power” position.
In the “Power” position, the “ECT PWR” light in the instrument
cluster is on and the transmission is shifted up at higher vehicle
speeds and shifted down more responsively than in the
“Normal” position.
For “Snow” mode, see “Electronic Throttle Control
System” on page 315.

STARTING AND DRIVING
308
31l323
 1Brake pedal 2“D” (Drive) position
4. With your foot holding down the brake pedal, shift the
selector lever to “D”.
Always use the “D” position to improve fuel economy and quiet
driving. Only in this position, shifting into the overdrive gear is
possible. However, while the engine coolant temperature is
low, the transmission will not shift into the overdrive gear even
in the “D” position. (See “(c) Using engine braking” and “(f)
Good driving practice” for exceptions.)
CAUTION
Never put your foot on the accelerator pedal while
shifting.
5. Release the parking brake and brake pedal. Depress
the accelerator pedal slowly for smooth starting.
In normal cruising, the vehicle will start in first gear and
automatically shift up to the most suitable gear. On inclines,
declines or winding roads, etc., the vehicle shifts up and down
automatically according to the running conditions to obtain the
suitable driving power and engine braking.
If you need to accelerate rapidly while driving, depress the
accelerator pedal to the full throttle position. This provides
more acceleration by auto matically downshifting the
transmission to the next lower gear or beyond, depending on
the vehicle speed.
If engine braking is needed, such as in descending a long hill,
see “(c) Using engine braking”.
 AI (Artificial Intelligence) shifting control
AI shifting control selects the most suitable shift range
automatically according to the driver’s operation and
driving condition.
AI shifting control operates automatically with the
selector lever in the “D” position. When the lever is moved
to the “S” position, this function will be canceled.
Shifting control on the slope: On inclines, you can drive
smoothly with reduced shifting quantity. On declines, the
vehicle will shift down automatically to obtain optimum engine
braking and reduce the driver’s foot braking load.
Automatic shifting point change control: The most suitable
shift range is selected depending on the driver’s accelerator
pedal operation and vehicle condition.

STARTING AND DRIVING
310“4” (fourth range):
The most suitable gear is automatically
selected between first and fourth gears according to vehicle
speed and driving conditions. In the “4” (fourth range)
position, the automatic transmission system will select the
most suitable gear to handle current running conditions
such as hill climbing, hard towing, etc.
“3” (third range): The most suitable gear is automatically
selected between first and third gears according to vehicle
speed and driving conditions. This range is best used when
stronger engine braking is necessary.
“2” (second range): First or second gear will automatically
be selected according to vehicle speed and driving
conditions. This range is to be used when engine braking
stronger than that of the “3” (third range) position is
necessary.
“1” (first range): This gear is fixed in first regardless of
vehicle speed or driving conditions. This range is to be used
when maximum engine braking is necessary.
If you attempt to downshift the transmission when it is not
possible to downshift due to high vehicle speed, a warning tone
sounds twice. 
Maximum allowable speeds
To get on a highway or to pass slower traffic, maximum
acceleration may be necessary. Make sure you observe the
following maximum allowable speeds in each range:
range km/h (mph)1 59 (36)
2 100 (62)
3 146 (90)
NOTICE
Do not downshift if you are going faster than the
maximum allowable speed for the next lower range.
 “S” mode indicator light
“S” mode allows you to use the shift range positions.
The “S” mode indicator light comes on when the selector
lever is shifted into the “S” position. When the “S” mode
indicator light does not come on even with the selector lever
moved to the “S” position, there may be a problem
somewhere in the system. Have your vehicle
checked/repaired by your Lexus dealer as soon as
possible. In this case, you can drive in the same condition
as in the “D” position.

STARTING AND DRIVING
311
(c) Using engine braking
31L327
“S” mode position
To use the braking power of the engine, downshift the range in
the “S” mode position as follows:
 Shift into the “5” (fifth range) position. The transmission will
downshift to fifth gear and engine braking will be enabled.
If you drive in the “D” position: Shift the selector lever to
the “S” position and “5” (fifth range) will automatically \
be
selected.
If you drive in the “S” position: Shift the selector lever
down to the “–” position by selecting the “5” (fifth ran\
ge). Vehicles with the cruise control —
When
the cruise control is being used, even if you downshift
from “D” or “6” (sixth range) to “5” (fifth range)\
, engine
braking will not be enabled because the cruise control is not
cancelled. For vehicle speed reduction, see page 328.
Vehicles with the dynamic radar/laser cruise control —
When the cruise control is being used in the conventional
(fixed speed) cruise control mode or in the
vehicle −to−vehicle distance control mode, even if you
downshift from “D” or “6” (sixth range) to “5” (fif\
th range),
engine braking will not be enabled because the cruise
control is not cancelled. For vehicle speed reduction, see
pages 359 and 344.
 Shift into the “4” (fourth range) position. The transmission
will downshift to fourth gear when the vehicle speed is or
becomes lower than 197 km/h (122 mph) and more
powerful engine braking will be enabled.
If you drive in the “D” position: Shift the selector lever to
the “S” position and shift the lever down to the “–” posi\
tion
once to select “4” (fourth range). However, when you move
the lever to the “S” position while the AI shifting control is
operating, the first shift range will be “5” (fifth range), “4”
(fourth r ange) or “3” (third range) because the suitable shift
range is selected depending on the driving condition.
If you drive in the “S” position: Shift the selector lever
down to the “–” position to select the “4” (fourth range\
).

STARTING AND DRIVING
312Vehicles with the cruise control —
When
the cruise control is being used, even if you downshift
from “D” or “5” (fifth range) to “4” (fourth range)\
, engine
braking will not be enabled because the cruise control is not
cancelled. For vehicle speed reduction, see page 328.
Vehicles with the dynamic radar/laser cruise control —
When the cruise control is being used in the conventional
(fixed speed) cruise control mode or in the
vehicle −to−vehicle distance control mode, even if you
downshift from “D” or “5” (fifth range) to “4” (fourth range),
engine braking will not be enabled because the cruise
control is not cancelled. For vehicle speed reduction, see
pages 359 and 344.
 Shift into the “3” (third range) position. The transmission will
downshift to third gear when the vehicle speed is or
becomes lower than 146 km/h (91 mph) and more powerful
engine braking will be enabled.
If you drive in the “D” position: Shift the selector lever to
the “S” position and shift the lever down to the “–” posi\
tion
twice to select the “3” (third range). However, when you
move the lever to the “S” position while the AI shifting control
is operating, the first shift range will be “5” (fifth range), “\
4”
(fourth range) or “3” (third range) because the suitable shift
range is selected depending on the driving condition.
If you drive in the “S” position: Shift the selector lever
down to the “–” position to select “3” (third range). 
Shift into the “2” (second range) position. The transmission
will downshift to second gear when the vehicle speed is or
becomes lower than 98 km/h (61 mph) and more powerful
engine braking than that of the “3” (third range) position will
be enabled.
If you drive in the “D” position: Shift the selector lever to
the “S” position and shift the lever down to the “–” posi\
tion
three times to select “2” (second range).
If you drive in the “S” position: Shift the selector lever
down to the “–” position to select “2” (second range).
 Shift into the “1” (first range) position. The transmission will
downshift to first gear when the vehicle speed is or becomes
lower than 35 km/h (22 mph) and maximum engine braking
will be enabled.
If you drive in the “D” position: Shift the selector lever to
the “S” position and shift the lever down to the “–” posi\
tion
four times to select “1” (first range).
If you drive in the “S” position: Shift the selector lever
down to the “–” position to select “1” (first range).
CAUTION
Be careful when downshifting on a slippery surface.
The abrupt change in engine speed could cause the
vehicle to skid or spin.

STARTING AND DRIVING
314
(e) Parking
31L325
 1Parking brake pedal 2Brake pedal
3“P” (Park) position
1. Bring the vehicle to a complete stop.
2. Depress the parking brake pedal fully to securely apply the
parking brake.
3. With the brake pedal held down with your foot, shift the
selector lever to the “P” position.
CAUTION
Never attempt to move the selector lever into “P” under
any circumstances while the vehicle is moving. Serious
mechanical damage and loss of vehicle control may
result.
(f) Good driving practice
 If the transmission repeatedly shifts up and down between
fourth and overdrive gears when climbing a gentle slope,
shift the selector lever to the “4” position. Be sure to shift the
selector lever to the “D” position after climbing the slope.
 When towing a trailer, in order to maintain efficient engine
braking and electrical charging performance, do not use
overdrive. The selector lever must be in the “4” position.
CAUTION
Always keep your foot on the brake pedal while stopped
with the engine running. This prevents the vehicle from
creeping.
NOTICE
Always use the brake pedal or the parking brake to hold
the vehicle on an upgrade. Do not attempt to hold the
vehicle using the accelerator pedal, as this can cause
the transmission to overheat.

STARTING AND DRIVING
315
(g) If you cannot shift the selector lever
If you cannot shift the selector lever even though the brake
pedal is depressed, use the shift lock override button. For
instructions, see “If you cannot shift automatic transmission
selector lever” on page 423.
ELECTRONIC THROTTLECONTROL SYSTEM
The electronic throttle control system always maintains
appropriate engine output in relation to the accelerator
opening in all driving conditions.
31L322
 1Power position 2Normal position
3Snow position
The electronic throttle control system has 3 modes:
Normal, Power and Snow modes.
Normal mode: For ordinary driving, Lexus recommends that
you use the normal mode to improve fuel economy.
Power mode: For more powerful acceleration and sporty
driving.

STARTING AND DRIVING
322The Lexus park assist system may detect the following by
mistake:

Bumpy roads or gravelled roads or grass when driving on
such surfaces, or on grass
 Devices issuing ultrasonic waves, such as a horn from
another vehicle, motorcycle engine, air braking sound from
heavy−duty vehicles, if such a device is operated around
your vehicle
 Rain or water splashing over the sensor
 The ground on which the vehicle is tilted
 Radio antenna or fender pole mounted on your vehicle
 Mud, ice or snowflakes on the sensor
 Tall curb stone
 Towing eyelet mounted on your vehicle
 Towing hitch mounted on your vehicle The Lexus park assist system may not detect the
following:

Thin objects such as wire or rope
 Objects with a surface area too small to reflect ultrasonic
waves such as wire gauze or fence
 Sound wave absorbing objects such as cotton or snow
 Objects with a sharp edge
 Shorter objects
 Tall objects with the upper part projected
For vehicles with a Navigation System, the park assist
graphics appear both on the navigation display and
multi− information display. For details, see the separate
“Navigation System Owner’s Manual”.
For vehicles sold in Canada
This ISM device complies with Canadian ICES −001.

STARTING AND DRIVING
326
31L357
Check surroundings for safety.
If a bright light (for example, sunlight reflected off the vehicle
body) is picked up by the camera, the smear effect* peculiar
to the camera may occur.
*: Smear effect — A phenomenon that occurs when a bright
light (for example, sunlight reflected off the vehicle body) is
picked up by the camera; when transmitted by the camera, the
light source appears to have a vertical streak above and below
it.
CRUISE CONTROL
The cruise control allows you to cruise the vehicle at a
desired speed over about 40 km/h (25 mph) with your foot
off the accelerator pedal.
Your cruising speed can be maintained although a slight speed
change may occur when driving up or down a gradient, within
the limits of engine performance. On steeper hills, a great
speed change will occur so it is better to drive without the cruise
control.
When the cruise control is on, the driving pattern of the
automatic transmission is fixed in the normal position,
regardless of the position of the selector switch.
CAUTION
 To help maintain maximum control of your vehicle,
do not use the cruise control when driving in heavy
or varying traffic, or on slippery (rainy, icy or
snowcovered) or winding roads.
 Avoid vehicle speed increases when driving
downhill. If the vehicle speed is too fast in relation to
the cruise control set speed, cancel the cruise
control then downshift the transmission to use
engine braking to slow down.

STARTING AND DRIVING
328
2Cancelling the preset speed
You can cancel the preset speed by either of the following:
a. Pulling the control lever in the “CANCEL” direction.
b. Depressing the brake pedal.
c. Pushing the “ON −OFF” button.
If the vehicle speed falls below about 40 km/h (25 mph), the
preset speed will be automatically cancelled.
If the vehicle speed drops 16 km/h (10 mph) below the preset
speed, the preset speed will also automatically be cancelled.
If the slip indicator light blinks and a warning tone sounds, the
preset speed will be automatically cancelled.
If the preset speed automatically cancels out for other than the
above reasons, do not operate the cruise control. Although it
is no problem to continue driving, have your vehicle checked
by your Lexus dealer at the earliest opportunity.
3 Resetting to a faster speed
Press the control lever upward in the “+ RES” direction and
hold it. Release the lever when the desired speed is attained.
While the lever is held upward, the vehicle will gradually gain
speed.
When the difference between the actual vehicle speed and the
set speed is less than 5 km/h (3 mph), the set speed can be
increased 1. 6 km/h (1 mph) each time by pressing the control
lever upward in the “+ RES” direction quickly within 0.6
seconds. However, a quicker way to reset is to accelerate the vehicle
and then press the control lever downward in the “– SET”
direction.
4
Resetting to a slower speed
Press the co ntrol lever downward in the “– SET” direction and
hold it. Release the lever when the desired speed is attained.
While the lever is held downward, the vehicle speed will
gradually decrease.
When the difference between the actual vehicle speed and the
set speed is less than 5 km/h (3 mph), the set speed can be
lowered 1.6 km/h (1 mph) each time by pressing the control
lever downward in the “– SET” direction quickly within 0.6
seconds.
However, a quicker way to reset is to depress the brake pedal
and then press the control lever downward in the “– SET”
direction.
With the cruise control on, even if you downshift the
transmission from the “D” position or “6” (sixth range) to the “5”\
(fifth range), or from the “D” position or “5” (fifth ran\
ge) to the
“4” (fourth range), engine braking will not be enabled because
the cruise control is not cancelled. To decrease the vehicle
speed, reset to a slower speed with the cruise control lever or
depress the brake pedal. If you use the brake pedal, cruise
control is cancelled.