2010 Lexus GX460 engine

5
When trouble arises
735
5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
Emergency start function
When the engine does not start, the following steps can be used as an
interim measure to start the engine if the “ENGINE START STOP” switch
is functioning normally:
Set the parking brake.
Shift the shift lever to P.
Turn the “ENGINE START STOP” switch to ACCESSORY
mode.
Press and hold the “ENGINE START STOP” switch for about 15
seconds while depressing the brake pedal firmly.
Even if the engine can be started using the above steps, the system may
be malfunctioning. Have the vehicle inspected by your Lexus dealer.
■ The starter motor does not turn over, interior lights and headlights
do not turn on, or the horn does not sound
One of the following may be the cause of the problem:
●One or both of the battery terminals may be disconnected.
● The battery may be discharged. ( P. 74 1 )
● There may be a malfunction in the steering lock system.
Contact your Lexus dealer if the problem cannot be repaired, or if
repair procedures are unknown.
STEP1
STEP2
STEP3
STEP4

736
5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
If the shift lever cannot be shifted from P
If the shift lever cannot be shifted with your foot on the brake, there may be
a problem with the shift lock system (a system to prevent accidental opera-
tion of the shift lever). Have the vehicle inspected by your Lexus dealer
immediately. 
The following steps may be used as an emergency measure to ensure that
the shift lever can be shifted:
Set the parking brake.
Turn the “ENGINE START STOP” switch to ACCESSORY
mode.
Depress the brake pedal.
Pry the cover up with a flathead
screwdriver or tool.
Press the shift lock override but-
ton.
The shift lever can be shifted
while the button is pressed.
STEP1
STEP2
STEP3
STEP4
STEP5

738
5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
If the electronic key does not operate properly
Locking and unlocking the doors and key linked functions
Use the mechanical key (P. 2 6 )
in order to perform the following
operations (driver’s door only):
Locks all the doors
Closes the windows and moon
roof (turn and hold)
*
Unlocks the door
Turning the key rearward unlocks
the driver’s door. Turning the key
once again unlocks the other
doors.
Opens the windows and moon
roof (turn and hold)
*
*
: This setting must be customized at your Lexus dealer.
If communication between the electron ic key and vehicle is interrupted
(  P. 40) or the electronic key cannot be used because the battery is
depleted, the smart access system with push-button start and wireless
remote control cannot be used. In such cases, the doors can be opened or
the engine can be started by following the procedure below.

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When trouble arises
739
5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
Changing “ENGINE START STOP” switch modes and starting the engine
Ensure that the shift lever is in P and depress the brake pedal.Touch the Lexus emblem side of
the electronic key to the
“ENGINE START STOP” switch.
If any of the doors is opened or
closed while the key is being
touched to the switch, an alarm will
sound to indicate that the start
function cannot detect the elec-
tronic key.
To change “ENGINE START STOP” switch modes: Within 10
seconds of the buzzer sounding , release the brake pedal and
press the “ENGINE START STOP” switch. Modes can be
changed each time the switch is pressed. ( P. 1 8 1 )
To start the engine: Press th e “ENGINE START STOP” switch
within 10 seconds of the buzz er sounding, keeping the brake
pedal depressed.
In the event that the “ENGINE START STOP” switch still cannot be oper-
ated, contact your Lexus dealer.
STEP1
STEP2
STEP3

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5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
■Stopping the engine
Shift the shift lever to P and press the “ENGINE START STOP” switch as you nor-
mally do when stopping the engine.
■Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the elec-
tronic key battery be replaced immediately when the battery is depleted. 
(  P. 6 4 2 )

5
When trouble arises
741
5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
If the vehicle battery is discharged
The following procedures may be used to start the engine if the vehicle’s
battery is discharged.
You can call your Lexus dealer, or qualified repair shop.
If you have a set of jumper (or booster) cables and a second vehicle
with a 12 volt battery, you can jump start your Lexus by following the
steps below.
Open the hood. ( P. 6 0 7 )
Connecting the jumper cables accord ing to the following procedure:
Positive (+) battery terminal on your vehicle.
Positive (+) battery terminal on the second vehicle.
Negative (-) battery terminal on the second vehicle.
Connect the jumper cable to ground on your vehicle as shown in the
illustration.
STEP1
STEP2

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5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
■Starting the engine when the battery is discharged
The engine cannot be started by push-starting.
■To prevent battery discharge
●Turn off the headlights and the audio system while the engine is off.
●Turn off any unnecessary electrical components when the vehicle is running at a
low speed for an extended period, such as in heavy traffic, etc.
Start the engine of the second vehicle. Increase the engine
speed slightly and maintain at that level for approximately 5
minutes to recharge the battery of your vehicle.
Open and close any of the doors of your vehicle with the
“ENGINE START STOP” switch off.
Maintain the engine sp eed of the second vehicle and start the
engine of your vehicle by tu rning the “ENGINE START STOP”
switch to IGNITION ON mode.
Once your vehicle’s engine has started, remove the jumper
cables in the exact reverse ord er in which they were con-
nected.
Once the engine starts, have the ve hicle checked at your Lexus dealer
as soon as possible.STEP3
STEP4
STEP5
STEP6

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5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
If your vehicle overheats
If the engine overheats:
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 engine. Carefully lift the hood after the steam sub-
sides and then restart the engine.
If you do not see steam: Leave the engine running and carefully lift the hood.
Remove the engine compartment covers. ( P. 6 0 9 )
Check to see if the cooling fan is operating.
If the fan is operating: 
Wait until the engine coolant temperature gauge begins to
fall and then stop the engine.
If the fan is not operating: 
Stop the engine and call your local Lexus dealer.STEP1
STEP2
STEP3
STEP4