2007 Lexus GS450h engine

5
When trouble arises
431
5-2. Steps to take in an emergency
Stop the vehicle immediately.
The following warning indicates the possibility of damage to the vehicle
that may lead to an ac cident. Immediately stop the vehicle in a safe place
and contact your Lexus dealer.
Have the vehicle inspected by your Lexus dealer immediately.
Failing to investigate the cause of the following warnings may lead to the
system operating abnormally and possibly cause an accident. Have the
vehicle inspected by your Lexus dealer immediately.
Warning lightWarning light/Details
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
while the hybrid system is running.
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Malfunction indicator lampMalfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The transmission control system.
SRS warning light
Malfunction in:
• The SRS airbag system; or
• The seat belt pretensioner system.

5
When trouble arises
437
5-2. Steps to take in an emergency
Stop the vehicle immediately.
A buzzer sounds and a warning message is shown on the multi-informa -
tion display. The following warnings indicate the pos
sibility of damage to
the vehicle that may lead to an acci dent. Immediately stop the vehicle in a
safe place and contact your Lexus dealer.
Wa r n i n g m e s s a g eDetails
Malfunction in the hybrid system.
(Flashing)
Abnormal engine oil pressure.
The warning light may turn on if the engine oil pres-
sure is too low.

5
When trouble arises
445
5-2. Steps to take in an emergency
Wa r n i n g m e s s a g eDetailsCorrection procedure
The engine oil level is low.Check the engine oil level,
and add if necessary.
(U.S.A. only)
The engine oil is sched-
uled 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)
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).

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When trouble arises
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5-2. Steps to take in an emergency
Wa r n i n g m e s s a g eDetailsCorrection procedure
(Flashing)
(If equipped)
The radar cruise control
system is unable to judge
vehicle-to-vehicle dis-
tance.
• Switch the mode select to either the normal or
power mode.
• If the windshield wipers are on, turn them off or
set them to either the
intermittent or the slow
mode.
(Flashing)
(If equipped)
Yo u r v e h i c l e i s n e a r i n g
the vehicle ahead (in
radar cruise mode).Slow the vehicle by apply-
ing the brakes.
The vehicle is unable to
drive over 60 mph (or
120 km/h) until the trans-
mission warms up.
Wait until the transmission
warms up.
(Flashing)
The hybrid battery (trac-
tion battery) is low.Stop the vehicle and shift
the shift lever to “P”.
(Flashing)
The gasoline engine can-
not operate or the shift
lever is in “N” for a long
time.
Stop the vehicle and shift
the shift lever to “P”.

448
5-2. Steps to take in an emergency
Wa r n i n g m e s s a g eDetailsCorrection procedure
(Flashing)
The transmission is out of
“P” when attempting to
start the hybrid system.Shift the shift lever to “P”
before pressing the power
switch.
■After changing the engine oil (U.S.A. only)
Make sure to reset the oil maintenance data. (P.
3 6 6 )
■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

5
When trouble arises
471
5-2. Steps to take in an emergency
If the 12 volt battery is discharged
The following procedures may be used to start the hybrid system if the 12
volt battery is discharged.

You can call your Lexus dealer, Roadside Assistance or Lexus Customer
Ser
vice.
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 following the steps
below.
Open the trunk using the mechanical key. ( P. 4 6 9 )
Connecting the jumper cables. If required, remove all vent pl ugs fr
om the booster battery. Lay a
cloth over the open vents on the booster batter
y. (This helps reduce
the explosion hazard, personal injuries and burns.)
Positive (+) battery terminal on your vehicle.
Positive (+) battery terminal on the second vehicle.
Negative (-) battery terminal on the second v
ehicle.
Negative (-) battery terminal or your vehicle. Start the engine of the second v
ehicle. Increase the engine
speed slightly and maintain at that le
vel for approximately 5
minutes to recharge the 12 volt battery of your vehicle.
Open and close any of the door s with the po
wer switch “OFF”.
STEP1
STEP2
STEP3
STEP4

472
5-2. Steps to take in an emergency
■To prevent 12 volt battery discharge
●Turn off the headlights and the audio system while the hybrid system 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.
■When the 12 volt battery is removed or discharged
The hybrid system may not start. ( P. 3 7 2 )
Also, the following systems must be initialized.
●Po w e r w i n d o w s (P. 5 3 )
●Moon roof (P. 5 6)
●Variable gear ratio steering (P. 1 5 1 )
●Tire pressure warning system (P. 3 7 7 )
●Intuitive parking assist (P. 1 5 1)
Maintain the engine speed on th e second vehicle and turn the
power switch to the “IG-ON” mo de, then start the vehicle’s
hybrid system.
Make sure the “READY” light co mes on. If the light does not
come on, contact your Lexus dealer.
Once the vehicle’s hybrid system has started, remove the
jumper cables in the exact reverse or
der in which they were
connected.
Once the hybrid system starts, have the v
ehicle checked at your Lexus
dealer as soon as possible.
STEP5
STEP6
STEP7

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When trouble arises
475
5-2. Steps to take in an emergency
If your vehicle overheats
■Electric motor (traction motor) and inverter
If the message “HYBRID SYSTEM OVERHEAT” is displayed on the
multi-information display.
■ Ga
soline engine
If the needle of the engine co olant temper
ature gauge enters the
red zone, the gasoline engine has probably overheated.
Observe the following steps: Stop the vehicle in a safe place and turn of
f 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 and carefully lift the hood.
If you do not see steam: Leave the hybrid system running and carefully lift the hood.
Remove the engine compartment cover. ( P. 362 )
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 hybrid s
ystem.
If the fan is not operating: 
Stop the hybrid system immed iately and call y
our local
Lexus dealer.
After the hybrid system has
cooled do
wn sufficiently, check
the coolant level and inspect the
radiator core (radiator) for any
leaks.
STEP1
STEP2
STEP3
STEP4
STEP5