2012 TOYOTA TUNDRA coolant temperature

189
2
When driving
2-2. Instrument cluster
Gauges and meters
Vehicles with multi-information display
The following gauges, meters and displays illuminate when the
engine switch is in the ON position. Tachometer
Displays the engine speed in revolutions per minute.
Speedometer
Displays the vehicle speed.
Fuel gauge
Displays the quantity of fuel remaining in the tank.
Vo l t m e t e r
Displays the charge state.
Engine oil pressure gauge
Displays the engine oil pressure.
Engine coolant temperature gauge
Displays the engine coolant temperature.
Odometer/trip meter switching and trip meter resetting button
Switches between odometer and trip meter displays. Pushing and hold-
ing the button will reset the trip meter when the trip meter is being dis-
played.

192 2-2. Instrument cluster
Fuel gauge
Displays the quantity of fuel remaining in the tank.
Voltmeter (if equipped)
Displays the charge state.
Engine oil pressure gauge (if equipped)
Displays the engine oil pressure.
Engine coolant temperature gauge
Displays the engine coolant temperature.
Odometer/trip meter switching and trip meter resetting button
Switches between odometer and trip meter displays. Pushing and hold-
ing the button will reset the trip meter when the trip meter is being dis-
played.
Odometer/trip meter
Odometer:
Displays the total distance the vehicle has been driven.
Trip meter:
Displays the distance the vehicle has been driven since the meter was
last reset. Trip meters A and B can be used to record and display differ-
ent distances independently.
Automatic transmission fluid temperature gauge (if equipped)
Displays the automatic transmission fluid temperature.

194 2-2. Instrument cluster
Instrument panel light controlThe brightness of the instrument panel lights can be adjusted.
Brighter
Darker
Vehicles with multi-information
display
With the dial turned fully up, the
intensity of the instrument panel
lights will not be reduced even
when the tail lights/headlights are
turned on.
NOTICE
■To prevent damage to the engine and its components
●Do not let the indicator needle of the tachometer enter the red zone, which
indicates the maximum engine speed.
● The engine may be overheating if the engine coolant temperature gauge is
in the red zone (H). In this case, immediately stop the vehicle in a safe
place, and check the engine after it has cooled completely. ( P. 651)
■ While driving
●When the voltmeter indicates more than 19 V or less than 9 V, the battery
may be malfunctioning. Have your vehicle checked at your Toyota dealer.
● When the engine oil pressure gauge does not work properly, immediately
stop the engine and contact your Toyota dealer.
● When the automatic transmission fluid temperature gauge needle continu-
ally points higher than normal, immediately contact your Toyota dealer. (if
equipped)

244 2-4. Using other driving systems
■If the 4LO indicator light blinks
●If the 4LO indicator continues to blink when shifting between 4H and 4L,
stop the vehicle completely, move the shift lever to N and operate the
switch again.
● If the shift lever is moved before the 4LO indicator turns on/off, the trans-
fer mode may not be shifted completely. The transfer mode disengages
both the front and rear driveshafts from the powertrain and allows the
vehicle to move regardless of the shift position. (At this time, the indicator
blinks and the buzzer sounds.)
Therefore, the vehicle is free to roll even if the automatic transmission is in
P. You or someone else could be seriously injured. You must complete the
shifting of the transfer mode.
To complete the shifting, stop the vehicle completely, return the shift lever
to N, and confirm that the shift was completed (The indicator turns on/off).
● If the engine coolant temperature is too low, the transfer mode may not
be able to be shifted. When the engine is warmer, operate the switch
again.
If the 4LO indicator light continues to blink even after attempting the above,
there may be a malfunction in the engine, the brake system or the four-
wheel drive system. In this case, you may not be able to shift between 4H
and 4L. Have the vehicle inspected by your Toyota dealer immediately.
■ Shifting to 4L
VSC is automatically turned off.
■ Four-wheel drive usage frequency
You should drive in four-wheel drive for at least 10 miles (16 km) each
month.
This will assure that the front drive components are lubricated.

288 2-5. Driving information
●To maintain engine braking efficiency and charging system perfor-
mance when using engine braking, do not use the transmission in
D.
Transmission shift range position must be in 4 in the S mode.
● Instability happens more frequently when descending steep or long
downhill grades. Before descending, slow down and downshift. Do
not make sudden downshifts while descending steep or long down-
hill grades.
● Avoid holding the brake pedal down too long or applying the
brakes too frequently. This could cause the brakes to overheat and
result in reduced braking efficiency.
● Due to the added load of the trailer, your vehicle’s engine may
overheat on hot days (at temper atures over 85°F [30°C]) when
driving up a long or steep grade. If the engine coolant temperature
gauge indicates overheating, immediately turn off the air condition-
ing (if in use), pull your vehicle off the road and stop in a safe spot.
(  P. 651)
● Always place wheel blocks under both the vehicle’s and the
trailer’s wheels when parking. Ap ply the parking brake firmly, and
put the transmission in P. Avoid parking on a slope, but if unavoid-
able, do so only after performing the following:
Apply the brakes and keep them applied.
Have someone place wheel blo cks under both the vehicle’s
and trailer’s wheels.
When the wheel blocks are in place, release the brakes slowly
until the blocks absorb the load.
Apply the parking brake firmly.
Shift into P and turn off the engine.

540 4-3. Do-it-yourself maintenance
CAUTION
The engine compartment contains many mechanisms and fluids that may
move suddenly, become hot, or become electrically energized. To avoid death
or serious injury observe the following precautions.
■When working on the engine compartment
●Keep hands, clothing, and tools away from the moving fan and engine
drive belt.
● Be careful not to touch the engine, radiator, exhaust manifold, etc. right
after driving as they may be hot. Oil and other fluids may also be hot.
● Do not leave anything that may burn easily, such as paper or rags, in the
engine compartment.
● Do not smoke, cause sparks or expose an open flame to fuel or the bat-
tery. Fuel and battery fumes are flammable.
● Be extremely cautious when working on the battery. It contains poisonous
and corrosive sulfuric acid.
● Take care because brake fluid can harm your hands or eyes and damage
painted surfaces.
If fluid gets on your hands or in your eyes, flush the affected area with
clean water immediately.
If you still experience discomfort, see a doctor.
■ When working near the cooling fan or radiator grille
Be sure the engine switch is off.
With the engine switch on, the cooling fan may automatically start to run if
the air conditioning is on and/or the coolant temperature is high.
■ Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from
getting in the eyes.

5
When trouble arises
607
5-1. Essential information
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact your Toyota dealer as soon as
possible.
■ Visible symptoms
●Fluid leaks under the vehicle
(Water dripping from the air cond itioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temperature g auge needle continually points
higher than normal
● Voltmeter continually points higher or lower than normal
(if equipped)
● Engine oil pressure gauge continually points lower than nor-
mal (if equipped)
● Automatic transmission fluid temperature gauge needle con-
tinually points higher than normal (if equipped)
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the engine
■ Operational symptoms
●Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, s pongy feeling, pedal almost
touches the floor

5
When trouble arises
619
5-2. Steps to take in an emergency
If a war ning message is displayed (vehicles with multi-infor mation display)
Stop the vehicle immediately.The following warnings indicate the possibility of damage to the vehi-
cle that may lead to an accident. Immediately stop the vehicle in a
safe place and contact your Toyota dealer.
Warning messageDetails
(Flashing) Indicates that the engine coolant temperature is
too high
A buzzer also sounds.
Indicates that the automatic transmission fluid
temperature is too high A buzzer also sounds.
If a warning is shown on the multi- information display, stay calm and
perform the following actions:
Master warning light
The master warning light also
comes on or flashes in order to
indicate that a message is cur-
rently being displayed on the
multi-information display.
Multi-information display
If any of the warning lights turns on again after performing the fol-
lowing actions, contact your Toyota dealer.