air condition TOYOTA TUNDRA 2021 (in English) Service Manual

4326-3. Do-it-yourself maintenance
■Situations in which the tire pressure warning system may not oper-
ate properly
●In the following cases, the tire pressure warning system may no t operate
properly.
• If non-genuine Toyota wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equip-
ment) tire.
• A tire has been replac ed with a tire that is not of the specif ied size.
• Tire chains, etc., are equipped.
• An auxiliary-supported ru n-flat tire is equipped.
• If a window tint that affects the radio wave signals is instal led.
• If there is a lot of snow or ice on the vehicle, particularly around the
wheels or wheel housings.
• If the tire inflation pressure is extremely higher than the sp ecified
level.
• If wheel without the tire pressure warning valve and tranmitter is used.
• If the ID code on the tire pressure warning valves and transmi tter is
not registered in the tire pressure warning computer.
●Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio stat ion, large
display, airport or other facilit y that generates strong radio waves or
electrical noise
• When carrying a portable radio, cellular phone, cordless phone or
other wireless communication device
If tire position information is not correctly displayed due to the radio
wave conditions, the display may be corrected by driving and ch anging
the radio wave conditions.
●When the vehicle is parked, the time taken for the warning to s tart or go
off could be extended.
●When tire inflation pressure declines rapidly for example when a tire has
burst, the warning may not function.

4416-3. Do-it-yourself maintenance
6
Maintenance and care
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves,
transmitters and tire valve caps
●When removing or fitting the wheels, tires or the tire pressure warning
valves and transmitters, contact your Toyota dealer as the tire pres-
sure warning valves and transmitters may be damaged if not hand led
correctly.
●Make sure to install the tire val ve caps. If the tire valve caps are not
installed, water could enter the tire pressure warning valves a nd the
tire pressure warning valves could be bound.
●When replacing tire valve caps, do not use tire valve caps othe r than
those specified. The cap may become stuck.
■To avoid damage to the tire pressure warning valves and transmi t-
ters
When a tire is repaired with liqui d sealants, the tire pressure warning
valve and transmitter may not operate properly. If a liquid sea lant is
used, contact your Toyota dealer or other qualified service shop as soon
as possible. Make sure to replac e the tire pressure warning valve and
transmitter when replacing the tire. ( P. 4 2 7 )
■Driving on rough roads
Take particular care when drivi ng on roads with loose surfaces or pot-
holes.
These conditions may cause losses in tire inflation pressure, reducing
the cushioning ability of the t ires. In addition, driving on ro ugh roads
may cause damage to the tires themselves, as well as the vehicl e’s
wheels and body.
■If tire inflation pressure of e ach tire becomes low while drivi ng
Do not continue driving, or your t ires and/or wheels may be ruined.

4446-3. Do-it-yourself maintenance
■Instructions for checking tire inflation pressure
When checking tire inflation pressure, observe the following:
●Check only when the tires are cold.
If your vehicle has been parked for at least 3 hours or has not been
driven for more than 1 mile or 1.5 km, you will get an accurate cold tire
inflation pressure reading.
●Always use a tire pressure gauge.
It is difficult to judge if a tire is properly inflated based o nly on its appear-
ance.
●It is normal for the tire inflation pressure to be higher after driving as
heat is generated in the tire. Do not reduce tire inflation pre ssure after
driving.
●Passengers and luggage weight should be placed so that the vehi cle is
balanced.
WARNING
■Proper inflation is critical to save tire performance
Keep your tires properly inflated.
If the tires are not properly in flated, the following conditions may occur
which could lead to an accident r esulting in death or serious injury:
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts resulting from overh eated tires
●Air leaking from between tire and wheel
●Wheel deformation and/or tire damage
●Greater possibility of tire damage while driving (due to road hazards,
expansion joints, sharp ed ges in the road, etc.)
NOTICE
■When inspecting and adjusti ng tire inflation pressure
Be sure to put the tire valve caps back on.
If a valve cap is not installed , dirt or moisture may get into the valve and
cause an air leak, resulting in decreased tire inflation pressu re.

4486-3. Do-it-yourself maintenance
Air conditioning filter
Turn the engine switch off.
Open the glove box.
Remove the tray.
Remove the cover by sliding up
while pulling toward you.
The air conditioning filter must be changed regularly to maintain
air conditioning efficiency.
Removal method
1
2
3
4

4496-3. Do-it-yourself maintenance
6
Maintenance and care
Remove the filter cover.
Pull the filter out of the filter out-
let.
Remove the air conditioning filter
and replace it with a new one.
The “UP” marks shown on the fil-
ter should be pointing up.
■ Checking interval
Inspect and replace the air conditioning filter according to th e maintenance
schedule. In dusty areas or areas with heavy traffic flow, earl y replacement
may be required. (For scheduled maintenance information, please refer to the
“Scheduled Maintenance Guide” or “Owner’s Manual Supplement”.)
■ If air flow from the ven ts decreases dramatically
The filter may be clogged. Check the filter and replace if nece ssary.
5
6
Replacement method

4506-3. Do-it-yourself maintenance
NOTICE
■When using the air conditioning system
Make sure that a filter is always installed.
Using the air conditioning system without a filter may cause da mage to the
system.

483
7
When trouble arises
7-2. Steps to take in an emergency
If you think something is wrong
●Fluid leaks un der the vehicle.
(Water dripping from the air conditioning a fter use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temperature gauge needle continually points high er
than normal.
● Voltmeter continually points higher or lower than normal
● Engine oil pressure gauge cont inually points lower than normal
● Automatic transmission fluid temperature warning message is dis -
played
● Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the engine
● Engine misses, stumbli ng or running roughly
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one s ide when driving on a level road
● Loss of brake effectiveness, spongy feeling, pedal almost touch es
the floor
If you notice any of the followi ng symptoms, your vehicle proba -
bly needs adjustment or repair. Contact your Toyota dealer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

4907-2. Steps to take in an emergency
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural caus es such
as natural air leaks and tire inflation pressure changes caused by tem-
perature. In this case, adjusting the tire inflation pressure w ill turn off the
warning light (after several minutes).
■When a tire is replace d with a spare tire
The temporary spare tire is not equipped with a tire pressure w arning
valve and transmitter. If a tire goes flat, the tire pressure w arning light will
not turn off even though the flat tire has been replaced with t he temporary
spare tire. Replace the temporary spare tire with the repaired tire and
adjust the tire inflation pressu re. The tire pressure warning l ight will go off
after several minutes.
■Conditions that the tire pressure warning system may not functi on
properly
 P. 4 3 2
■If the tire pressure warning light frequently comes on after bl inking
for 1 minute
If the tire pressure warning light frequently comes on after bl inking for 1
minute when the engine switch is turned to ON, have it checked by your
Toyota dealer.
■ Warning buzzer
In some cases, the buzzer may not be heard because of noisy pla ce or an
audio sound.

529
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge ( P. 1 0 5 )
enters the red zone or a loss of engine power is experienced. ( For
example, the vehicle speed does not increase.)
● “ENGINE COOLANT OVERTEMP” is shown on the multi-informa-
tion display.
● Steam comes out f rom under the hood.
Stop the vehicle in a safe place and turn off the air condition ing sys-
tem, and then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled
down sufficiently, inspect the
hoses and radiator core (radia-
tor) for any leaks. Radiator
Cooling fan
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
The following may indicate that your vehicle is overheating:
Correction procedures
1
2
3
1
2

5598-1. Specifications
8
Vehicle specifications
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pres-
sure
Tire pressure when the vehicle has been
parked for three hours or more, or has not
been driven more than 1 mile or 1.5 km under
that condition
Maximum inflation
pressureThe maximum cold inflated pressure to which
a tire may be inflated, shown on the sidewall
of the tire
Recommended infla-
tion pressureCold tire inflation pressure recommended by a
manufacturer
Accessory weight
The combined weight (in excess of those stan-
dard items which may be replaced) of auto-
matic transmission, power steering, power
brakes, power windows, power seats, radio
and heater, to the extent that these items are
available as factory-installed equipment
(whether installed or not)
Curb weight
The weight of a motor vehicle with standard
equipment, including the maximum capacity of
fuel, oil and coolant, and if so equipped, air
conditioning and additional weight optional
engine
Maximum loaded vehi-
cle weight
The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant
weight150 lb. (68 kg) times the number of occupants
specified in the second column of Table 1
*
that follows
Occupant distributionDistribution of occupants in a vehicle as speci-
fied in the third column of Table 1
* below
Production options
weight
The combined weight of installed regular pro-
duction options weighing over 5 lb. (2.3 kg) in
excess of the standard items which they
replace, not previously considered in curb
weight or accessory weight, including heavy
duty brakes, ride levelers, roof rack, heavy
duty battery, and special trim