Page 499 of 712

4997-3. Do-it-yourself maintenance
7
Maintenance and care
HIGHLANDER_U (OM48A12U)
WARNING
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 and 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.
■ When working near the electric co oling fans or radiator grille
Vehicles without a smart key system:
Be sure the engine switch is off.
With the engine switch in the “ON” position, the electric cooling fans may
automatically start to run if the air conditioning is on and/or the coolant tem-
perature is high. ( P. 509)
Vehicles with a smart key system:
Be sure the engine switch is off.
With the engine switch in IGNITION ON mode, the electric cooling fans may
automatically start to run if the air conditioning is on and/or the coolant tem-
perature is high. ( P. 509)
■ Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc.
from getting in your eyes.
NOTICE
■ If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear
due to dirt in the air.
Page 503 of 712
5037-3. Do-it-yourself maintenance
7
Maintenance and care
HIGHLANDER_U (OM48A12U)■
2.7 L 4-cylinder (1AR-FE) engine
Engine compar tment
Washer fluid tank
(P. 514)
Fuse boxes ( P. 535)
Engine oil level dipstick (P. 505)
Engine oil filler cap (P. 506)
Engine coolant reservoir (P. 508) Battery (
P. 5 1 1 )
Brake fluid reservoir (P. 510)
Electric cooling fans
Condenser ( P. 509)
Radiator ( P. 509)1
2
3
4
5
6
7
8
9
10
Page 504 of 712
5047-3. Do-it-yourself maintenance
HIGHLANDER_U (OM48A12U)■
3.5 L V6 (2GR-FE) engine
Washer fluid tank
(P. 514)
Fuse boxes ( P. 535)
Engine oil filler cap (P. 506)
Engine oil level dipstick (P. 505)
Engine coolant reservoir (P. 508) Battery (
P. 5 1 1 )
Brake fluid reservoir (P. 510)
Electric cooling fans
Condenser ( P. 509)
Radiator ( P. 509)1
2
3
4
5
6
7
8
9
10
Page 511 of 712
5117-3. Do-it-yourself maintenance
7
Maintenance and care
HIGHLANDER_U (OM48A12U)
Check the battery as follows:
■Battery exterior
Make sure that the battery terminals are not corroded and that
there are no loose connections, cracks, or loose clamps.Terminals
Hold-down clamp
■Before recharging
When recharging, the battery produces hydrogen gas which is flammable and
explosive. Therefore, observe the following before recharging:
● If recharging with the battery install ed on the vehicle, be sure to disconnect
the ground cable.
● Make sure the power switch on the charger is off when connecting and dis-
connecting the charger cables to the battery.
Battery
1
2
Page 512 of 712

5127-3. Do-it-yourself maintenance
HIGHLANDER_U (OM48A12U)■
After recharging/reconnecting the battery (vehicles with a smart key sys-
tem)
The engine may not start. Follow the procedure below to initialize the system.
Shift the shift lever to P.
Open and close any of the doors.
Restart the engine.
● Unlocking the doors using the smart key system may not be possible imme-
diately after reconnecting the battery. If this happens, use the wireless
remote control or the mechanical key to lock/unlock the doors.
● Start the engine with the engine switch in ACCESSORY mode. The engine
may not start with the engine switch turned off. However, the engine will
operate normally from the second attempt.
● The engine switch mode is recorded by the vehicle. If the battery is discon-
nected and reconnected, the vehicle will return the engine switch mode to
the status it was in before the battery was disconnected. Make sure to turn
off the engine before disconnecting the battery. Take extra care when con-
necting the battery if the engine switch mode prior to the battery being dis-
connected is unknown.
If the system will not start even after multiple attempts, contact your Toyota
dealer.
WARNING
■ Chemicals in the battery
Batteries contain poisonous and corrosive sulfuric acid and may produce
hydrogen gas which is flammable and explosive. To reduce the risk of death
or serious injury, take the following precautions while working on or near the
battery:
●Do not cause sparks by touching the battery terminals with tools.
● Do not smoke or light a match near the battery.
● Avoid contact with eyes, skin and clothes.
● Never inhale or swallow electrolyte.
● Wear protective safety glasses when working near the battery.
● Keep children away from the battery.
1
2
3
Page 513 of 712

5137-3. Do-it-yourself maintenance
7
Maintenance and care
HIGHLANDER_U (OM48A12U)
WARNING
■Where to safely charge the battery
Always charge the battery in an open area. Do not charge the battery in a
garage or closed room where there is insufficient ventilation.
■ How to recharge the battery
Only perform a slow charge (5 A or less). The battery may explode if
charged at a quicker rate.
■ Emergency measures regarding electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immedi-
ate medical attention. If possible, continue to apply water with a sponge or
cloth while traveling to the nearest medical facility.
● If electrolyte gets on your skin
Wash the affected area thoroughly. If you feel pain or burning, get medical
attention immediately.
● If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the cloth-
ing and follow the procedure above if necessary.
● If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medical attention
immediately.
NOTICE
■When recharging the battery
Never recharge the battery while the engine is operating. Also, be sure all
accessories are turned off.
Page 532 of 712
5327-3. Do-it-yourself maintenance
HIGHLANDER_U (OM48A12U)
●Flathead screwdriver
● Small flathead screwdriver
● Lithium battery CR2016 (vehicles without a smart key system), or
CR2032 (vehicles with a smart key system)
Vehicles without a smart key system
Remove the cover.
To prevent damage to the key,
cover the tip of the flathead screw-
driver with a rag.
To prevent the buttons from being
disassembled, face the button sur-
face downward.
Remove the module.
Wireless remote control/electronic key
batter y
Replace the battery with a new one if it is depleted.
You will need the following items:
Replacing the battery
1
2
Page 533 of 712
5337-3. Do-it-yourself maintenance
7
Maintenance and care
HIGHLANDER_U (OM48A12U)
Open the case cover using a
coin protected with tape etc.
and remove the depleted bat-
tery using a small flathead
screwdriver.
Insert a new battery with the “+”
terminal facing up.
Vehicles with a smart key system
Take out the mechanical key.
Remove the cover.
To prevent damage to the key,
cover the tip of the flathead screw-
driver with a rag.
Remove the depleted battery.
Insert a new battery with the “+”
terminal facing up.
3
1
2
3