2021 FORD EXPLORER cooling

GENERAL INFORMATION -
HYBRID ELECTRIC VEHICLE
(HEV)
WARNING: This battery pack
should only be serviced by an authorized
electric vehicle technician. Improper
handling can result in personal injury or
death. WARNING:
Apply the parking
brake, shift into park (P), switch the
ignition off and remove the key before
you open the hood or have any service
or repair work completed. If you do not
switch the ignition off, the engine could
restart at any time. Failure to follow this
instruction could result in personal injury
or death. WARNING:
Do not touch the
electronic ignition system parts after you
have switched the ignition on or when
the engine is running. The system
operates at high voltage. Failure to
adhere to this warning could result in
serious personal injury or death. WARNING:
Keep your hands and
clothing clear of the engine cooling fan.
Your vehicle consists of various
high-voltage components and wiring. All
of the high-voltage power flows through
specific wiring assemblies labeled as such
or covered with a solid orange convolute,
or orange striped tape, or both. Do not
come in contact with these components. The high-voltage battery system is a
high-voltage, lithium-ion battery system.
The pack is located underneath the vehicle.
The high voltage battery system uses an
advanced active liquid heating and cooling
system to regulate high voltage battery
temperature and help maximize the life of
the high voltage battery.
Note:
The high-voltage battery does not
require regular service maintenance.
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Explorer (CTW), enUSA, Edition date: 202007, Second-Printing High Voltage Battery
(If Equipped)

WHAT IS HILL DESCENT
CONTROL
WARNING: Hill descent control
cannot control descent in all surface
conditions and circumstances, such as
ice or extremely steep grades. Hill
descent control is a driver assist system
and cannot substitute for good judgment
by the driver. Failure to do so may result
in loss of vehicle control, crash or serious
injury. WARNING:
The system does not
replace the parking brake. When you
leave your vehicle, always apply the
parking brake and shift the transmission
into park (P) for automatic transmission
or first gear for manual transmission.
Note: The system does not function below
3 mph (5 km/h)
.
Hill descent control allows the driver to set
and maintain vehicle speed while
descending steep slopes in various surface
conditions.
The system can maintain vehicle speeds
on downhill slopes between
3– 20 mph
(5– 32 km/h). Above 20 mph (32 km/h),
the system remains on but the descent
speed cannot be set or maintained.
The system requires a cool down interval
after a period of sustained use. The
amount of time that the system can
remain active before cooling varies with
conditions. The system provides a warning
in the message center and a tone sounds
when the system is about to disengage for
cooling. At this time, manually apply the
brakes as needed to maintain descent
speed. SWITCHING HILL DESCENT
CONTROL ON AND OFF Press the button on the center
console. A light illuminates in the
control and a tone sounds when
the system is active.
SETTING THE HILL DESCENT
SPEED WARNING:
The system does not
replace the parking brake. When you
leave your vehicle, always apply the
parking brake and shift the transmission
into park (P) for automatic transmission
or first gear for manual transmission. WARNING:
The system does not
control speed in low traction conditions
or extremely steep slopes. The system
is designed to be an aid and does not
relieve you of your responsibility to drive
with due care and attention. Failure to
follow this instruction could result in
personal injury.
To increase the descent speed, press the
accelerator pedal until you reach the speed
you prefer.
To decrease the descent speed, press the
brake pedal until you reach the speed you
prefer.
When you reach the speed you prefer,
either by accelerating or decelerating,
remove your feet from the pedals. The
system maintains the chosen vehicle
speed.
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Explorer (CTW), enUSA, Edition date: 202007, Second-Printing Hill Descent Control
(If Equipped)

Before Towing a Trailer
Practice turning, stopping and backing up
to get the feel of your vehicle-trailer
combination before starting on a trip.
When turning, make wider turns so the
trailer wheels clear curbs and other
obstacles.
When Towing a Trailer
•
Do not drive faster than 70 mph
(113 km/h) during the first 500 mi
(800 km).
• Do not make full-throttle starts.
• Check your hitch, electrical connections
and trailer wheel lug nuts thoroughly
after you have traveled 50 mi (80 km).
• When stopped in congested or heavy
traffic during hot weather, place the
gearshift in park (P) to aid engine and
transmission cooling and to help A/C
performance.
• Turn off the speed control with heavy
loads or in hilly terrain. The speed
control may turn off automatically
when you are towing on long, steep
grades.
• Shift to a lower gear when driving down
a long or steep hill. Do not apply the
brakes continuously, as they may
overheat and become less effective.
• If your transmission is equipped with a
Grade Assist or Tow/Haul feature, use
this feature when towing. This provides
engine braking and helps eliminate
excessive transmission shifting for
optimum fuel economy and
transmission cooling.
• Allow more distance for stopping with
a trailer attached. Anticipate stops and
brake gradually.
• Avoid parking on a grade. However, if
you must park on a grade:
1. Turn the steering wheel to point your vehicle tires away from traffic flow. 2. Set your vehicle parking brake.
3. Place the automatic transmission in
park (P).
4. Place wheel chocks in front and back of the trailer wheels. (Chocks not
included with vehicle.)
Launching or Retrieving a Boat or
Personal Watercraft (PWC)
Note: Disconnect the wiring to the trailer
before backing the trailer into the water.
Note: Reconnect the wiring to the trailer
after
removing the trailer from the water.
When backing down a ramp during boat
launching or retrieval:
• Do not allow the static water level to
rise above the bottom edge of the rear
bumper.
• Do not allow waves to break higher
than
6 in (15 cm) above the bottom
edge of the rear bumper.
Exceeding these limits may allow water to
enter vehicle components:
• Causing internal damage to the
components.
• Affecting driveability, emissions, and
reliability.
Replace the rear axle lubricant anytime
the rear axle has been submerged in water.
Water may have contaminated the rear
axle lubricant, which is not normally
checked or changed unless a leak is
suspected or other axle repair is required.
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Explorer (CTW), enUSA, Edition date: 202007, Second-Printing Towing

REDUCED ENGINE
PERFORMANCE
WARNING: If you continue to drive
your vehicle when the engine is
overheating, the engine could stop
without warning. Failure to follow this
instruction could result in the loss of
control of your vehicle.
If the engine coolant temperature gauge
needle moves to the upper limit position,
the engine is overheating. See Gauges
(page 106).
You must only drive your vehicle for a short
distance if the engine overheats. The
distance you can travel depends on
ambient temperature, vehicle load and
terrain. The engine continues to operate
with limited power for a short period of
time.
If the engine temperature continues to rise,
the fuel supply to the engine reduces. The
air conditioning switches off and the engine
cooling fan operates continually.
1. Gradually reduce your speed and stop your vehicle as soon as it is safe to do
so.
2. Immediately switch the engine off to prevent severe engine damage.
3. Wait for the engine to cool down.
4. Check the coolant level. See
Engine
Coolant Check (page 331).
5. Have your vehicle checked as soon as possible.
ECONOMICAL DRIVING
Fuel economy is affected by several things
such as how you drive, the conditions you
drive under and how you maintain your
vehicle. You may improve your fuel economy by
keeping these things in mind:
•
Accelerate and slow down in a smooth,
moderate fashion.
• Drive at steady speeds.
• Anticipate stops; slowing down may
eliminate the need to stop.
• Combine errands and minimize
stop-and-go driving.
• Close the windows for high-speed
driving.
• Drive at reasonable speeds (traveling
at
55 mph (88 km/h) uses 15% less
fuel than traveling at 65 mph
(105 km/h)).
• Keep the tires properly inflated and use
only the recommended size.
• Use the recommended engine oil.
• Perform all regularly scheduled
maintenance.
Avoid these actions; they reduce your fuel
economy:
• Sudden accelerations or hard
accelerations.
• Revving the engine before switching it
off.
• Idle for periods longer than one minute.
• Warm up your vehicle on cold
mornings.
• Use the air conditioner or front
defroster.
• Use the speed control in hilly terrain.
• Rest your foot on the brake pedal while
driving.
• Drive a heavily loaded vehicle or tow a
trailer.
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Explorer (CTW), enUSA, Edition date: 202007, Second-Printing Driving Hints

Protected Component
Fuse Rating
Fuse or Relay
Number
Body control module - battery power in
feed 1.
40A
1
Power outlet main console bin.
20A
2
Body control module - battery power in
feed 2.
40A
3
Fuel pump.
30A
4
Powertrain control module keep alive
power.
5A
5
Powertrain control module power.
20A
6
Canister vent solenoid.
20A
7
Evaporative leak control module.
Exhaust gas heat recovery (hybrid electric
vehicle).
Tank pressure control valve (hybrid electric
vehicle).
Refueling valve (plug-in hybrid electric
vehicle).
Vapor blocking valve.
Universal exhaust gas oxygen 11.
Universal exhaust gas oxygen 21.
Catalyst monitor sensor 12.
Catalyst monitor sensor 22.
Canister purge valve.
Cooling fan relay coil.
20A
8
Battery interrupt box.
Transmission oil pump.
Auxiliary coolant pump.
Fuel flap door (hybrid electric vehicle).
Engine coolant bypass valve.
Active grille shutters.
Ignition coils.
20A
9
Front blower motor relay.
40A
13
Transmission oil pump.
15A
14
A/C compressor variable clutch.
Auxiliary pumps (hybrid electric vehicle).
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Explorer (CTW), enUSA, Edition date: 202007, Second-Printing Fuses

8. Install the air filter housing cover.
9. Engage the clips to secure the air filter
housing cover to the air filter housing.
10. Reconnect the boot to the air filter housing cover and torque to 3.69 lb.ft
(5 Nm).
ENGINE COOLANT CHECK WARNING:
Do not remove the
coolant reservoir cap when the engine is
on or the cooling system is hot. Wait 10
minutes for the cooling system to cool
down. Cover the coolant reservoir cap
with a thick cloth to prevent the
possibility of scalding and slowly remove
the cap. Failure to follow this instruction
could result in personal injury. WARNING:
Do not put coolant in
the windshield washer reservoir. If
sprayed on the windshield, coolant could
make it difficult to see through the
windshield. WARNING:
To reduce the risk of
personal injury, make sure the engine is
cool before unscrewing the coolant
pressure relief cap. The cooling system
is under pressure. Steam and hot liquid
can come out forcefully when you loosen
the cap slightly. WARNING:
Do not add coolant
further than the MAX mark.
When the engine is cold, check the
concentration and level of the coolant at
the intervals listed in the scheduled
maintenance information. See Scheduled
Maintenance
(page 482).
Note: Make sure that the coolant level is
between the
MIN and the MAX marks on
the coolant reservoir. Note:
Coolant expands when it is hot. The
level may extend beyond the
MAX mark.
Maintain coolant concentration within
48% to 50%, which equates to a freeze
point between
-29°F (-34°C) and -35°F
(-37°C). Coolant concentration should be
checked using a refractometer. We do not
recommend the use of hydrometers or
coolant test strips for measuring coolant
concentration.
Adding Coolant WARNING:
Do not add engine
coolant when the engine is on or the
cooling system is hot. Failure to follow
this instruction could result in personal
injury. WARNING:
Do not remove the
coolant reservoir cap when the engine is
on or the cooling system is hot. Wait 10
minutes for the cooling system to cool
down. Cover the coolant reservoir cap
with a thick cloth to prevent the
possibility of scalding and slowly remove
the cap. Failure to follow this instruction
could result in personal injury. WARNING:
Do not put coolant in
the windshield washer reservoir. If
sprayed on the windshield, coolant could
make it difficult to see through the
windshield.
Note: Do not use stop leak pellets, cooling
system sealants, or non-specified additives
as they can cause damage to the engine
cooling or heating systems. Resulting
component damage may not be covered by
the vehicle Warranty.
Note: Automotive fluids are not
interchangeable.
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Explorer (CTW), enUSA, Edition date: 202007, Second-Printing Maintenance

It is very important to use prediluted
coolant approved to the correct
specification in order to avoid plugging the
small passageways in the engine cooling
system. See Capacities and
Specifications (page 391). Do not mix
different colors or types of coolant in your
vehicle. Mixing of engine coolants or using
an incorrect coolant may harm the engine
or cooling system components and may
not be covered by the vehicle Warranty.
Note: If prediluted coolant is not available,
use the approved concentrated coolant
diluting it to 50/50 with distilled water. See
Capacities and Specifications (page 391).
Using water that has not been deionised
may contribute to deposit formation,
corrosion and plugging of the small cooling
system passageways.
Note: Coolants marketed for all makes and
models may not be approved to our
specifications and may cause damage to
the cooling system. Resulting component
damage may not be covered by the vehicle
Warranty.
If the coolant level is at or below the
minimum mark, add prediluted coolant
immediately.
To top up the coolant level do the
following:
1. Unscrew the cap slowly. Any pressure escapes as you unscrew the cap.
2. Add prediluted coolant approved to the correct specification. See
Capacities and Specifications (page
391
).
3. Add enough prediluted coolant to reach the correct level.
4. Replace the coolant reservoir cap. Turn
the cap clockwise until it contacts the
hard stop. 5. Check the coolant level in the coolant
reservoir the next few times you drive
your vehicle. If necessary, add enough
prediluted engine coolant to bring the
coolant level to the correct level.
If you have to add more than
1.1 qt (1 L) of
engine coolant per month, have your
vehicle checked as soon as possible.
Operating an engine with a low level of
coolant can result in engine overheating
and possible engine damage.
In case of emergency, you can add a large
amount of water without engine coolant
in order to reach a vehicle service location.
In this instance, qualified personnel:
1. Must drain the cooling system.
2. Chemically clean the coolant system.
3. Refill with engine coolant as soon as possible.
Water alone, without engine coolant, can
cause engine damage from corrosion,
overheating or freezing.
Do not use the following as a coolant
substitute:
• Alcohol.
• Methanol.
• Brine.
• Any coolant mixed with alcohol or
methanol antifreeze.
Alcohol and other liquids can cause engine
damage from overheating or freezing.
Do not add extra inhibitors or additives to
the coolant. These can be harmful and
compromise the corrosion protection of
the coolant.
Recycled Coolant
We do not recommend the use of recycled
coolant as an approved recycling process
is not yet available.
Note: Dispose of used coolant in the
appropriate manner.
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Explorer (CTW), enUSA, Edition date: 202007, Second-Printing Maintenance

Follow your community's regulations and
standards for recycling and disposing of
automotive fluids.
Severe Climates
If you drive in extremely cold climates:
•
It may be necessary to increase the
coolant concentration above 50%.
• A coolant concentration of 60%
provides improved freeze point
protection.
• Coolant concentrations above 60%
decrease the overheat protection
characteristics of the coolant and may
cause engine damage.
If you drive in extremely hot climates:
• You can decrease the coolant
concentration to 40%.
• A coolant concentration of 40%
provides improved overheat protection.
• Coolant concentrations below 40%
decrease the overheat and corrosion
protection characteristics of the
coolant and may cause engine
damage.
Vehicles driven year-round in non-extreme
climates should use prediluted coolant for
optimum cooling system and engine
protection.
Coolant Change
At specific mileage intervals, as listed in
the scheduled maintenance information,
the coolant should be changed. Add
prediluted coolant approved to the correct
specification. See Capacities and
Specifications (page 391). Fail-Safe Cooling
Fail-safe cooling allows you to temporarily
drive your vehicle before any incremental
component damage occurs. The fail-safe
distance depends on ambient
temperature, vehicle load and terrain.
How Fail-Safe Cooling Works If the engine begins to overheat,
the coolant temperature gauge
moves toward the red zone:
A warning lamp illuminates and
a message may appear in the
information display.
If the engine reaches a preset
over-temperature condition, the engine
automatically switches to alternating
cylinder operation. Each disabled cylinder
acts as an air pump and cools the engine.
When this occurs, your vehicle still
operates, however:
• Engine power is limited.
• The air conditioning system turns off.
Continued operation increases the engine
temperature, causing the engine to
completely shut down. Your steering and
braking effort increases in this situation.
When the engine temperature cools, you
can re-start the engine. Have your vehicle
checked as soon as possible to minimize
engine damage.
When Fail-Safe Mode Is Activated WARNING: Fail-safe mode is for
use during emergencies only. Operate
your vehicle in fail-safe mode only as
long as necessary to bring your vehicle
to rest in a safe location and seek
immediate repairs. When in fail-safe
mode, your vehicle will have limited
power, will not be able to maintain
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Explorer (CTW), enUSA, Edition date: 202007, Second-Printing Maintenance