maintenance FORD MUSTANG 2021 Owner's Guide

high-speed operation, and may
completely shut down without warning,
potentially losing engine power, power
steering assist, and power brake assist,
which may increase the possibility of a
crash resulting in serious 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.
Your vehicle has limited engine power
when in the fail-safe mode, drive your
vehicle with caution. Your vehicle does not
maintain high-speed operation and the
engine may operate poorly.
Remember that the engine is capable of
automatically shutting down to prevent
engine damage. In this situation:
1. Pull off the road as soon as safely possible and switch the engine off.
2. If you are a member of a roadside assistance program, we recommend
that you contact your roadside
assistance service provider.
3. If this is not possible, wait for a short period of time for the engine to cool.
4. Check the coolant level. If the coolant level is at or below the minimum mark,
add prediluted coolant immediately.
5. When the engine temperature cools, you can re-start the engine. Have your
vehicle checked as soon as possible to
minimize engine damage.
Note: Driving your vehicle without repair
increases the chance of engine damage. Engine Coolant Temperature
Management
(If Equipped) WARNING:
To reduce the risk of
crash and injury, be prepared that the
vehicle speed may reduce and the
vehicle may not be able to accelerate
with full power until the coolant
temperature reduces.
If you tow a trailer with your vehicle, the
engine may temporarily reach a higher
temperature during severe operating
conditions, for example ascending a long
or steep grade in high ambient
temperatures.
At this time, you may notice the coolant
temperature gauge moves toward the red
zone and a message may appear in the
information display.
You may notice a reduction in vehicle
speed caused by reduced engine power in
order to manage the engine coolant
temperature. Your vehicle may enter this
mode if certain high-temperature and
high-load conditions take place. The
amount of speed reduction depends on
vehicle loading, grade and ambient
temperature. If this occurs, there is no
need to stop your vehicle. You can
continue to drive.
The air conditioning may automatically
turn on and off during severe operating
conditions to protect the engine from
overheating. When the coolant
temperature decreases to the normal
operating temperature, the air conditioning
turns on.
If the coolant temperature gauge moves
fully into the red zone, or if the coolant
temperature warning or service engine
soon messages appear in your information
display, do the following:
267
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Maintenance

1. Stop your vehicle as soon as it is safe
to do so. Fully apply the parking brake,
shift into park (P) or neutral (N).
2. Leave the engine running until the coolant temperature gauge needle
returns to the normal position. If the
temperature does not drop after
several minutes, follow the remaining
steps.
3. Switch the engine off and wait for it to
cool. Check the coolant level.
4. If the coolant level is at or below the minimum mark, add prediluted coolant
immediately.
5. If the coolant level is normal, restart the engine and continue.
MANUAL TRANSMISSION
FLUID CHECK - 6-SPEED
MANUAL TRANSMISSION –
3160
Note: Make sure the vehicle is on a level
surface.
1. Clean the filler plug. 2. Remove the filler plug.
3.
Start the engine and allow it to idle for
two minutes with the clutch engaged.
4. Add fluid through the filler hole.
5. The correct fluid fill level is 0.0–0.1 in
(0– 3 mm) below the bottom edge of
the filler hole.
6. Install the filler plug.
7. Tighten the filler plug until you feel a strong resistance.
Only use fluid that meets our
specifications. See
Capacities and
Specifications (page 335).
MANUAL TRANSMISSION
FLUID CHECK - 6-SPEED
MANUAL TRANSMISSION –
MT82
1. Clean the filler plug. The filler plug is on the right-hand side of the
transmission. 2. Remove the filler plug.
3. The correct fluid fill level is
0.0–0.1 in
(0– 3 mm) below the bottom edge of
the filler hole.
4. Add fluid through the filler hole.
5. Install the filler plug.
268
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing MaintenanceE215477 E174951

6. Tighten the filler plug until you feel a
strong resistance.
Only use fluid that meets Ford
specifications. See Capacities and
Specifications (page 335).
AUTOMATIC TRANSMISSION
FLUID CHECK
If required, have an authorized dealer check
and change the transmission fluid at the
correct service interval. See
Scheduled
Maintenance (page 441).
The automatic transmission does not have
a transmission fluid dipstick.
Refer to your scheduled maintenance
information for scheduled intervals for fluid
checks and changes. Your transmission
does not consume fluid. However, if the
transmission slips, shifts slowly or if you
notice a sign of leaking fluid, contact an
authorized dealer.
Do not use supplemental transmission
fluid additives, treatments or cleaning
agents. The use of these materials may
affect transmission operation and result
in damage to internal transmission
components.
BRAKE FLUID CHECK WARNING:
Do not use any fluid
other than the recommended brake fluid
as this will reduce brake efficiency. Use
of incorrect fluid could result in the loss
of vehicle control, serious personal injury
or death. WARNING:
Only use brake fluid
from a sealed container. Contamination
with dirt, water, petroleum products or
other materials may result in brake
system damage or failure. Failure to
adhere to this warning could result in the
loss of vehicle control, serious personal
injury or death. WARNING:
Do not allow the fluid
to touch your skin or eyes. If this
happens, rinse the affected areas
immediately with plenty of water and
contact your physician. WARNING:
The brake system
could be affected if the brake fluid level
is below the MIN mark or above the MAX
mark on the brake fluid reservoir. 1. Park your vehicle on a level surface.
2. Look at the brake fluid reservoir to see
where the brake fluid level is relative
to the
MIN and the MAX marks on the
reservoir.
269
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing MaintenanceE170684

Note:
If the brake fluid level is between the
MIN and the MAX marks on the reservoir, it
is acceptable.
Note: If the brake fluid level is below the
MIN
mark or above the MAX mark, have
your vehicle checked as soon as possible.
Note: To avoid fluid contamination, the
reservoir cap must remain in place and fully
tight, unless you are adding fluid.
Only use fluid that meets our
specifications. See
Capacities and
Specifications (page 335).
Brake Fluid Service Interval
Brake fluid absorbs water over time which
degrades the effectiveness of the brake
fluid. Change the brake fluid at the
specified intervals to prevent degraded
braking performance.
For detailed interval information, see
Scheduled Maintenance in your Owner's
Manual or your local maintenance guide.
CLUTCH FLUID CHECK -
MANUAL TRANSMISSION
The clutch and brake systems share the
same fluid reservoir. See
Brake Fluid
Check (page 269).
POWER STEERING FLUID
CHECK
Your vehicle is equipped with an electric
power steering (EPS) system. There is no
fluid reservoir to check or fill. CHANGING THE 12V BATTERY WARNING:
Batteries normally
produce explosive gases which can
cause personal injury. Therefore, do not
allow flames, sparks or lighted
substances to come near the battery.
When working near the battery, always
shield your face and protect your eyes.
Always provide correct ventilation. WARNING:
When lifting a
plastic-cased battery, excessive pressure
on the end walls could cause acid to flow
through the vent caps, resulting in
personal injury and damage to the
vehicle or battery. Lift the battery with a
battery carrier or with your hands on
opposite corners. WARNING:
Keep batteries out of
reach of children. Batteries contain
sulfuric acid. Avoid contact with skin,
eyes or clothing. Shield your eyes when
working near the battery to protect
against possible splashing of acid
solution. In case of acid contact with skin
or eyes, flush immediately with water for
a minimum of 15 minutes and get prompt
medical attention. If acid is swallowed,
call a physician immediately. WARNING:
Battery posts,
terminals and related accessories
contain lead and lead compounds,
chemicals known to the State of
California to cause cancer and
reproductive harm. Wash your hands
after handling
.
270
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Maintenance

WARNING: This vehicle may have
more than one battery. Removing the
battery cables from only one battery
does not disconnect your vehicle
electrical system. Make sure you
disconnect the battery cables from all
batteries when disconnecting power.
Failure to do so may cause serious
personal injury or property damage. WARNING:
For vehicles with
Auto-Start-Stop the battery requirement
is different. You must replace the battery
with one of exactly the same
specification.
The battery is in the engine compartment.
See
Under Hood Overview (page 258).
Your vehicle has a maintenance-free
battery. It does not require additional
water during service.
If the vehicle battery has a cover and vent
hose, make sure you correctly install it after
cleaning or replacing the battery.
For longer, trouble-free operation, keep the
top of the battery clean and dry and the
battery cables tightly fastened to the
battery terminals. If any corrosion is
present on the battery or terminals, remove
the cables from the terminals and clean
with a wire brush. You can neutralize the
acid with a solution of baking soda and
water.
We recommend that you disconnect the
negative battery cable terminal from the
battery if you plan to store your vehicle for
an extended period.
Note: If you only disconnect the negative
battery cable terminal, make sure it is
isolated or placed away from the battery
terminal to avoid unintended connection or
arcing. If you replace the battery make sure it
matches the electrical requirements of
your vehicle.
If you disconnect or replace the battery
and your vehicle has an automatic
transmission, it must relearn its adaptive
strategy. Because of this, the transmission
may shift firmly when first driven. This is
normal operation while the transmission
fully updates its operation to optimum
shift feel.
Battery Management System
(If
Equipped)
The battery management system monitors
battery conditions and takes actions to
extend battery life. If excessive battery
drain is detected, the system temporarily
disables some electrical systems to
protect the battery.
Systems included are:
• Heated rear window.
• Heated seats.
• Climate control.
• Heated steering wheel.
• Audio unit.
• Navigation system.
A message may appear in the information
displays to alert you that battery
protection actions are active. These
messages are only for notification that an
action is taking place, and not intended to
indicate an electrical problem or that the
battery requires replacement.
After battery replacement, or in some
cases after charging the battery with an
external charger, the battery management
system requires eight hours of vehicle sleep
time to relearn the battery state of charge.
During this time your vehicle must remain
fully locked with the ignition switched off.
271
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Maintenance

Note:
Prior to relearning the battery state
of charge, the battery management system
may temporarily disable some electrical
systems.
Electrical Accessory Installation
To make sure the battery management
system works correctly, do not connect an
electrical device ground connection
directly to the battery negative post. This
can cause inaccurate measurements of
the battery condition and potential
incorrect system operation.
Note: If you add electrical accessories or
components to the vehicle, it may adversely
affect battery performance and durability.
This may also affect the performance of
other electrical systems in the vehicle.
Remove and Reinstall the Battery
To disconnect or remove the battery, do
the following:
1. Apply the parking brake and switch the
ignition off.
2. Switch all electrical equipment off, for
example lights and radio.
3. Wait a minimum of two minutes before
disconnecting the battery.
Note: The engine management system has
a power hold function and remains powered
for a period of time after you switch the
ignition off. This is to allow diagnostic and
adaptive tables to be stored. Disconnecting
the battery without waiting can cause
damage not covered by the vehicle
Warranty.
4. Disconnect the negative battery cable terminal.
5. Disconnect the positive battery cable terminal.
6. Remove the battery securing clamp.
7. Remove the battery. 8. To install, reverse the removal
procedure.
Note: Before reconnecting the battery,
make sure the ignition remains switched off.
Note: Make sure the battery cable terminals
are fully tightened.
If you disconnect or replace the vehicle
battery, you must reset the following
features:
• Window bounce-back. See Power
Windows (page 86).
• Clock Settings.
• Pre-set radio stations.
Battery Disposal Make sure that you dispose of
old batteries in an
environmentally friendly way.
Seek advice from your local authority
about recycling old batteries.
ADJUSTING THE HEADLAMPS
Vertical Aim Adjustment
The headlamps on your vehicle are
properly aimed at the assembly plant. If
your vehicle has been in an accident, have
the alignment of your headlamps checked
by an authorized dealer.
272
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing MaintenanceE107998

Headlamp Aiming Target
8 ft (2.4 m).
A
Center height of lamp to ground.
B
25 ft (7.6 m).
C
Horizontal reference line.
D
Vertical Aim Adjustment
1. Park the vehicle directly in front of a wall or screen on a level surface,
approximately 25 ft (7.6 m) away.
2. Measure the height from the center of your headlamp indicated by a 3 mm
circle on the lens to the ground and
mark an
8 ft (2.4 m) horizontal
reference line on the vertical wall or
screen at this height, a piece of
masking tape works well.
Note: To see a clearer light pattern for
adjusting, you may want to block the light
from one headlamp while adjusting the
other.
3. Turn on the low beam headlamps to illuminate the wall or screen and open
the hood. Cover one of the headlamps
so no light hits the wall. 4. On the wall or screen you will observe
a flat zone of high intensity light at the
top of the right-hand portion of the
beam pattern. If the top edge of the
high intensity light zone is not at the
horizontal reference line, the headlamp
needs to be adjusted. 5. Locate the vertical adjuster on each
headlamp. Use a Phillips #2
screwdriver to turn the adjuster either
clockwise or counterclockwise to
adjust the vertical aim of the
headlamp.
6. Repeat Steps 3 through 7 to adjust the
other headlamp.
7. Close the hood and turn off the lamps.
273
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing MaintenanceE142592 E142465 E250054

Horizontal Aim Adjustment
The horizontal aim does not require any
adjustment for this vehicle. If a fault
occurs, have the system checked by an
authorized dealer.
WASHER FLUID CHECK
WARNING: If you operate your
vehicle in temperatures below 40°F
(5°C), use washer fluid with antifreeze
protection. Failure to use washer fluid
with antifreeze protection in cold
weather could result in impaired
windshield vision and increase the risk
of injury or accident.
Add fluid to fill the reservoir if the level is
low. Only use a washer fluid that meets
Ford specifications. See
Capacities and
Specifications (page 335).
State or local regulations on volatile
organic compounds may restrict the use
of methanol, a common windshield washer
antifreeze additive. Washer fluids
containing non-methanol antifreeze
agents should be used only if they provide
cold weather protection without damaging
the vehicle ’s paint finish, wiper blades or
washer system.
FUEL FILTER
Your vehicle is equipped with a lifetime
fuel filter that is integrated with the fuel
tank. Regular maintenance or replacement
is not needed. CHECKING THE WIPER
BLADES
Run the tip of your fingers over the edge of
the blade to check for roughness.
Clean the wiper blades with washer fluid
or water applied with a soft sponge or
cloth.
CHANGING THE WIPER
BLADES
1. Pull the wiper blade and arm away
from the glass and press the locking
buttons together. 2. Rotate and remove the wiper blade.
3. Attach the new blade to the arm and
snap it into place.
Replace wiper blades at least once per
year for optimum performance.
274
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing MaintenanceE142463 E129990

Poor wiper quality can be improved by
cleaning the wiper blades and the
windshield. See Cleaning the Windows
and Wiper Blades (page 294).
CHANGING A BULB
Replacing Reverse Lamp Bulbs
1. Make sure the lighting control is in the off position.
2. Locate the reverse lamp bulb under the
rear bumper of your vehicle. To access
the bulb, reach behind the bumper.
3. Disconnect the electrical sensor from the bulb by pulling it straight off. 4. Rotate the bulb counterclockwise and
remove it from the reverse lamp
assembly.
LED Lamps
LED lamps are not serviceable items.
Contact an authorized dealer if they fail.
The following are LED lamps:
• Headlamps.
• Rear lamp.
• Brake lamp.
• Front fog lamp.
• Front sidemarker
• Daytime running lamp. •
Central high mounted brake lamp.
• Front direction indicator.
• Rear direction indicator lamp.
• License plate lamp.
275
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing MaintenanceE177487

TRACK USE - MACH 1
Operating at High Speeds and
Track Days
Your vehicle is capable of sustained high
speeds and track day driving.
Before operating your vehicle at high
speeds:
•
Verify your tires have the correct
pressures.
• Inspect wheels and tires for wear and
damage. Replace any damaged wheels
and tires.
• Check and set lug nut torque. See
Technical Specifications (page 334).
• Verify fluid levels for oil, coolant, brake
and hydraulic fluid. See
Capacities
and Specifications (page 335).
• Change the engine oil and replace the
engine oil filter prior to use on the track.
Change the engine oil and filter again
after every four hours of track time.
Maintain the engine oil level at or near
the max mark on the engine oil dipstick.
See
Engine Oil Check (page 261).
• Replace the brake fluid with fresh
Motorcraft/Ford DOT 4 LV High
Performance Brake Fluid or other DOT
compliant fluid with a dry boiling point
greater than
500°F (260°C) from a
sealed container. Do not use silicone
or DOT 5 brake fluids. •
If you are operating your Mach 1 on a
drag strip, use drag strip selectable
drive mode in addition to using line lock
and launch control to provide a specific
set-up tuned for the quickest straight
line elapsed times.
• If you are operating your Mach 1 on a
road course, use sport or track
selectable drive modes to provide a
specific set-up tuned for optimal shift
and suspension set-up that is tuned
towards handling prowess on closed
course surfaces.
After operating your vehicle at high speeds
or track day driving, do the following:
• Set the tire pressure to the proper
specification.
• Check and set the lug nut torque. See
Technical Specifications
(page 334).
• Check all fluid levels.
• Refer to the track maintenance interval
chart. See
Normal Scheduled
Maintenance (page 444).
• Check the front and rear wheel
bearings for abnormal wear.
• Inspect brake caliper dust boots for
abnormal wear.
Track Apps WARNING:
Track Apps™
is for
track use only. Remember that even
advanced technology cannot defy the
laws of physics. It is always possible to
lose control of a vehicle due to
inappropriate driver input for the
conditions. Aggressive driving on any
road condition can cause you to lose
control of your vehicle increasing the risk
of personal injury or property damage.
276
Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Track Use