2021 FORD MUSTANG maintenance

If it flashes, engine misfire may be
occurring. Increased exhaust gas
temperatures could damage the catalytic
converter or other vehicle components.
Drive in a moderate fashion (avoid heavy
acceleration and deceleration) and have
your vehicle immediately serviced.
It illuminates when you switch the ignition
on prior to engine start to check the bulb
and to indicate whether your vehicle is
ready for Inspection and Maintenance
(I/M) testing.
Normally, it illuminates until the engine is
cranked and automatically turns off if no
malfunctions are present. However, if after
15 seconds it flashes eight times, this
indicates that your vehicle is not ready for
Inspection and Maintenance (I/M) testing.
See Catalytic Converter (page 161).
Shift Indicator
(If Equipped) Illuminates to inform you that
shifting to a higher gear as
indicated may give better fuel
economy and lower CO2
emissions. It will not illuminate during
periods of high acceleration, braking or
when you press the clutch pedal.
Stability Control and Traction
Control Indicator Flashes during operation.
If it does not illuminate when you
switch the ignition on, or remains
on when the engine is running, this
indicates a malfunction. Have your vehicle
checked as soon as possible.
Note: The system automatically turns off
if there is a malfunction.
See
Using Stability Control (page 176).
See Using Traction Control (page 174). Stability Control and Traction
Control Off Warning Lamp Illuminates when you switch the
system off.
Trunk Ajar Illuminates when the ignition is
on and the trunk is not
completely closed.
AUDIBLE WARNINGS AND
INDICATORS
Keyless Warning Alert
The horn sounds twice when you exit your
vehicle with the passive key and your
vehicle is in ON, indicating your vehicle is
still on. The horn also sounds twice when
you exit your vehicle and attempt to lock
the doors manually when the passive key
is still in the vehicle. The doors will not lock
if the passive key remains in the vehicle.
Headlamps On Warning Tone
Sounds when you remove the key from the
vehicle and you have left the headlamps
or parking lamps on.
Parking Brake On Warning Tone
Sounds when you have left the parking
brake on and drive your vehicle. If the
warning tone remains on after you release
the parking brake, have the system
checked by your authorized dealer
immediately.
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Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Instrument Cluster E138639 E130458 E159323

Action
Message
You have successfully programmed a passive key to the system.
Key Program
Successful
You have failed to program a passive key to the system.
Key Program
Failure
You have programmed the maximum number of keys to the system.
Max Number of
Keys Learned
You have not programmed enough keys to the system.
Not Enough Keys
Learned
The key battery is low. Change the battery as soon as possible.
Key Battery Low
Replace Soon
Inform the driver that they are exiting the vehicle and the engine is on.
Engine ON
Maintenance Action
Message
Stop your vehicle as soon as safely possible and turn off the engine.
Check the oil level. If the warning stays on or continues to come onwith your engine running, have the system checked as soon as possible.
Low Engine Oil
Pressure
The engine oil life remaining is 10% or less.
Change Engine Oil
Soon
The oil life left is at 0%.
Oil Change
Required
The brake fluid level is low, inspected the brake system immediately.See Brake Fluid Check (page 269).
Brake Fluid Level
Low
The brake system needs servicing. Stop your vehicle in a safe place. Have the system checked.
Check Brake
System
Indicates that your vehicle is still in Transport mode. This may not
allow some features to operate properly. Have the system checked.
Transport Mode
Contact Dealer
Indicates that your vehicle is still in Factory mode. This may not
allow some features to operate properly. Have the system checked.
Factory Mode
Contact Dealer
The powertrain needs service due to a powertrain malfunction.
See Manual
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Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Information Displays

WHAT IS THE CABIN AIR
FILTER
The cabin air filter improves the quality of
air in your vehicle by trapping dust, pollen
and other particles.
LOCATING THE CABIN AIR
FILTER
The cabin air filter is behind the glovebox.
Note:
The filter access door is above the
passenger footwell under the instrument
panel.
REPLACING THE CABIN AIR
FILTER
Replace the filter at regular intervals. See
Scheduled Maintenance (page 441).
Note: Make sure you have a cabin air filter
installed at all times. This prevents foreign
objects from entering the system. Running
the system without a filter in place could
result in degradation or damage to the
system.
Note: Using an aftermarket cabin air filter
could reduce cabin air filtration and climate
control performance.
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Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Interior Air Quality

EMISSION LAW
WARNING: Do not remove or alter
the original equipment floor covering or
insulation between it and the metal floor
of the vehicle. The floor covering and
insulation protect occupants of the
vehicle from the engine and exhaust
system heat and noise. On vehicles with
no original equipment floor covering
insulation, do not carry passengers in a
manner that permits prolonged skin
contact with the metal floor. Failure to
follow these instructions may result in
fire or personal injury.
U.S. federal laws and certain state laws
prohibit removing or rendering inoperative
emission control system components.
Similar federal or provincial laws may
apply in Canada. We do not approve of any
vehicle modification without first
determining applicable laws. Tampering with emissions
control systems including
related sensors can result in
reduced engine power and the illumination
of the service engine soon light.
Tampering With a Noise Control
System
Federal laws prohibit the following acts:
• Removal or rendering inoperative by
any person other than for purposes of
maintenance.
• Repair or replacement of any device or
element of the design incorporated into
a new vehicle for the purpose of noise
control prior to its sale or delivery to
the ultimate purchaser or while it is in
use.
• The use of the vehicle after any person
removes or renders inoperative any
device or element of the design. The U.S. Environmental Protection Agency
may presume to constitute tampering as
follows:
•
Removal of hood blanket, fender apron
absorbers, fender apron barriers,
underbody noise shields or acoustically
absorptive material.
• Tampering or rendering inoperative the
engine speed governor, to allow engine
speed to exceed manufacturer
specifications.
If the engine does not start, runs rough,
experiences a decrease in engine
performance, experiences excess fuel
consumption or produces excessive
exhaust smoke, check for the following:
• A plugged or disconnected air inlet
system hose.
• A plugged engine air filter element.
• A clogged fuel filter.
• Contaminated fuel.
• Air in the fuel system, due to loose
connections.
• Fuel system leaks, due to loose
connections.
• An open or pinched sensor hose.
• Incorrect engine oil level.
• Incorrect fuel for climatic conditions.
• Incorrect engine oil viscosity for
climactic conditions.
Note: Some vehicles have a lifetime fuel
filter that is integrated with the fuel tank.
Regular maintenance or replacement is not
needed.
Note: If these checks do not help you
correct the concern, see your authorized
dealer as soon as possible.
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Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Engine Emission Control

CATALYTIC CONVERTER
WARNING: Do not park, idle or
drive your vehicle on dry grass or other
dry ground cover. The emission system
heats up the engine compartment and
exhaust system, creating the risk of fire. WARNING:
The normal operating
temperature of the exhaust system is
very high. Never work around or attempt
to repair any part of the exhaust system
until it has cooled. Use special care when
working around the catalytic converter.
The catalytic converter heats up to a very
high temperature after only a short
period of engine operation and stays hot
after the engine is switched off. WARNING:
Exhaust leaks may
result in entry of harmful and potentially
lethal fumes into the passenger
compartment. If you smell exhaust
fumes inside your vehicle, have your
vehicle inspected immediately. Do not
drive if you smell exhaust fumes.
Your vehicle has various emission control
components and a catalytic converter that
enables it to comply with applicable
exhaust emission standards.
To make sure that the catalytic converter
and other emission control components
continue to work properly:
• Do not crank the engine for more than
10 seconds at a time.
• Do not run the engine with a spark plug
lead disconnected.
• Do not push-start or tow-start your
vehicle. Use booster cables. See Jump
Starting the Vehicle
(page 234).
• Use only the specified fuel listed.
• Do not switch the ignition off when your
vehicle is moving. •
Avoid running out of fuel.
• Have the items listed in scheduled
maintenance information performed
according to the specified schedule.
Note: Resulting component damage may
not be covered by the vehicle Warranty.
The scheduled maintenance items listed
in scheduled maintenance information are
essential to the life and performance of
your vehicle and to its emissions system.
If you use anything other than Ford,
Motorcraft or Ford-authorized parts for
maintenance replacements or for service
of components affecting emission control,
such non-Ford parts should be equivalent
to genuine Ford Motor Company parts in
performance and durability.
Illumination of the service engine soon
indicator, charging system warning light or
the temperature warning light, fluid leaks,
strange odors, smoke or loss of engine
power could indicate that the emission
control system is not working properly.
An improperly operating or damaged
exhaust system may allow exhaust to
enter the vehicle. Have a damaged or
improperly operating exhaust system
inspected and repaired immediately.
Do not make any unauthorized changes to
your vehicle or engine. By law, vehicle
owners and anyone who manufactures,
repairs, services, sells, leases, trades
vehicles, or supervises a fleet of vehicles
are not permitted to intentionally remove
an emission control device or prevent it
from working. Information about your
vehicle ’s emission system is on the Vehicle
Emission Control Information Decal
located on or near the engine. This decal
also lists engine displacement.
Please consult your warranty information
for complete details.
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Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Engine Emission Control

On-Board Diagnostics (OBD-II)
Your vehicle has a computer known as the
on-board diagnostics system (OBD-II) that
monitors the engine
’s emission control
system. The system protects the
environment by making sure that your
vehicle continues to meet government
emission standards. The OBD-II system
also assists a service technician in properly
servicing your vehicle. When the service engine soon
indicator illuminates, the OBD-II
system has detected a
malfunction. Temporary malfunctions may
cause the service engine soon indicator to
illuminate. Examples are:
1. Your vehicle has run out of fuel —the
engine may misfire or run poorly.
2. Poor fuel quality or water in the fuel —the engine may misfire or run
poorly.
3. The fuel fill inlet may not have closed properly. See Refueling (page 156).
4. Driving through deep water —the
electrical system may be wet.
You can correct these temporary
malfunctions by filling the fuel tank with
good quality fuel, properly closing the fuel
fill inlet or letting the electrical system dry
out. After three driving cycles without these
or any other temporary malfunctions
present, the service engine soon indicator
should stay off the next time you start the
engine. A driving cycle consists of a cold
engine startup followed by mixed city and
highway driving. No additional vehicle
service is required. If the service engine soon indicator remains
on, have your vehicle serviced at the first
available opportunity. Although some
malfunctions detected by the OBD-II may
not have symptoms that are apparent,
continued driving with the service engine
soon indicator on can result in increased
emissions, lower fuel economy, reduced
engine and transmission smoothness and
lead to more costly repairs.
Readiness for Inspection and
Maintenance (I/M) Testing
Some state and provincial and local
governments may have
Inspection/Maintenance (I/M) programs
to inspect the emission control equipment
on your vehicle. Failure to pass this
inspection could prevent you from getting
a vehicle registration.
If the service engine soon
indicator is on or the bulb does
not work, your vehicle may need
service. See On-Board Diagnostics.
Your vehicle may not pass the I/M test if
the service engine soon indicator is on or
not working properly (bulb is burned out),
or if the OBD-II system has determined
that some of the emission control systems
have not been properly checked. In this
case, the vehicle is not ready for I/M
testing.
If the vehicle ’s engine or transmission has
just been serviced, or the battery has
recently run down or been replaced, the
OBD-II system may indicate that the
vehicle is not ready for I/M testing. To
determine if the vehicle is ready for I/M
testing, turn the ignition key to the on
position for 15 seconds without cranking
the engine. If the service engine soon
indicator blinks eight times, it means that
the vehicle is not ready for I/M testing; if
the service engine soon indicator stays on
solid, it means that your vehicle is ready
for I/M testing.
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Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Engine Emission Control

Cross Traffic Alert Indicator
When the system detects an
approaching vehicle, a tone
sounds, a warning lamp
illuminates in the relevant exterior mirror
and arrows appear in the information
display to show which side the
approaching vehicle is coming from.
Note: If arrows do not display, a message
appears in the information display. If the system malfunctions, a warning lamp
illuminates in the instrument cluster and
a message appears in the information
display. Have your vehicle checked as soon
as possible.
Note:
In exceptional conditions, the system
could alert you, even when there is nothing
in the detection zone, for example a vehicle
passing further away from your vehicle.
Cross Traffic Alert Information Messages Action
Message
Displays instead of indication arrows when the system
detects a vehicle. Check for approaching traffic.
Cross Traffic Alert
Indicates blocked cross traffic alert system sensors. Clean
the sensors. If the message continues to appear, have your
vehicle checked as soon as possible.
Cross Traffic Not Avail-
able Sensor Blocked See
Manual
The system has malfunctioned. Have your vehicle checked
as soon as possible.
Cross Traffic System
Fault
Displays if you attach a trailer to your vehicle.
Cross Traffic Alert Deac-
tivated Trailer Attached
STEERING
Electric Power Steering WARNING: The electric power
steering system has diagnostic checks
that continuously monitor the system. If
a fault is detected, a message displays
in the information display. Stop your
vehicle as soon as it is safe to do so.
Switch the ignition off. After at least 10 seconds, switch the ignition on and
watch the information display for a
steering system warning message. If a
steering system warning message
returns, have the system checked as
soon as possible.
WARNING: If the system detects
an error, you may not feel a difference in
the steering, however a serious condition
may exist. Have your vehicle checked as
soon as possible. Failure to do so may
result in loss of steering control.
Your vehicle has an electric power steering
system, there is no fluid reservoir, no
maintenance is required.
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Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Driving AidsE268294

ESSENTIAL TOWING CHECKS
Follow these guidelines for safe towing:
•
Do not tow a trailer until you drive your
vehicle at least 1,000 mi (1,600 km).
• Consult your local motor vehicle laws
for towing a trailer.
• See the instructions included with
towing accessories for the proper
installation and adjustment
specifications.
• Service your vehicle more frequently if
you tow a trailer. See your scheduled
maintenance information.
• If you use a rental trailer, follow the
instructions the rental agency gives
you.
You can find information on load
specification terms found on the tire label
and Safety Compliance label as well as
instructions on calculating your vehicle's
load in the Load Carrying chapter. See
Load Limit
(page 213).
Remember to account for the trailer
tongue weight as part of your vehicle load
when calculating the total vehicle weight.
Hitches
Do not use a hitch that either clamps onto
the bumper or attaches to the axle.
Distribute the trailer load so 10-15% of the
total trailer weight is on the tongue.
Safety Chains
Note: Never attach safety chains to the
bumper.
Always connect the safety chains to the
hook retainers of your vehicle hitch.
To connect the safety chains, cross them
under the trailer tongue and allow enough
slack for turning tight corners. Do not allow
the chains to drag on the ground. Trailer Brakes WARNING:
Do not connect a
trailer's hydraulic brake system directly
to your vehicle's brake system. Your
vehicle may not have enough braking
power and your chances of having a
collision greatly increase.
Electric brakes and manual, automatic or
surge-type trailer brakes are safe if you
install them properly and adjust them to
the manufacturer's specifications. The
trailer brakes must meet local and federal
regulations.
The rating for the tow vehicle's braking
system operation is at the gross vehicle
weight rating, not the gross combined
weight rating.
Trailer Lamps WARNING:
Never connect any
trailer lamp wiring to the vehicle's tail
lamp wiring; this may damage the
electrical system resulting in fire. Contact
your authorized dealer as soon as
possible for assistance in proper trailer
tow wiring installation. Additional
electrical equipment may be required.
Trailer lamps are required on most towed
vehicles. Make sure all running lights, brake
lights, direction indicators and hazard lights
are working.
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.
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Mustang (CZG) Canada/United States of America, Vehicles Built From: 14-09-2020, enUSA, Edition date: 202010, Second-Printing Towing