heating AUDI A4 2021 Owner´s Manual

Driver assistance

An additional indicator appears in the head-up
display*.
Changing the cruise control speed
Applies to: vehicles with cruise control system
Requirement: the system must be switched on.
> To increase or decrease the cruise control speed
in small increments, tap the lever up to the
first level toward @)/G) > page 127, fig. 105.
> To increase or decrease the cruise control speed
in larger increments, tap the lever up to the
second level toward @)/G).
> To increase or decrease the cruise control speed
continuously, tap and hold the lever at the first
or second level toward @)/G).
Overriding or deactivating the cruise
control speed
Applies to: vehicles with cruise control system
You can override or deactivate the cruise control
system. When you deactivate the system, your
cruise control speed will be stored and you can
resume that speed.
Requirement: the system must be switched on
and the regulated speed must be activated.
Overriding
> To temporarily override the cruise control
speed, press the accelerator pedal.
> To resume the stored regulated speed, remove
your foot from the accelerator pedal.
If you override the cruise control system for a
long period of time, the cruise control system
will be deactivated. The [Ud or [RM indicator
light will be displayed and the cruise control
speed will be saved.
Deactivating
> To deactivate the cruise control speed, press
the lever toward @) (not locked into place)
=> page 127, fig. 105, or
> Press the brake pedal.
128

ZA WARNING
Resting your foot on the accelerator pedal
could override the cruise control. This will pre-
vent braking interventions by the system.
See me Lai
Applies to: vehicles with cruise control system

When you switch the system off, the cruise con-
trol speed will be erased.
Requirement: the system must be switched on.
> To switch the system off, press the lever toward
@ (locked into place) > page 127, fig. 105, or
> Switch the ignition off.
Applies to: vehicles with cruise control system
Gir / 3) Speed control system: currently un-
available. See owner's manual
If the indicator light turns on and this message
appears, the cruise control system has been deac-
tivated. There is a temporary malfunction, for ex-
ample the brakes are overheating. Switch the
cruise control system on again later.
Efficiency assist
Applies to: vehicles with efficiency assist
Efficiency assist can assist the driver with predic-
tive information in order to reduce fuel consump-
tion. Depending on vehicle equipment, the sys-
tem may access data from the navigation system,
the camera behind the windshield, and the radar
sensors.
Adjusting the efficiency assist
You can adjust efficiency assist functions individ-
ually. The settings depend on the vehicle equip-
ment.
— Predictive messages > page 129.
— Predictive control > page 133.

Checking and Filling

@ Tips
The fuel filler door on your vehicle does not
lock if you lock the vehicle from the inside us-
ing
the central locking switch.
Fuel filler door emergency release
Applies to: vehicles with manual fuel filler door release

If the central locking system malfunctions, the
fuel filler door can be unlocked manually.

Fig. 155 Right side trim panel in the luggage compart-
ment: opening the trim panel

Fig. 156 Luggage compartment: fuel filler door emergency
release
The emergency opening mechanism is located
behind the right side trim panel in the luggage
compartment.
> Open the cover in the side panel > fig. 155.
> To unlock the fuel filler door, loosen the red
loop from the retainer and then pull on the
loop carefully > fig. 1569©.
> Press on the left side of the fuel filler door to
open it > page 218, fig. 153.
@) Note
Only pull on the loop until you feel resistance.
You will not hear it release. If you continue to
220

pull, you could damage the emergency re-
lease mechanism.
Emissions control
system
General information
Z\ WARNING
The temperature of the exhaust system is
high, both when driving and after stopping
the engine.

— Never touch the exhaust tail pipes once they
have
become hot. This could result in burns.
— Do not park your vehicle over flammable
materials such as grass or leaves because
the high temperature of the emissions sys-
tem could start a fire.
— Do not apply underbody protectant in the
exhaust system area, because this increases
the risk of fire.
(er) 1 id (Rel Uae lg
Observe the safety precautions > page 220, Gen-
eral information.


The vehicle may only be driven with unleaded
gasoline, or the catalytic converter will be de-
stroyed.
Never drive until the tank is completely empty.
The irregular supply of fuel that results from that
can cause engine misfires. Uncombusted fuel
could enter the exhaust system, which could
cause overheating and damage to the catalytic
converter.
Malfunction Indicator Lamp (MIL)
If the S indicator light blinks or turns on, there
is a malfunction that is causing poor emissions
quality and that could damage the catalytic con-
verter. Drive slowly to an authorized Audi dealer
or authorized Audi Service Facility to have the
malfunction corrected.

8W1012721BC
Checking and Filling

Coolant loss usually indicates that there is a leak.
Immediately drive your vehicle to an authorized
Audi dealer or authorized Audi Service Facility
and have the cooling system inspected. If the
cooling system is not leaking, coolant loss can re-
sult from the coolant boiling due overheating
and then being forced out of the cooling system.

A WARNING
— The engine compartment in any vehicle is a
potentially dangerous area. Stop the engine,
switch the ignition off, and allow the engine
to cool before working in the engine com-
partment. Always follow the information
found in > page 221, General information.
— Never open the hood if you can see or hear
steam or coolant escaping from the engine
compartment. This increases the risk of
burns. The cooling system is under pressure.
When you no longer see or hear steam or
coolant escaping, you may open the engine
compartment with caution.
— When working in the engine compartment,
remember that the radiator fan can switch
on even if the ignition is switched off, which
increases the risk of injury.
— Coolant additive and coolant can be danger-
ous to your health. For this reason, store the
coolant in the original container and away
from children. There is a risk of poisoning.

® Note
Do not continue driving if the coolant expan-
sion tank is empty. Do not add any coolant,
because air could enter the cooling system
and damage the engine. See an authorized
Audi dealer or authorized Audi Service Facility
for assistance.
Brake fluid

BFV-0229]


Fig. 162 Engine compartment: cap on brake fluid reservoir
Observe the safety precautions > page 221, Gen-
eral information.
Checking the brake fluid level
The brake fluid reservoir is located under a cover
on the driver’s side.
> Lift the cover > page 223, fig. 159 at both
openings and remove it.
> Read the brake fluid level on the brake fluid res-
ervoir > page 223, fig. 159. The brake fluid lev-
el must be between the MIN and MAX markings
of.
The brake fluid level is monitored automatically.
Messages
EG / @ Brakes: stop vehicle and check brake
fluid level
Stop the vehicle and check the brake fluid level.
See an authorized Audi dealer or authorized Audi
Service Facility for assistance.
Changing the brake fluid
Brake fluid should be changed at regular inter-
vals. Have the brake fluid changed by an author-
ized Audi dealer or authorized Audi Service Facili-
ty. The authorized Audi dealer or authorized Audi
Service Facility will inform you of the replace-
ment intervals.

Z\ WARNING
— If the brake fluid level is below the MIN
marking, it can impair the braking effect and
driving safety, which increase the risk of an

229

8W1012721BC
Checking and Filling

that the vehicle can still be started, the electrical
equipment will be limited or switched off. Some
convenience functions, such as interior lighting
or power seat adjustment, may not be available
under certain circumstances. The convenience
functions will be available again when you start
the
engine.
Even when electrical equipment is switched off,
the equipment can still drain the battery if the
vehicle is not driven for Long periods of time.
Deep draining results in a chemical reaction that
destroys the inside of the battery. The battery
must be charged every month to prevent this
= page 232. Contact an authorized Audi dealer or
authorized Audi Service Facility for more infor-
mation.
Winter operation
Cold weather places an especially high load on
the 12 Volt vehicle battery. Have the battery
checked by an authorized Audi dealer or author-
ized Audi Service Facility before cold weather be-
gins.
so that it will not be destroyed by “freezing”
=> page 232, Charging the 12 Volt vehicle
battery.
— There are electrical components under the
cargo floor behind a trim panel that warm
up during operation. To reduce the risk of
the components overheating, do not store
objects such as blankets under the cargo
floor. If the components overheat, they will
switch off temporarily. This will be indicated
by a message that will be displayed in the
instrument cluster until the temperature re-
turns to normal.
12 Volt vehicle battery
Explanation of warnings:
Always wear eye protection.

forbidden.

ZA WARNING
— All work on the battery or electrical system
in your vehicle can result in injuries, chemi-
cal burns, accidents, or burns. Because of
this, all work must be performed only by an
authorized Audi dealer or authorized Audi
Service Facility.
— Never connect a charging cable or jump
start cable directly to the 12 Volt vehicle
battery. Only use the connections in the en-
gine compartment > page 232.

ZA WARNING
California Proposition 65 Warning:
— Battery posts, terminals and related acces-
sories contain lead and lead compounds,
chemicals known to the State of California
to cause cancer and reproductive harms.
Wash hands after handling.

@) Note
— If the vehicle will be parked for long periods
of time, protect the battery against the cold
A highly explosive mixture of gases can
form when charging batteries.

Always keep children away from battery
acid and the battery.
Battery acid is highly corrosive. Always
wear protective gloves and eye protection.
® Fire, sparks, open flame, and smoking are

@/ | Always follow the instructions in the oper-
(QO | ating manual.

@) For the sake of the environment

“© % Lead-acid batteries must be disposed of
using methods that will not harm the environ-
ment. Do not dispose of them in household
trash. They contain harmful substances, such
as sulfuric acid and lead, and also recyclable
raw materials. Contact an authorized Audi
dealer or authorized Audi Service Facility for
more information.
231

8W1012721BC
Care and cleaning

— Never clean the headlights or tail lights
with a dry cloth or sponge because the
lights could be damaged.
— Do not use any cleaning products that con-
tain alcohol, because they could cause
cracks to form.
— Wheels
— Never use any paint polish or other abra-
sive materials.
— Damage to the protective layer on the
rims, such as stone chips or scratches,
must be repaired immediately.
— Camera lenses
— Never use warm or hot water to remove
snow or ice from the camera lens. This
could cause the lens to crack.
— Never use abrasive cleaning materials or
alcohol to clean the camera lens. This
could cause scratches and cracks.
— Door windows
— Remove snow and ice on windows and ex-
terior mirrors with a plastic scraper. To re-
duce the risk of scratches, move the scra-
per only in one direction and not back and
forth.
— Never remove snow or ice from door win-
dows and mirrors using warm or hot water
because this could cause cracks to form.
—To reduce the risk of damage to the rear
window defogger, do not apply any stick-
ers on the heating wires on the inside of
the window.
— Decorative parts and trim
— Never use chrome care or cleaning prod-
ucts.
— Paint
—To reduce the risk of scratches, the vehicle
must be free of dirt and dust before pol-
ishing or waxing.
—To prevent paint damage, do not polish or
wax the vehicle in direct sunlight.
—To reduce the risk of paint damage, do not
polish away rust spots.
— Remove cosmetics and sunscreen immedi-
ately because they could damage the
paint.
— Decorative decals
—To reduce the risk of damage, do not use
any rough powder or abrasive cleaning
products.
—To reduce the risk of damage, do not pol-
ish decorative decals that have a matte or
printed finish.
— Due to the risk of damage, do not use an
ice scraper to remove snow and ice on win-
dows with decorative decals on them.
— Displays and instrument cluster
— Make sure that the display and instrument
cluster are switched off and have cooled
down before cleaning. To switch off the
center display, select on the MMI home
screen: SETTINGS > Display & brightness
> MMI > Screen cleaning.
— Displays, the instrument cluster, and the
trim surrounding it must not be cleaned
with dry cleaning methods because they
could become scratched.
— Make sure no fluids enter the spaces be-
tween the instrument cluster and the
trim, because that could cause damage.
— Controls
— Make sure that no fluids enter the con-
trols, because this could cause damage.
— Safety belts
— Do not remove the safety belts to clean
them.
— Never clean safety belts or their compo-
nents with chemicals or with corrosive flu-
ids or solvents and never allow sharp ob-
jects to come into contact with the safety
belts. This could cause damage to the belt
webbing.
— If there is damage to the webbing, the
connections, the retractors, or the buck-
les, have them replaced by an authorized
Audi dealer or authorized Audi Service Fa-
cility.
— Textiles, artificial leather, and Alcantara
— Never treat artificial leather or Alcantara
with leather care products, solvents, floor
polish, shoe polish, spot remover, or simi-
lar products.
— Have a cleaning specialist remove stub-
born stains to reduce the risk of damage.
259
>

Care and cleaning

— Never use steam cleaners, brushes, hard
sponges, etc. when cleaning.
— Do not turn on the seat heating” to dry
the seat.
— Objects with sharp edges, such as zippers
or rivets on clothing or belts, can cause
damage to the surface.
— Open hook and loop fasteners, for exam-
ple on clothing, can damage seat covers.
Make sure hook and loop fasteners are
closed.
— Natural leather
— Never treat leather with solvents, floor
polish, shoe polish, spot remover or simi-
lar products.
— Objects with sharp edges, such as zippers
or rivets on clothing or belts, can cause
damage to the surface.
— Never use steam cleaners, brushes, hard
sponges, etc. when cleaning.
— Do not turn on the seat heating* to dry
the seat.
—To help prevent the leather from fading,
do not leave the vehicle in direct sunlight
for long periods of time. If leaving the ve-
hicle parked for long periods of time, you
should cover the leather to protect it from
direct sunlight.
@) Tips
— Insects are easier to remove from paint that
has been freshly waxed.
— Regular waxing can prevent rust spots from
forming.
— Decorative decals can age due to environ-
mental conditions, which can result in dam-
age such as brittleness. The color may fade
if exposed to excessive sunlight.
Taking your vehicle out
of service
If you would like to take your vehicle out of serv-
ice for a long period of time, contact an author-
ized Audi dealer or authorized Audi Service Facili-
ty. You can receive information about the meas-
ures to take depending on the conditions for tak-
260
ing the vehicle out of service (duration, location,
etc.).

Emergency assistance

@) Note
The compressor must be switched off after six
minutes at the most to reduce the risk of
overheating. Let the compressor cool down
for several minutes before using it again.
Jump starting
You should only perform the steps that follow if
you have the necessary tools and technical ex-
pertise.
If the engine does not start because the vehicle
battery is drained, you can jump start your vehi-
cle using another vehicle. Jump start cables are
needed to do this.
Both vehicle batteries must have 12 V nominal
voltage. The voltage capacity (Ah) of the vehicle
battery that is giving power must not be less
than the capacity of the drained vehicle battery.
Jump start cable
Only use a jump start cable with a large enough
diameter. Note the manufacturer's specifica-
tions.
Only use a jump start cable with insulated termi-
nal clamps.
Positive cable - usually red.
Negative cable - usually black.

ZA\ WARNING
— A drained battery can freeze at tempera-
tures around 32 °F (0 °C). If the vehicle bat-
tery is frozen, it must be thawed before con-
necting the jump start cables. If it is not,
the risk of an explosion and chemical burns
increases. After jump starting the vehicle,
drive to an authorized Audi dealer or author-
ized Audi Service Facility immediately to
have the vehicle battery checked.
— Read the warnings when working in the en-
gine compartment > page 221.
— Handling the jump start cables incorrectly
may cause the vehicle battery to explode
and lead to serious injuries.

268
@) Note
Jump start cables can cause considerable
damage to the vehicle electrical system if
they are connected incorrectly.
@) Tips
— There must be no contact between the
vehicles, or else voltage could flow when
connecting the positive terminal and drain
the vehicle battery of the vehicle providing
the jump start.
— The drained vehicle battery must be con-
nected correctly to the electrical system.
— Switch off electrical equipment that is not
needed.

Both jump start cables must be connected in the
correct order.

Fig. 179 Engine compartment: connectors for jump start
cables or a charger



Fig. 180 Engine compartment: connectors for jump start
cables or a charger
The jump start cable connections are located in
the engine compartment.
Follow the information about the vehicle battery
=> page 230. >

8W1012721BC
Fuses and bulbs

@) Note
If a new fuse burns out again shortly after you
have installed it, have the electrical system
checked as soon as possible by an authorized
Audi dealer or authorized Audi Service Facili-
t y.
G@) Tips
— The following table does not list fuse loca-
tions that are not used.
— Some of the equipment listed in the follow-
ing tables applies only to certain model ver-
sions or certain optional equipment.

Fig. 184 Driver's footwell (left-hand drive vehicle): fuse
panel with plastic clip
3
=f
= & a

x
Ss $ 2 8

Fig. 185 Front passenger's footwell (right-hand drive vehi-
cle): fuse panel with plastic clip


f ) (brown)
No. | Equipment

1 | Catalytic converter heating

2 | Engine components

Exhaust doors, fuel injectors, radiator in-
let, crankcase housing heating

Vacuum pump, hot water pump, NOx sen-
4 |sor, particulate sensor, biodiesel sensor,
exhaust doors

Brake light sensor

6 | Engine valves, camshaft adjustment

Heated oxygen sensors, mass airflow sen-
sor, water pump

Water pump, high pressure pump, high
8 |pressure regulator valve, temperature
valve, engine mount

Hot water pump, motor relay, 48 V drive-
train generator, 48 V water pump

10 | Oil pressure sensor, oil temperature sensor

Clutch position sensor, 48 V drivetrain
11 |generator, water pump, 12 V drivetrain
generator

12 | Engine valves, engine mount


13 | Engine cooling

273

Fuses and bulbs






Fuse panel @) (brown) Fuse panel (© (black)
14 | Fuel injectors, engine control module 11 Left rear door control module, left rear
15 |Ignition coils, heated oxygen sensors power window
16 | Fuel pump 12 | Parking heater
Fuse panel (®) (red) Fuse panel (0) (black)
No. | Equipment No. | Equipment

Anti-theft alarm system

Front seat electronic, seat ventilation,
rearview mirror, rear climate control sys-

































tem control panel, windshield heating, di-
agnostic connection
2 Diagnostic interface, vehicle electrical sys-
tem control module
3 |Sound generator
4 |Clutch position sensor
5S |Engine start, emergency shut-off
6 Diagnostic connection, traffic information
antenna (TMC)
7 |USB input
8 |Garage door opener
9 Audi adaptive cruise control, distance reg-
ulation
11 | Front camera
12 | Right headlight
13 | Left headlight
14 | Transmission fluid cooling
Fuse panel (©) (red)
No. | Equipment
1 {Ignition coils
2 |Climate control system compressor
S |Left headlight
6 |Automatic transmission
7 |Instrument panel
8 | Climate control system blower
9 |Right headlight
10 | Dynamic steering
11 | Engine start



2 | Engine control module
3 Left front seat electronics, lumbar sup-
port, massaging seat
4 | Automatic transmission selector lever
5 |Horn
6 |Parking brake
7 | Diagnostic interface
8 | Roof electronics control module
9 |Emergency call module
10 | Airbag control module
11 Electronic Stabilization Control (ESC), An-
ti-Lock Braking System (ABS)
12 | Diagnostic connection, light/rain sensor
13 | Climate control system
14 | Right front door control module
15 | Climate control system compressor
16 | Brake system pressure reservoir
Fuse panel (©) (black)
No. | Equipment
Front seat heating
2 |Windshield wipers
Left headlight electronics
4 Panoramic glass roof / sliding/tilting sun-
roof
5 |Left front door control module
6 | Sockets
7 Right rear door control module, right rear
power window
All wheel drive control module
9 | Right headlight electronics
10 Windshield washer system/headlight

washer system control module

274

8W1012721BC
Fuses and bulbs

Fuse assignment - Driver's side of the
(ole 4o)ig

Fig. 186 Driver side cockpit: fuse panel with plastic bracket

Fuse panel

No. Equipment

B
Convenience access and start authoriza-
tion control module





Fuse assignment - Left side of the luggage
compartment
GU -

|_8aw-0013]




2 | Audi phone box, USB input
4 |Head-up display
5 |Audi music interface, USB input
6 | Front climate control system control panel eet ofihe uagage compartment: fuse panel
7 |Steering column lock
8 |Center display Fuse panel @) (black)
9 |Instrument cluster No. | Equipment
10 | Volume control 2 |Windshield defroster
11 | Light switch, switch module 3 |Windshield defroster
12 | Steering column electronics 5 |Suspension control
14 | Infotainment system 6 |Automatic transmission
16 Steering column electronics, steering 7 |Rear window defogger
wheel heating 8 |Rear seat heating
9 |Left tail lights

10 Airbag control module

ig
Luggage compartment lid lock, fuel filler
door lock, convenience system control
module

12 Luggage compartment lid

Fuse panel @) (red)

No. Equipment

Electric compressor

Fuse panel (©) (brown)
No. Equipment


Exterior antenna

275