2021 AUDI A4 Battery

8W1012721BC
Checking and Filling

The hood latch is not locked correctly. Stop im-
mediately and close the hood.
K WARNING
— Never open the hood when there is steam or
coolant escaping from the engine compart-
ment, because there is a risk that you could
be burned. Wait until no steam or coolant is
escaping.
— For safety reasons, the hood must always be
latched securely while driving. Because of



NY [1
this, always check the hood after closing it
to make sure it is latched correctly. The hood
is latched if the front corners cannot be lift-
ed.
— If you notice that the hood is not latched
while you are driving, stop immediately and
close it, because driving when the hood is
not latched increases the risk of an accident.



Fig. 159 Typical location of the reservoir and the engine oil filler opening (example)
Observe the safety precautions > page 221.
@ Washer fluid reservoir (>) > page 233
) Jump start points: (+) under the cover
= page 232, Charging the 12 Volt vehicle
battery > page 268, Preparation

Engine oil filler opening (%27) > page 225

Sticker* for engine oil specifications
=> page 224


) Coolant expansion tank (-£) > page 228
Brake fluid reservoir (OC) > page 229
The coolant expansion tank and the engine oil
filling opening may be located in different places
within
the engine compartment, depending on
the engine version.
223

Checking and Filling


accident. Do not continue driving. See an au-
thorized Audi dealer or authorized Audi
Service Facility for assistance.
— If the brake fluid is old, bubbles may form in
the brake system during heavy braking. This
could impair braking performance and driv-
ing safety, which increases the risk of an ac-
cident.
— The brake fluid in your vehicle must meet
the standard VW 501 14 and is available at
an authorized Audi dealer or authorized
Audi Service Facility. If this brake fluid is not
available, another high-grade brake fluid of
equivalent quality may be used, and it must
meet the U.S. Federal Motor Vehicle Stand-
ard (FMVSS) 116 DOT 4, Class 6.

Switch off all electrical equipment that is not
needed. If necessary, some equipment will be
switched off automatically. Vehicle functions or
driving stability may be limited. Drive to an au-
thorized Audi dealer or authorized Audi Service
Facility immediately.
z= Electrical system: low battery charge. Bat-
tery
will be charged while driving
The starting ability may be impaired.
If this message turns off after a little while, the
vehicle battery has charged enough while driving.
If this message does not turn off, drive immedi-
ately to an authorized Audi dealer or authorized
Audi Service Facility.

@) Note
— If the brake fluid level is above the MAX
marking, brake fluid may leak out over the
edge of the reservoir and result in damage
to the vehicle.
— Do not allow any brake fluid to come into
contact with the vehicle paint, because it
will corrode the paint.
Electrical system
If the = / B or = indicator light turns on,
there is a malfunction in the power supply, the
battery, or the vehicle electrical system.
mz / B Electrical system: malfunction! Safely
stop vehicle
Do not continue driving and switch the ignition
off > A\. See an authorized Audi dealer or author-
ized Audi Service Facility for assistance.
= Electrical system: malfunction! Restart not
possible. Please contact Service
If you switch the ignition off, you will not be able
to restart the vehicle. Vehicle functions or driving
stability may be limited. Drive to an authorized
Audi dealer or authorized Audi Service Facility im-
mediately.
= Electrical system: malfunction! Please con-
tact Service
230
ZA\ WARNING
When there is an electrical system malfunc-
tion, vehicle functions may not work and driv-
ing stability may be limited, which increases
the risk of an accident. Do not continue driv-
ing and switch the ignition off. See an author-
ized Audi dealer or authorized Audi Service Fa-
cility for assistance.

Battery
ela lame (Tem eeecela)
Because of the complex power supply, all work on
batteries such as disconnecting, replacing, etc.,
should only be performed by an authorized Audi
dealer or authorized Audi Service Facility > A\.
Multiple batteries with different technologies
may be installed in your vehicle:
— Vehicle battery (for example, for starting the
engine, basic power supply) > page 231, 12
Volt vehicle battery or > page 232, Other bat-
tery types
— Auxiliary battery (for example, for recuperation
or optional equipment) > page 232, Other bat-
tery types
Not running the vehicle for long periods of
time
The battery will gradually drain if the vehicle
does not run for long periods of time. To ensure >

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

Checking and Filling

Other battery types
Explanation of warnings:


Fire, sparks, open flame, and smoking are
& forbidden.
Always keep children away from battery
@) acid and the battery.


@/ | Always follow the instructions in the oper-
fQ) | ating manual.

ZA\ WARNING
All work on the batteries must only be per-
formed by an authorized Audi dealer or au-
thorized Audi Service Facility.
— Gases that escape from these different bat-
tery types can be poisonous or flammable.
— The contents of these battery types can be
corrosive. If any battery contents come into
contact with the skin, flush the affected
area for at least 15 minutes with clean wa-
ter. Then wash the affected area with soap.
Have the affected area examined by a medi-
cal professional.
@) Note
Components must not be connected to the
battery terminals and wires on these battery
types because this increases the risk of dam-
age, for example due to overvoltage.

@ For the sake of the environment
“These types of batteries must be dis-
posed of using methods that will not harm
the environment. Do not dispose of them in
household trash. They contain harmful sub-
stances and recyclable raw materials. Contact
an authorized Audi dealer or authorized Audi
Service Facility for more information.
232
rging the 12 Volt vehicle battery

Fig. 163 Engine compartment: connectors for a charger or
jump start cables
Observe the safety precautions > page 221, Gen-
eral information, > /\ in Battery general infor-
mation on page 231 and > /\.
Requirement: only use chargers with a maximum
charging current of 14.8 volts. The battery ca-
bles remain connected.
The charging cable connections are located in the
motor compartment. The ground point ©) is al-
ways located on the vehicle body.
> Switch off the ignition and all electrical equip-
ment.
> Open the hood > page 222.
> Press the release lever on the positive terminal
and fold the cover upward > fig. 163.
> Clamp the charger terminal clamps to the jump
start pins according to the instructions. (Hex
head bolt under a cover @), ground point on the
vehicle body ©)).
> Insert the power cable for the charging device
into the socket and switch the device on.
>» At the end of the charging process, switch the
charger off and pull the power cable out of the
socket.
> Remove the charging device terminal clamps.
> Close the cover on the positive terminal.
> Close the hood > page 222.

ZA WARNING
— 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. >

8W1012721BC
Checking and Filling


— A highly explosive mixture of gases can form
when charging batteries. Only charge the
battery in well-ventilated areas.
— A drained battery can freeze at tempera-
tures around 32 °F (0 °C). Do not charge or
use a frozen or thawed battery. If ice forms,
the battery housing can crack and battery
electrolyte can leak out, which increases the
risk of an explosion and chemical burns.
Contact an authorized Audi dealer or author-
ized Audi Service Facility for more informa-
tion.
— Do not connect or disconnect the charging
cable while charging because this increases


the risk of an explosion.

@) Tips
Read all of the manufacturer's instructions
for the charger before charging the battery.
Windshield washer
system

B8W-0125



Fig. 164 Engine compartment: washer fluid reservoir cap
Observe the safety precautions > page 221, Gen-
eral information.
The windshield washer reservoir © contains the
cleaning solution for the windshield/rear win-
dow* and the headlight washer system*
> fig. 164, > page 223. The reservoir capacity
can be found in > page 287.
To reduce the risk of lime scale deposits on the
spray nozzles, use clean water with low amounts
of calcium. Always add window cleaner to the wa-
ter. When the outside temperatures are cold, an
anti-freezing agent should be added to the water
so that it does not freeze.
Messages
3 Please add washer fluid
Fill the washer fluid for the windshield washer
system and the headlight washer system* when
the ignition is switched off.
@) Note
— The concentration of anti-freezing agent
must be adjusted to the vehicle operating
conditions and the climate. A concentration
that is too high can lead to vehicle damage.
— Never add radiator anti-freeze or other addi-
tives to the washer fluid.
— Do not use a glass cleaner that contains
paint solvents, because this could damage
the paint.
Service interval display
The service interval display detects when your ve-
hicle is due for service.
The service interval display works in two stages:
— Inspection or oil change reminder: after driv-
ing acertain distance, a message appears in the
instrument cluster display each time the igni-
tion is switched on or off. The remaining dis-
tance or time is displayed briefly.
— Inspection or oil change due: if your vehicle
has reached an inspection or oil change interval
or both intervals at the same time, the mes-
sage Inspection due! or Oil change due! or Oil
change and inspection due! appears briefly af-
ter switching the ignition on or off.
Checking service intervals
You can check the remaining distance or time un-
til the next oil change or next inspection in the
Infotainment system.
Applies to MMI: Select on the home screen: VE-
HICLE > Settings & Service > Service intervals.
Resetting the indicator
An authorized Audi dealer or authorized Audi
Service Facility will reset the service interval dis-
play after performing service.
233
>

Wheels

Production options weight
means the combined weight of
those installed regular production
options weighing over 5 lbs.
(2.3 kg) in excess of those stand-
ard items which they replace, not
previously considered in curb
weight or accessory weight, in-
cluding heavy duty brakes, ride
levelers, roof rack, heavy duty
battery, and special trim.
Radial ply tire
means a pneumatic tire in which
the ply cords that extend to the
beads are laid at substantially
90 degrees to the centerline of
the tread.
Recommended inflation
pressure
see > page 238, Cold tire infla-
tion pressure.
Reinforced tire
means a tire designed to operate
at higher loads and at higher in-
flation pressures than the corre-
sponding standard tire. Rein-
forced tires may be identified as
“XL”, “xl”, “EXTRA LOAD”, or “RF”
on the sidewall.
240
Rim
means a metal support for a tire
or a tire and tube assembly upon
which the tire beads are seated.
Rim diameter
means nominal diameter of the
bead seat. If you change your
wheel size, you will have to pur-
chase new tires to match the new
rim diameter.
Rim size designation
means rim diameter and width.
Rim width
means nominal distance between
rim flanges.
Sidewall
means that portion of a tire be-
tween the tread and bead.
Speed rating (letter code)
means the speed at which a tire is
designed to be driven for extend-
ed periods of time. The ratings
range from 93 mph (150 km/h)
to 186 mph (298 km/h) > table
on page 236. You may not find
this information on all tires be-
cause it is not required by law.
The speed rating letter code,
where applicable, is molded on
the tire sidewall and indicates the >

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
Emergency assistance

Connecting the positive cable (red) to the
positive terminal
> Open the cover on the positive terminal
> fig. 179.
1. Attach one end of the positive cable (red) to
the jump-start pin @ © fig. 180 on your vehi-
cle.
2. Attach the other end of the positive cable
(red) to the positive terminal @ on the pow-
er source.
Connecting the negative cable (black) to the
negative terminal
3. Attach one end of the negative cable (black)
to the negative terminal @) on the power
source.
4. Attach the other end of the negative cable
(black) to the jump-start pin @) on the vehi-
cle.
Starting the engine
>» Start the engine in the vehicle giving the charge
and let it run at idle.
> Now start the engine in your vehicle, which has
the
drained battery.
> If the engine does not start, stop the starting
procedure after 10 seconds and then repeat it
after approximately 30 seconds.
> Turn on the rear window defogger in your vehi-
cle in order to reduce any voltage peaks that
may occur when disconnecting the jump start
cables. The headlights must be switched off.
> With the engines running, remove the cables in
reverse order of the way they were installed.
> Close the cover on the positive terminal.

ZA WARNING
— Never connect the jump start cable directly
to your vehicle battery. Only use the connec-
tions in the engine compartment.
— Do not touch the non-insulated parts of the
terminal clamps. The cable must also not
come into contact with vehicle components
that conduct electricity when it is connected
to the positive vehicle battery terminal. This
can cause a short circuit.
— The plugs on the battery cells must not be
opened.

— Keep ignition sources (such as open flames,
burning cigarettes, etc.) away from the vehi-
cle batteries to reduce the risk of an explo-
sion.
— Route the jump start cables so they cannot
get caught in the moving parts in the other


vehicle's engine compartment.
() Note
Please note that the connecting process previ-
ously described for the jump start cables is in-
tended for when your vehicle is being jump
started.
G) Tips
Make sure that the connected jump start ca-
bles have sufficient contact with metal.

Towing
General information
You should only perform the steps that follow if
you have the necessary tools and technical ex-
pertise.
Towing requires a certain amount of practice.
Audi recommends contacting a towing company
to have the vehicle transported.
You should only have your vehicle towed by an-
other vehicle when disabled in exceptional cir-
cumstances. Inexperienced drivers should not
tow.
Notes on towing
When the engine is stopped, the transmission
will not be sufficiently lubricated if traveling at
high speeds and long distances:
— The maximum permitted towing speed is 30
mph (50 km/h).
— The maximum permitted towing distance is 30
miles (50 km).
Additional information on towing with a tow
truck
The vehicle may only be towed with the front axle
raised. Do not wrap any chains or cables around
the brake lines.
269
>