2021 AUDI A8 battery

4N0012721BF
Checking and Filling

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 285, 12
Volt vehicle battery or > page 286, Other bat-
tery types
— Auxiliary battery (for example, for recuperation
or optional equipment) > page 286, Other bat-
tery types
— Plug-in hybrid drive: High-voltage battery (for
example, for electric driving) > page 131, In-
troduction.
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
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 286. 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.

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 286.

Z\ 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
so that it will not be destroyed by “freezing”
=> page 286, 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.

Battery acid is highly corrosive. Always
wear protective gloves and eye protection.

Fire, sparks, open flame, and smoking are
forbidden.

Z\ WARNING
— All work on the battery or electrical system
in your vehicle can result in injuries, chemi-
cal burns, accidents, or burns. Because of

A highly explosive mixture of gases can
form when charging batteries. >
@
>
©

285

Checking and Filling


Always keep children away from battery
acid and the battery. @
@/
oo

Always follow the instructions in the oper-
ating manual.

@ For the sake of the environment
2 ¥ 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.
Other battery types
Explanation of warnings:
® ®
@/
oo

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-
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.

286
@) For the sake of the environment

OE 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.
arging the 12 Volt vehicle battery

Fig. 185 Engine compartment: connectors for a charger or
jump start cables
Observe the safety precautions > page 274, Gen-
eral information, > /\ in Battery general infor-
mation on page 285 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 276.
» Press the release lever on the positive terminal
and fold the cover upward > fig. 185.
> 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. >

4N0012721BF
Checking and Filling

> Close the cover on the positive terminal.
> Close the hood > page 276.

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 286.
— 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

B4M-0135)

Fig. 186 Engine compartment: washer fluid reservoir cap
Observe the safety precautions > page 274, Gen-
eral information.
The windshield washer reservoir <> contains the
cleaning solution for the windshield and the
headlight washer system* > fig. 186,
= page 277. The reservoir capacity can be found
in > page 344.
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
|} Please add washer fluid
Fill the washer fluid for the windshield washer
system and the headlight washer system* when
the ignition is switched off.
CG) 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 a certain 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.
287

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 292, 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.
294
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 290. 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 >

4N0012721BF
Emergency assistance

To benefit fully from the advantages of the uni-
directional tire design, you should replace faulty
tires as soon as possible and restore the correct
running direction on all of the tires.
> Reinstall the caps on the wheel bolts if necessa-
ry.
> Store the vehicle tool kit in its designated
place.
> If the removed wheel does not fit in the spare
wheel well, store it securely in the luggage
compartment > page 97.
> Check the tire pressure on the installed wheel
as soon as possible.
> Correct the tire pressure and store it in the MMI
=> page 308.
> The wheel bolt tightening specification must be
90 ft lbs (120 Nm). Have it checked as soon as
possible with a torque wrench. Drive carefully
until then.
> Have the faulty wheel replaced as quickly as
possible.
Space-saving spare tire
Applies to: vehicles with space-saving spare tire (compact
spare tire)
The spare tire is intended for short-term use only.
Have the damaged tire checked and replaced if
necessary by an authorized Audi dealer or author-
ized Audi Service Facility as soon as possible.
There are some restrictions on the use of the
compact spare tire. The compact spare tire has
been designed specifically for your type of vehi-
cle. Do not replace it with the spare tire from an-
other type of vehicle.
The compact spare tire is located in the luggage
compartment under the cargo floor cover
=> page 317.
The tire pressure must be adjusted to a specified
value listed on the tire pressure sticker
=> page 299, fig. 190.
Snow chains
For technical reasons, the use of snow chains on
the compact spare tire is not permitted.
If you have to drive with snow chains and a front
tire fails, mount the spare tire in place of a rear
tire. Install the snow chains on the rear tire that
you removed, and install that in place of the
front tire that failed.

ZA WARNING
— After installing a spare tire, the tire pressure
must be checked as soon as possible.
— Do not drive faster than 50 mph (80 km/h)
with a compact spare tire. Driving faster
than that increases the risk of an accident.
— To reduce the risk of an accident, avoid hard
acceleration or braking and driving fast
around curves with the compact spare tire.
— To reduce the risk of an accident, never drive
with more than one compact spare tire.
— Normal summer or winter tires must not be
mounted on the compact spare wheel rim.

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.
323

Emergency assistance


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 274.
— Handling the jump start cables incorrectly
may cause the vehicle battery to explode
and lead to serious injuries.

@) Note
— Jump start cables can cause considerable
damage to the vehicle electrical system if
they are connected incorrectly.
— Plug-in hybrid drive: You must not give a
jump start with your vehicle. This could
cause significant damage to the electrical
system in your vehicle.
G) 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.
324

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

Fig. 203 Engine compartment: connectors for jump start
cables or a charger



Fig. 204 Connecting the jump start cables
T
he jump start cable connections are located in
the engine compartment.
Fi ollow the information about the vehicle battery
=> page 284.
Connecting the positive cable (red) to the
positive terminal
>
I.
Open the red cover on the positive terminal
> fig. 203.
Attach one end of the positive cable (red) to
the jump-start pin @ ° fig. 204 on your vehi-
cle.
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
n
3
egative terminal
. Attach one end of the negative cable (black)
to the negative terminal @) on the power
source. >

4N0012721BF
Emergency assistance

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 red cover on the positive terminal.

Z\ 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.
@) 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.
Tow bar and towing cable
The vehicle can be towed with a tow bar or tow-
ing cable. Both drivers should be familiar with
the special considerations when towing, especial-
ly when using a towing cable.
Always make sure the traction force does not ex-
ceed the permitted level and there are no shock
loading conditions. There is always the risk of the
coupling becoming overloaded when driving off-
road.
For the most safety and security, drive with a tow
bar. You should use a towing cable onlyifatow >
325

4N0012721BF
Fuses and bulbs





















































Fuse panel () (black) Fuse panel @) (brown)
Luggage compartment lid central locking, 15 |Left rear seat adjustment
11 | fuel filler door, sunshade, luggage com- Front belt tensioner on front passenger's
partment cover 16 side
12 | Luggage compartment lid control module
— Fuse panel (4) (black)
Fuse panel (2) (red) No. | Equipment
No. | Equipment Seat ventilation, rear seat heating, rear-
1 | Rear climate control system blower 1 |view mirror, refrigerator, diagnostic con-
2 | Exterior antenna nection
3 | Exhaust treatment, sound actuator 2 | Gateway control module (communication)
4 |Rear climate control system control panel 3 [Sound actuator
5 | Right trailer hitch light 4 |Transmission heating valve
6 |Trailer hitch positioning motor 5 |Engine start, electric drive
7 |Trailer hitch release 7 |Active accelerator pedal
8 | Left trailer hitch light 8 | Night vision assist, active suspension
9 |Trailer hitch socket 9 _|Adaptive cruise assist
10 |Allroad sport differential 1 Intersection assistant, driver assist sys-
11 | Exhaust treatment tems, radar systems, camera systems
12 |48 V drivetrain generator 2 || Exteriorsoundigenerator
13 | USB input
Fuse panel (3) (brown) 14 [Right headlight
No. | Equipment 15 |Left headlight
1 |Driver assistance systems control module :
2 |Rear Audi phone box Fuse panel () (red)
3 | Rear seat adjustment No:.| Equipment
4 |Side assist 1 | Active suspension
5 |Sereensinthe rear 2 |Service disconnect switch
6 |Tire pressure monitoring system 3_|Refrigerator
7 [Emergency call system 4 | Electric drive system
Auxiliary heating radio receiver, tank mod- 5 |/Brake-system
8 ule 6 | High-voltage battery water pump
9 | Automatic transmission selector lever 7 |Auxiliary climate control
0 TV tuner, data exchange and telematics 8 |Climate control system compressor
control module 9 |Auxiliary battery control module
rT Convenience access and start authoriza- 10 | High-voltage battery
tion control module 11 | High-voltage charger
12 | Garage door opener 14 | Thermal management
13 | Rearview camera, peripheral cameras 15 | Thermomanagement control module
Convenience system control module, right -
14 | Vil light Fuse panel 6) (white)
No. | Equipment
1 |Rear center armrest heating

331