brake AUDI A8 2021 Repair Manual

4N0012721BF
Emergency assistance

Emergency assistance
General information
> Park the vehicle as far as possible from moving
traffic in the event of a breakdown. In the event
of a flat tire, park the vehicle ona level surface.
If you are ona steep hill, be especially careful.
> Set the parking brake.
> Switch the emergency flashers on.
> Have the passengers exit the vehicle. They
should move to a safe place, for example be-
hind a guard rail.

zs

, WARNING
Follow the steps given above. This is for your
protection and the for the safety of others on
the road.

Equipment
Vehicle tool
vehicle jack
Applies to: vehicles with the vehicle tool kit, tire mobility kit,
and vehicle jack




Applies to: vehicles with conventional drive system
Fig. 191 Luggage compartment: cargo floor cover





Applies to: vehicles with plug-in hybrid drive
Fig. 192 Luggage compartment: cover

Conventional drive system: The vehicle tool kit,
vehicle jack*, tire mobility kit*, and compressor*
are stored in the luggage compartment under
the cargo floor cover > fig. 191.
Plug-in hybrid drive: The vehicle tool kit, tire mo-
bility kit, and compressor are located on the rear
side
of the cover and in the compartment under-
neath > fig. 192.
Conventional drive system
> Lift the cargo floor by the plastic handle
> fig. 191.
> Hook the handle into the luggage compart-
ment weather strip.
> Applies to: vehicles with spare tire: Turn the
handle counter-clockwise and remove the spare
tire.
> Unhook the cargo floor cover before closing the
luggage compartment lid.
Plug-in hybrid drive
> Open the cover using the handle > fig. 192.
Conventional drive system: Depending on the
equipment, the vehicle tool kit and the tire mobi-
lity kit* may be located under the spare tire*, un-
der another cover, or in the tool box.
Tips
— The vehicle jack* does not require any main-
tenance.
— Plug-in hybrid drive: The vehicle must not
be operated without a tire mobility kit.
Tire mobility kit
Applies to: vehicles with tire mobility kit
> Read and follow the important safety precau-
tions > page 317.
> Set the parking brake.
> Select the “P” position.
> Check if a repair with the tire mobility kit is pos-
sible > page 318.
317

Emergency assistance

> Set the parking brake.
> Select the “P” position.
>» When towing a trailer: disconnect the trailer
from your vehicle.
> Lay out the vehicle tool kit > page 317 and the
spare tire > page 323.
» Applies to MMI: Select on the home screen: VE-
HICLE > Settings & Service > Air suspension:
wheel change.
> Switch the ignition off.

ZA\ WARNING
The vehicle must also be secured to prevent it
from rolling when using the vehicle jack”. Use
suitable objects to block the front and back of
the wheel that is diagonal from the wheel
with the flat tire.

Removing the caps


nb oD i)
ail z a

Ve

ae)


é
Fig. 196 Wheel: wheel bolts with caps
> Slide the plastic clip from the vehicle tool kit
onto the cap until it engages > fig. 196.
> Remove the cap with the plastic clip.
320

Tada more) bed
Applies to: vehicles with anti-theft wheel bolts



B4H-0470

Fig. 197 Anti-theft wheel bolt with cap and adapter
You need a special adapter in the vehicle tool kit
to remove the anti-theft wheel bolts.
> Remove the cap @).
> Slide the adapter @) all the way onto the anti-
theft wheel bolt @.
> Slide the wheel wrench* from the vehicle tool
kit all the way onto the adapter @).
> Loosen the wheel bolt > page 320.
@ Tips
Note the code number for the wheel bolt
adapter and store it in a safe place separate
from the vehicle. If you need a replacement
adapter, contact an authorized Audi dealer or
authorized Audi Service Facility and give them
the code number.
Loosening the wheel bolts

B4S-0221

Fig. 198 Wheel: loosening the wheel bolts

Emergency assistance

@® Note
Do not lift the vehicle by the sill. Position the
vehicle jack only at the designated mounting
points on the side sill. Otherwise, your vehicle
could be damaged.
Removing and installing a wheel
@ &
= x
oO oO

B8K-1477


Fig. 202 Wheel: alignment pin in the top hole
Removing a wheel
> Remove the top wheel bolt completely using
the hex socket in the screwdriver handle from
the vehicle tool kit > fig. 201 and place it ona
clean surface.
> Then install the alignment pin from the vehicle
tool kit by hand in the empty wheel bolt hole
> fig. 202”.
> Remove the rest of the wheel bolts.
> Remove the wheel >(). The alignment pin re-
mains in the hole while doing this.

D Applies to: vehicles with ceramic brake rotors*: Use a sec-
ond alignment pin* from the vehicle tool kit for the lowest
hole according to the steps described for the first align-
ment pin.
322
Installing a wheel
Read the directions on S page 322 when instal-
ling unidirectional tires.
> Slide the wheel on over the alignment pin >@.
> Install the wheel bolts and tighten them gently
using the hex socket.
> Remove the alignment pin and tighten the re-
maining wheel bolt.
> Carefully lower the vehicle using the vehicle
jack*.
> Tighten the wheel bolts in a diagonal pattern
using the wheel wrench*.
The wheel bolts must be clean and loosen and
tighten easily. Check the contact surfaces for the
wheel and hub. Contaminants on these surfaces
must be removed before installing the wheel.

ZA\ WARNING
— Read and follow the important information
and notes under > page 296.
— Never use the hex socket in the screwdriver
handle to tighten the wheel bolts. Using the
hex
socket will not achieve the required
tightening torque, which increases the risk
of an accident.
@) Note
When removing or installing the wheel, the
rim could hit the brake rotor and damage the
rotor. Work carefully and have a second per-
son help you.
Ue lieraeCelar | mae}
A unidirectional tire profile is identified by arrows
on the tire sidewall that point in the running di-
rection. You must always maintain the specified
running direction. This is necessary to ensure the
tire's optimal performance in regard to adhesion,
running noise, and friction, and to reduce the risk
of hydroplaning.

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

Emergency assistance

bar is not available. Use a towing cable made of
synthetic elastic cable similar elastic material.

ZA WARNING
— Towing highly increases the risk of an acci-
dent, for example from colliding with the
towing vehicle.
— To reduce the risk of an accident, do not al-
low anyone to remain inside the vehicle
when it is being transported by a tow truck
or a special transporter.
@) Note
— If normal towing is not possible, for exam-
ple if the transmission is faulty or if the
towing distance is greater than 30 miles
(50 km), then transport the vehicle on a
special carrier.
— If the vehicle is towed by a tow truck at the
axle that is not permitted, this can cause se-
vere damage to the transmission.
— The vehicle must not be tow started for
technical reasons.
@) Tips
— If the power supply is interrupted, then it
will not be possible to move the selector
lever out of the "P" position. The parking
lock must be released using the emergency
release before towing the vehicle
=> page 112.
— Switch Audi pre sense* off > page 181 when
loading the vehicle onto a vehicle carrier,
train, ship, or other type of transportation,
or when towing the vehicle. This can prevent
an undesired intervention from the pre
sense* system.
— Follow the local legal regulations for tow-
ing.
Read and follow the important information under
=> page 325.


326
Preparations
> Only secure the towing cable or tow bar at the
designated towing loops > page 327,
=> page 327.
> Make sure the towing cable is not twisted. Oth-
erwise it could disconnect from the towing loop
while towing.
> Switch the emergency flashers on in both
vehicles > page 61. However, do not do this if it
prohibited by law.
Towing vehicle (front)
> Only start to drive when the towing cable is
taut.
> Press the brake pedal very carefully.
> Avoid sudden braking or driving maneuvers.
Vehicle being towed (rear)
> Make sure the ignition is switched on so that
the steering wheel is not locked and so that you
can use the turn signals, the horn, and the
windshield wipers if needed > A\.
> Switching it off before the vehicle has stopped
may impair the function of the brake booster
and power steering. You would then need to
use more force to steer and brake the vehicle.
> Release the parking brake > page 121.
> Select the “N” selector lever position.
> Make sure the towing cable is always taut.

ZA\ WARNING
— Never tow a vehicle using a tow bar or tow-
ing cable if the vehicle does not have electri-
cal power.
— If the vehicle runs out of power while it is
being towed, stop towing the vehicle imme-
diately and consult an authorized Audi deal-
er or qualified repair facility.

4N0012721BF
Fuses and bulbs


This can cause damage to the electrical sys-
tem and increases the risk of fire.

Fuse panel (2) (brown)


() 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-
ty.
@ 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.
Fuse assignment - left footwell
Fig. 209 Left footwell: fuse panel with plastic clip

Fuse panel @ (brown)
No. | Equipment

Engine ignition coils

Engine start, electric drive clutch

Windshield wiper control module

Left headlight electronics


Ul
WIN)
eR
Climate control system blower

6 | Instrument panel

Windshield wipers

Zz
8 |High-voltage heating, compressor
9 Panoramic glass roof

Fuse panel (2) (black)
No. | Equipment

1 |Engine mount

N Left rear door control module

Windshield washer system/headlight
washer system




4 |Right headlight electronics
5 | Front seat heating
6 |Right rear door control module
7 |Sockets
8 | Left front door control module
9 |Parking heater
Fuse panel @) (red)

No. | Equipment

Anti-theft alarm system

Engine control module

Horn

Parking brake

Diagnostic interface

Roof electronics control module

WOlLOINI
DI
WIN]
rR
Driver assistance systems control module

10 | Airbag control module

Electronic Stabilization Control (ESC), An-
LL
ti-Lock Braking System (ABS)

Rear climate control unit, diagnostic con-
12
nector, light/rain sensor


Climate control system, vehicle electrical
13
system control module

14 | Right front door control module

Climate control system compressor, vehi-
15
cle electrical system control module

16 | Brake system pressure reservoir

Fuse panel (@) (black)

No. | Equipment


1 |Engine components

329

Fuses and bulbs








Fuse assignment - left side of cockpit
RAZ-0202

Fig. 210 Left side of the cockpit: fuse panel with plastic
clip






Fig. 211 Left side of the luggage compartment: fuse panel
with plastic clip
2 | Engine components 10 | Volume control
3 | Engine components 11 | Light switch, switch panels
4 |Engine components 12 | Steering column electronics
5 | Brake light sensor 14 | MMI Infotainment system control module
6 | Engine components 15 |Steering column adjustment
7 |Engine components 16 | Steering wheel heating
8 | Engine components
9 | Engine components ae ft side of the luggage
10 | Oil pressure sensor, oil temperature sensor (eelar|PEINE Ee
11 | Engine components g
12 | Engine components
13 | Engine cooling
14 | Engine control module, fuel injectors
15 | Engine sensors
16 | Fuel pump









330
No. Equipment No. | Equipment
Climate control system, interior air sensor 1_| Thermal management
2 | Audi phone box 5 |Air suspension/suspension control
Climate control system, fragrance system, 6 |Automatic transmission control module
3 particulate matter sensor 7 |Right rear seat adjustment
4 |Head-up display 8 | Rear seat heating
S_ |Audi music interface, USB input 9 |
Left tail light
6 |Instrument panel 10 | Front belt tensioner on driver's side
7 | Steering column lock
8 |Upper/lower display
9 |Instrument cluster

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

4N0012721BF
Data privacy

Data privacy
Privacy
notice
You can find information about responsibility for
data protection in the MMI.
Transmitted information
Applies to: MMI: Select on the home screen: SET-
TINGS > General > Legal notes > About Audi
connect.
Image recording
Surrounding area monitoring
Applies to: vehicles with surrounding area monitoring
The functionality of the park assist plus requires
detecting and evaluating the vehicle's path. This
is done by cameras installed permanently on the
vehicle that detect objects in the vehicle's sur-
roundings (such as obstacles or guard rails). The
live images from the cameras are transmitted to
the applicable control module.
The camera images are transferred to the respon-
sible control module for processing and may be
stored, depending on vehicle equipment. The
control
module analyzes the current camera im-
age using image evaluation software. This image
evaluation software detects anonymized techni-
cal measurements, such as distances to objects.
The control module evaluates these technical
measurements and makes it possible for the as-
sist systems to control the vehicle, if necessary.
Data memories
5 io. oO
2 x= + oO


Fig. 212 Driver's side footwell: connection port for the On
Board Diagnostic System (OBD)
Your vehicle is equipped with electronic control
modules for various vehicle systems such as the
airbags. These vehicle control modules store data
while driving normally that is required by an au-
thorized Audi dealer or authorized Audi Service
Facility for diagnosis and repair purposes. Only
certain types of data are recorded for a very short
period of time if a control module has detected a
system event. No noises, conversations, or im-
ages will be recorded in the vehicle.
The data may include information such as the ve-
hicle speed, the direction of travel, and informa-
tion about the brake system, or also the behavior
of the restraint system in the event of an acci-
dent. The stored data can be exported and down-
loaded with special devices, which must be con-
nected directly to the vehicle.
On Board Diagnostic System (OBD)
There is a diagnostic connector socket in the driv-
er's side footwell to read out the various control
modules and the event data recorder. Data re-
garding the function and condition of the elec-
tronic control modules is stored in the event
memory. Only have an authorized Audi dealer or
authorized Audi Service Facility read out and de-
lete the event memory.

ZA\ WARNING
— Incorrect use of the connection port for the
On Board Diagnostic System can cause mal-
functions, which can then result in accidents
and serious injuries.
— Only allow an authorized Audi dealer or au-
thorized Audi Service Facility to read out the
engine data.
h data recorder
Event Data Recorder

This vehicle is equipped with an Event Data Re-
corder (EDR). The main purpose of an EDR is to
record, in certain crash or near crash-like situa-
tions,
such as an airbag deployment or hitting a
road obstacle, data that will assist in understand-
ing how a vehicle's system performed. The EDR is
designed to record data related to vehicle dynam-
ics and safety systems for a short period of time, >
333

Data privacy

typically 30 seconds or less. The EDR in this vehi-
cle is designed to record such data as:
— How various systems in your vehicle were oper-
ating;
— Whether or not the driver and passenger safety
belts were buckled/fastened;
— How far (if at all) the driver was depressing the
accelerator and/or brake pedal; and,
— How fast the vehicle was traveling.
These data can help provide a better understand-
ing of the circumstances in which crashes and in-
juries occur. NOTE: EDR data are recorded by your
vehicle only if a non-trivial crash situation occurs;
no data are recorded by the EDR under normal
driving conditions and no personal data (e.g.
name, gender, age, and crash location) are re-
corded. However, other parties, such as law en-
forcement, could combine the EDR data with the
type of personally identifying data routinely ac-
quired during a crash investigation.
To read data recorded by an EDR, special equip-
ment is required, and access to the vehicle or the
EDR is needed. In addition to the vehicle manu-
facturer, other parties, such as law enforcement,
that have the special equipment, can read the in-
formation if they have access to the vehicle or the
EDR.
Assist system monitor
This vehicle is equipped with an Assist System
Monitor (ASM). The ASM collects data that is not
stored by the EDR in the event of an accident. The
main task of the ASM is to make it possible to un-
derstand the role and the behavior of the assist
systems in these accident situations. In addition
to the data that the EDR stores, the ASM records
data related to the assist systems starting sever-
al seconds before the accident or near-accident.
The data collected by ASM depends on the equip-
ment and may include the following information:
status information of the assist systems (for ex-
ample, if they are switched on or off, system
events, etc.), control interventions (for example,

D_ System availability may be limited depending on the mar-
ket.
2) In preparation at the time of printing.
334
by ESC, ABS, Audi pre sense’, etc.), and assist
systems settings (such as speed settings).
Special devices and access to the vehicle or to the
ASM are necessary in order to read the data from
the ASM memory. In addition to the vehicle man-
ufacturer, third parties such as law enforcement
authorities can also read and analyze the stored
data if they have access to the vehicle or to the
ASM.
Data usage
Audi can read out the information stored in the
data memories or similar data, or give this infor-
mation to third parties, especially in the follow-
ing situations:
— If the vehicle owner or lessee agrees
— If there is an official request from the police
— Ifa court or authorities request it
If legally permitted, Audi can also use the data
for analysis of vehicle operation and safety per-
formance or provide this data to third parties for
research purposes.
Data memory for autonomous driving!)
Applies to: vehicles with data memory for autonomous driv-
ing
When park assist plus is active > page 198, data
is stored in a memory in the vehicle. This data is
continuously overwritten by more current data
after a few seconds. The data is erased when the
ignition is switched off.
In certain situations, such as if an airbag has
been triggered or a parking process was ended,
the corresponding technical data may be stored
in the data memory for autonomous driving. The
data memory for autonomous driving is a read-
only memory that has a limited amount of stor-
age space. If the storage space is full, the oldest
data will be overwritten with the newest data. >