2021 AUDI A4 battery replacement

Opening and closing


ZA\ WARNING
If batteries or coin cell batteries are swal-
lowed or enter the body in any other way, they
can cause serious or fatal injuries within a
short period of time. There is a risk of chemi-
cal burns.
— Keep vehicle keys and key fobs with batter-
ies out of the reach of children.
— Keep new or used batteries away from chil-
dren.
— If the battery compartment on a vehicle key
does not close securely, stop using the key
and keep it away from children.
— Seek medical attention immediately if you
suspect that a battery was swallowed or has
entered the body in any other way.


@ For the sake of the environment
Discharged batteries must be disposed of us-
ing
methods that will not harm the environ-
ment. Do not dispose of them in household
trash.
G) Tips
Replacement batteries for the vehicle key
must meet the same specifications as the
original battery.
Luggage compartment
lid
(ee eles)
Z\ WARNING
— Applies to vehicles with anti-theft alarm sys-
tem: When the vehicle is locked from the
outside, no one - especially children - should
remain in the vehicle, because the windows
can no longer open from the inside
= page 36. Locked doors make it more diffi-
cult for emergency workers to enter the ve-
hicle, which puts lives at risk.
— Always close and lock the luggage compart-
ment lid and the doors when the vehicle is
not in use. Otherwise someone such as a
child could enter the vehicle through the
luggage compartment and become locked


inside it. To reduce the risk of injury, do not
allow children to play in or around the vehi-
cles
—To reduce the risk of injuries by pinching,
make sure that no one is in the operating
area of the luggage compartment lid, in-
cluding the hinge areas and the upper and
lower edge of the luggage compartment lid.
—
After closing the luggage compartment lid,
make sure that it is latched. The luggage
compartment lid could open suddenly while
driving, which would increase the risk of an
accident.
— Never drive with the luggage compartment
lid ajar or open, because poisonous gases
from the surrounding area can enter the ve-
hicle interior and increase the risk of asphyx-
iation.
— If there is a luggage rack (such as a bicycle
rack) on the luggage compartment lid, the
luggage compartment lid may not open
completely under certain circumstances or it
could close by itself if open due to the extra
weight. Therefore, the open luggage com-
partment lid must be given additional sup-
port or the cargo must first be removed
from the luggage rack.
— Applies to vehicles with power-operated or
sensor-controlled luggage compartment lid:
Pay careful attention when closing the lug-
gage compartment lid. Otherwise, you could
cause serious injury to yourself or others de-
spite the pinch protection.



40
@) Note
The luggage compartment lid can bump into
objects such as the garage ceiling when open-
ing and become damaged.
@ Tips
— When the vehicle is locked, the luggage
compartment lid can be unlocked separately
by pressing the “S button twice on the vehi-
cle key. The luggage compartment lid locks
automatically when it is closed again.
— The ability to open the luggage compart-
ment lid using the handle can be deactivat-
ed or activated in the MMI > page 34. >

Fuses and bulbs


2 | Audi phone box

Right front seat electronics, lumbar sup-
port, massaging seat
4 |Side assist


6 |Tire pressure monitoring system

Convenience access and start authoriza-
tion control module

8 | Auxiliary heating, tank module

TV tuner, data exchange and telematics
10 control module

11 | Auxiliary battery control module

12 | Garage door opener

13 | Rearview camera, peripheral cameras
14 | Right tail lights
16 | Airbag control module



No. | Equipment

Exhaust treatment
Right trailer hitch light
Trailer hitch
Left trailer hitch light
Trailer hitch socket


WO)
O};N]/
Mm|
Ww

All wheel drive control module, sport dif-
10
ferential


11 | Exhaust treatment

Bulbs
Replacing bulbs
Audi recommends having a bulb replaced by an
authorized Audi dealer or authorized Audi Service
Facility in cases of doubt. These facilities have
the correct tools and replacement parts as well
as the required technical knowledge.
LED lights*
Your vehicle is equipped with maintenance-free
headlights and tail lights. However, if a light bulb
needs to be replaced, please contact an author-
ized Audi dealer or authorized Audi Service Facili-
ty.
276

If you still would like to try replacing the
bulbs in your vehicle yourself, read the warn-
ings regarding working in the engine compart-
ment > A\ in General information on
page 221.

Make sure the covers are fitted correctly on
the headlight and tail light so that no water
will leak in from the outside and the light
function will not be impaired.

8W1012721BC

HFP
refer to Hands Free Profile............. 162
High beams
High beam assistant.................4. 52
Highway lights ....... 0... cece eee eee ee ee 51
Hill descent assist..............02-000. 108
Hill descent control............0 eee eee 107
Hill hold assist... 0.0.2... ee ee eee eee 97
Home
refer to Home address...........-000% 187
Home address ....... 0.00.0. c eee eee ee 187
HomeLink
refer to Garage door opener............. 48
Home screen... ... 2. eee e eee eee eee eee 18
HOM... eee eee 6
Hotspot
refer to Wi-Fi...........0. 2.0 e eee eee 176
I
Idle
fefer to Gears ewes ¢ s ewes ce seen cs wees 8: 97
Ignition
Switching onvand Off". wes x y says « ¢ caver « 9 95
Imbalance (wheels) ............000000 0s 244
Immobilizer
refer to Electronic immobilizer........... 37
Indicatorlights » neow ¢ a wes ¢ ewer ws wares ao ee 7
INSpPectionintetWals ¢ ssw < gapen g x paves se ne 233
INStroMment ClUStErs = wasn s x wom » x eowe sy ew 12
Adjusting the layout................00. 13:
Cleaning........ 0... eee eee eee eee 258
ENGin@: code: « = sas ¢ seas ¢ eee ae Heese 215
Failures: «osc 2s mene oe pews se ee ¥ ee 12
On-board computer............00200 eee 16
Operating...............2.. 0.02.0 000 13
Service interval display................ 233
Software information................. 215
Switching tabs..................200005 13
Switching the view............ 00ers 13
Vehicle functions................00000- 16
Version information...............0-5 215
Instruments
Adjusting illumination.................. 55
Integrated Toll Module................. 125
Intelligent search
Navigation’: « s sxe 5 ¢ caw + + seein s o tees = 182
Interior lighting « . esccms ve ewe ve mes vw 54,55
Interior MONitOriNg’s + 2 wesw ce wows s ween a ae 36
Intermittent mode (windshield wipers) ..... 58
International’ travel... seessieivaseveuea Li?
Internet
veferto:connects =» ssw ss wees eo wes 2 oe 173
Internet radio
refer to Online radio.............. 197,198
iPhone
refer to Audi music interface........... 202
J
Jump starting......................00. 268
K
ROY". ccanees i a: sonra i ot samme +o anames o 9 ames @ 33,37
Convenience opening and closing......... 46
Key replacement.........c:eecceeeeees 37
Mechanical key...........0...000 02000 37
PANIC button ....... 2.20... 00 cece eee eee 38
Replacing the battery.................. 39
Unlocking and locking.............e eee 38
Vehicle code... 6.2.2... eee eee eee eee 37
Key user... 2... ee eee ee eee 31
RICK EOWING. « ccenerts «a: eames 0 a ayngen eo acne 9 me 99
L
Lane assist
refer to Audi active lane assist.......... 141
Lane departure warning
refer to Audi active lane assist.......... 141
Laptimer........... 0.000000. 0.0 2000. 124
Evaluating s « saws « & cae & & eee so ees os 125
StANEIINGsis 6 & conse w o owen 7 cummins & 7 aE & > 124
LATCH (securing child safety seats)......... 78
Leather care and cleaning............... 258
Legal information
License subscriptions................. 215
Software information................. 215
Software licenseSicx « s wews ss wee s genes 215
Version information...............000- 21S
License plate: brackets + scies 6 seen 3 6 ser 283
Lifting points (vehicle jack).............. 264
293

Index

Parking lock
Manually releasing.............00000- 100
also refer to Gears... 6... eee e eee eee 97
Partition W@t sca < ssces v enees s aren ase 86, 87
Pass-through... .... cc eee cence eens 86
Pedals... 2... cece eee eee eee 99
Perchlorate ....... 0. eee eee ee eee 281
Peripheral cameras............0.000085 152
Phone
Connecting a second mobile device...... 163
Disconnecting a mobile device.......... 164
SONGS ccsain » iam © © wravens a % aosmem w v soveTs 6 169
Phonebook
refer to Directory.......... 0. e ee eae 167
PIN
A-digit myAudi PIN.................00. 30
PROLECHON sev: « ¢ cee x o cares § e oem oe ee 31
Playback (media). . sss. ss sees ie cease ee 203
Podcast
refer to Online radio.............. 197,198
POLISHINGisax « ¢ eee + & eee Eee a Ree a ee 257
Pollen filter
refer to Pollutant filter................. 90
Pollutant filter’: . aces ss seee s bees ween as 90
POWEP SOUPCES:: « = seme: =v seme ee meee e 82, 202
Power WiINdOWS ......... 0 eee e eee eens 45
Malfunction ns san 2 wean es ween a 2 wees = 45
Power windows malfunction.............. 45
Predictive control.............-.00e000- 133
Predictive messages..............--005- 129
pre sense
refer to Audi presense................ 143
Presentation mode..............-+-008 192
Presets
RadiGicres s ¢ eves 5 2 neues x 5 Haus oe ROWS FB: 196
Presets list
Feferto Presetsicis <2 sais Pressure
Tire pressure monitoring system........ 253
Tif@S': + : asvox ¢ & eaime & & eG 3 5 HORS 7 ES 245
Profile picture... . eee eee eee ee eee 30
Protecting ..... 0... 0c cece cece eee 257
Pyrotechnic elements..............000 281
296
Q
quattro... 2... eee 112
Selective wheel torque control.......... 113
R
RSGiG}: = : suse » 5 mews ¢ 2 Swe 2 a eee x eee 193
RadiOteXtiscn casi a i ance @ a anemia oo anew 196
Station list... 2.0.0... ee eee 193
Radio communications equipment........ 283
Radio‘equipment ....... eeen ee een ee eee 283
Radio Standards Specification (RSS) ....... 284
Rain/light sensor
Automatic headlights.................. 51
Intermittent mode (windshield wipers).... 58
Random
refer to Shuffle: . s sses s+ ovens peewee: 205
Range (fuel level) .................00000. 16
Reading lights.............. 2.000 eee eee 54
Rear cross-traffic assist.............0005 156
Rear lid
refer to Luggage compartment lid........ 41
Rear seatS.. 1... . cee eee eee 85, 86
Rear shelf
refer to Storage area behind the rear head
FEStrAINES wssve 2 o wawere oo esi ¥ 6 Rae @ 8 eens 83
Rearview camera... 12.1... ee eee eee eenes 152
Rear window defogger...............000 93
Rear wiper blades
Changing sec = wee ws were ov nee oo ae 8 60
Cleaning..... 2... . 6. cece eee 60
Recirculation mode..............--00005 92
RECUPERATION cesses vu suceae « & cameson ww eames ow Re 16
Refrigerant Oilivics = 5 wean eo wenn eo wwe 2 a0 287
Refueling’: ss sees 2 = saws 7 5 tees Fe ewe ro: 218
Remote access authorization (key user)..... 31
Remote control
Garage door opener..............2+-00. 48
Remote control key.............---.e eee 37
Convenience opening and closing......... 46
Key replacement...............--000-- 37
LED = suse 3 = wens = » owime oy ceeme se Rees ee 39
PANICTUMECIONS: « cscsses cs wrencce so ansnesa 3 8 arene 37
Replacing the battery.................. 39
Unlocking and locking...............005 38
also refer to Vehicle key..............-. 37