2021 AUDI A4 check oil

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


— 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
>

Checking and Filling

If you have changed the oil yourself, you must re-
set the oil change interval.
Applies to: MMI: To reset the display, select on
the home screen: VEHICLE > Settings & Service
> Service intervals.
@) Note
— Only reset the oil change indicator if the oil
was changed.
— Following the service intervals is critical to
maintaining the service life and value of
your vehicle, especially the engine. Even if
the mileage on the vehicle is low, do not ex-
ceed the time for the next service.
234

8W1012721BC
Wheels

Wheels Wheels
and Tires
General information
> Check your tires regularly for
damage, such as punctures,
cuts, cracks, and bulges. Remove
foreign objects from the tire
tread.
>If driving over curbs or similar
obstacles, drive slowly and ap-
proach the curb at an angle.
> Have faulty tires or rims re-
placed immediately.
>Protect your tires from oil,
grease, and fuel.
>Mark tires before removing
them so that the same running
direction can be maintained if
they are reinstalled.
>Lay tires flat when storing and
store them ina cool, dry location
with as little exposure to light as
possible.

A WARNING
—Never drive faster than the
maximum permitted speed for
your tires. This could cause the
tires to heat up too much. This
increases the risk of an acci-
dent because it can cause the
tire to burst.


—Always adapt your driving to
the road and traffic condi-
tions. Drive carefully and re-
duce your speed on icy or slip-
pery roads. Even winter tires
can lose traction on black ice.

() Note
—Please note that summer and
winter tires are designed for
the conditions that are typical
in those seasons. Audi recom-
mends winter tires during the
winter months. Low tempera-
tures significantly decrease
the elasticity of summer tires,
which affects traction and
braking ability. If summer
tires are used in very cold tem-
peratures, cracks can form on
the tread bars, resulting in
permanent tire damage that
can cause loud driving noise
and unbalanced tires.
—Burnished, polished or
chromed rims must not be
used in winter driving condi-
tions. The surface of the rims
does not have sufficient corro-
sion protection for this and
could be permanently dam-
aged by road salt or similar
substances.
235

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

8W1012721BC
Index


Battery
Charging (12 Volt vehicle battery)....... 232
Vehicle battery (12 Volt)............... 230
Winter operation (12 Volt vehicle battery) . 231
BLOCK POU cei: «x were: oo ceamewe oo semen 2 o seems 187
BLOWN: sess: ¢ = seene « x wanes g 2 meee 5 2 ee 4 ee 92
Bluetooth
Audio playen snus « 2 sassws ae suesens ov srw 9 2 3 201
Connecting adevice..............0000- 214
Connecting a mobile phone............ 162
Deleting a device
Device overvieW............00-.0 eee
Disconnecting a device................ 214
Displaying profiles..................0. 215
Selecting adevice.............0..000. 214
Specifying a favorite.................. 215
Boost... 6... eee eee eee 15
Boost pressure indicator................. 15
Brake fluid
Checking the brake fluid level........... 229
BrakeS.. 0... eee eee 104
Brak@fluid(: = = sams = « eam = woven se pee as 229
Emergency braking function............ 106
0) 107
New brake pads............. 00s e eee 104
Braids « savay » © aaiwa & Raeoe ¢ & SanDR ES Se ES 216
Break-in security feature............00005 36
Breaking in
New brake pads..............----000- 104
NeWetiresis « wcuin as maces a meme a 2 emma ee 242
Browser
refer to Media center...............00. 204
Businessiaddressis i s, svessns sc scan a a veamiws a aa 187
c
California Proposition 65 Warning........ 222
Battery specific...............00-0 00 231
GALLUISE sacsse + ogsiese 0 9 axons 0 4 exexeus 4 2 anneew a 166
Cameras
Coverage areaS............-.0. 000000. 118
LOGAUIONS a: « ¢ apes ¢ nates 3 paee 5 x PEER GE 119
Capacities
Puelitankss sss so somes a sess @ o aves ¥ 0 ond 287
Washer fluid reservoir................. 287
Garwashh x 5 sews « onsmeus © scagens os ayers «6 @ some 255
Gatalytic converter « sis 2 weve eo wee ee cree 220
Cell phone
refer to Telephone............00 eee eee 162
Cell phone compartment
refer to Audi phone box............... 164
Central locking...... cece eee cree eee 33
AULOILOGK « coos 2 5 seme 5 5 ete so wows Go eG 33
Convenience key sie © « socsais 2 6 srvoem + 6 voese 38
Convenience opening and closing......... 46
Luggage compartment lid............... 4l
Mechanically unlocking and locking....... 36
MessageS ......--. 0c cece eects 35
Remote control key........:0ee eee ee eee 38
SEUNG’: © wave: s 2 wecems ve arene @ aetna ¥ ewee 34
Vehicle key... 0... cece eee ee eee ee 38
Central locking switch..............0000. 35
Ceramic Drakesinis © «cassie © x seve ¥ @ suena # ane 104
Certification): « . cee: ss wean ov enw os eee « 284
Charging
refer to Power sourceS..........-.000005 82
Charging the battery
Mobile devices..................00005 202
USB': « meme 2 ¢ anus © naueu & x REINS & ¥ ORE & 165
Witelessis «secs x x woos 2 v cervaue a x stone 2 9 oon 165
Child safety lock
Climate control system controls in the rear. 44
POWEr WINDOWS! si: = © xsnas 4 § Seen & & Maram 4 es 44
Rear dOOrsis + o omc sc sami oo me oases 44
Child safety seats..............---.00005 76
Securing to the top tether anchor........ 80
Securing with a safety belt.............. 79
Securing: with LATCH s « sw « & nome « ¢ sans « 78
ClEATIAG saves 5 x nore 5 2 wows ot eee xe eee 255
Cleaning Alcantara.............-.00000. 258
Cleaning artificial leather............... 258
Cleaning carbon components........ 257, 258
Cleaning controls..................005. 258
Cleaning decorative parts andtrim........ 257
Cleaning exhaust tail pipes.............. 257
Cleaning plastic parts...........00 eee 257
Cleaning textiles = cass ¢ & exes ¢ cae se ees 258
Climate control system ............00000- 90
also refer to Automatic climate control sys-
GNA. 2 execs © 2 ceeueve = ueueat © + steams © meme = © 90
Climate control system controls in the rear
Child safety lock........... 0. cece eee 44
289

8W1012721BC

Drive select

refer to Audi drive select.............0. 110
Drive system... 1.2... cee ee eee 101
AUdi drive Select sais s & news < ¢ says & 3 ve 110
Drive system (message) ........... eee eee 103
Driving down hills............ 00.000 eee 107
DFIVIMGJPFOGFAMM:. « wnaceos % 0 spesine 6 & axonese on mune 137
Driving through water...............0.. 108
Driving CIM: « cescues & a ssanees vw ones vv orn a 8 a 16
Driving tips
Driving through water...............-- 108
Efficient driving...............-00000- 102
Offroad GriWitG cows sc caws se pean es ewan 108
Uphill and downhill................00. 107
Driving:up Wills: « ssc s 2 wave 6 o sree wv sew 107
Dust filter
refer to Pollutant filter................. 90
DYMAMMIGIStEORIAG, cxsieos ov secre © « soneers © ¥ soaser Lill
E
EFimailss os i: cwcsan oa ncewios ow sesnin @ ononans wa wretnon 4 T/1,
Settings............. 0.00. e eee eee ee 171
EDL
refer to Electronic Differential Lock...... 113
EDR
refer to Event Data Recorder (EDR)...... 277
Efficiency ASSISE: s wes » x ows & a ews 8 6 ow 128
Predictive :comtro lin: « cxvim x 0 sensawe oo swowane 133
Electrical system ........ 2... cee eee eee 230
Electromechanical parking brake......... 106
Electronic Differential Lock.............. 113
Electronic immobilizer................5-. 38
Electronic Stabilization Control........... 113
Embedded SIM card............--.00005 174
Emergency assistance...............00. 261
Emergency braking function............. 106
Emergency call... «ccc. 2 mwa ve ewe 169,178
Emergency flashers..............--0000- 53
Emergency modéw Emergency operation
DOONS eves ov comme a a same ao omnes vv om x
Fuel filler door
Luggage compartment lid............... 43
Panoramic glass roof................005 47
Sliding/tilting sunroof...............00. 46
Emissions control system..............- 220
EnergyCOnsSUMErSi. & & sive a 2 wasn ao mare oes 16
Energy management...............0005 102
Engine
Breakingiin « sss c= cee = 2 aves ov ere a ee 101
Coolant..... 0.0... cece eee eee ee eee 227
EMe@ngenty StOpis « = ewes 5 2 sees ¢ 2 wees Fs me 95
JUMp'StARtING & vesi% « 6 war % 6 senens & ewes 268
Start/Stop system ......... 0. eee ee eee 102
Starting/Stopping:: « « seme os ews 5 wen s « 95
Engine compartment
Opening and closing the hood.......... 222
OVERVIEW cscssiic xo ciueins xo anette 6H atetaaie © ooetts 223
Safety precautions..................0. 221
Engine oil
AGQING = ex ¢ = seem « = ress « ¢ ee § pe 224
GhANGING sis «sess ss rena « waver 2» omen © 226
Checking oil level.............00-.000- 224
CONSUMPtIONs « 2 was s 2 ene x eee 5 oe 224
Indicator light « sss + «owes sw ssweenn ow vase 224
Replacement interval................. 233
Temperature display............0.e00e 15
Engine sound
Audi driveselect’s osx. < + sx » x come © ee 110
Engine Start/Stop mode
refer to Start/Stop system............. 102
Engine startsystem sce 3 5 seu o 9 was o 9 som 96
Engine stop
refer to Start/Stop system............. 102
Entry/exit. IQhtingie: + scsi as essen & © wonvme a v6 53
Entryiassistanee:: 2 coca 2s acim os eee 2 o were 65
also refer to Exit assistance............. 65
Environment
Unleaded gasoline.................00. 217
ESC
refer to Electronic Stabilization Control... 113
ESC Offroad... 2.1... eee eee ee 114
ESC Sport........... 000.000.0000 0000- 114
eSIM
refer to Embedded SIM card............ 174
Event Data Recorder (EDR).............. 277
Exit assistance .... 0.2... 0.00... e eee eee 65
Exit warning ...... 0.66... e ee ee eee eee 148
Exteriomantenna «cise oo srerw wane © aecete 165
Exterior Lighting’: = = sce «= seus © x cere = 4 seus 51
291