2020 AUDI A4 check engine

8W1012721BB
Trailer towing

them so you have a sufficient visibility behind
you.
Exterior lighting
Follow the legal regulations for lighting on your
trailer that are applicable in the country where
you are operating the vehicle. Contact an author-
ized Audi dealer or authorized Audi Service Facili-
ty for more information.
Before you start driving, check all lighting equip-
ment on the trailer while it is hitched to the vehi-
cle.
The headlight range control automatically ad-
justs the light range of the headlights.
Safety chains
Make sure the safety chains are correctly applied
when pulling a trailer. The chains should hang
enough so that the trailer can drive around
curves. However, they must not touch the
ground.
@) Note
Attachments retrofitted on the vehicle may
cause damage, especially on the trailer hitch
ball head. In cases of damage, have the func-
tion checked by an authorized Audi dealer or
authorized Audi Service Facility.
@) Tips
— Block the wheels with chocks when parking
on inclines if the trailer is loaded.
— Having the vehicle inspected between the
inspection intervals is recommended if you
tow a trailer frequently.
— Avoid driving with a trailer during the vehi-
cle break-in period.
Driving with a trailer
Driving with a trailer requires extra caution.
Speed
Adhere to the legal speed limits. Follow the legal
regulations that are applicable in the country
where you are operating the vehicle.
As the speed increases, the driving stability of
the trailer decreases. Therefore you should not
exceed the maximum legal speed limit when
there are unfavorable road, weather, and/or wind
conditions. This especially applies when driving
downhill.
Hill
When you start driving uphill or downhill, trailers
may tilt or sway sooner than when driving ona
level surface. If small swaying movements have
already occurred, you can stabilize the trailer by
firmly braking immediately. Never attempt to
“straighten out” the trailer by accelerating.
Downshift before driving on hills to utilize the en-
gine braking effect > A\.
Brakes
When using a trailer with overrun brakes, first
brake gently then quickly. This reduces the risk of
jerking while braking if the trailer wheels lock up.
Engine coolant temperature
Pay attention specifically to the coolant tempera-
ture display when there are high outside temper-
atures, and when driving on long inclines
=> page 13. Shift to a higher gear in a timely man-
ner.

Z\ WARNING
Constant braking causes the brakes to over-
heat and can substantially reduce braking per-
formance, increase braking distance, or cause
complete failure of the brake system.

113

Checking and Filling

Checking and Filling
Fuel
Types of gasoline
The correct gasoline grade is stated on the inside
of the fuel filler door.
The vehicle is equipped with a catalytic converter
and must only be driven with unleaded gasoline.
Audi recommends using TOP TIER Detergent Gas-
oline. For additional information on TOP TIER De-
tergent Gasoline, visit www.toptiergas.com.
The individual gasoline grades are differentiated
by octane ratings. This value is given with (R
+M)/2 equating to AKI or in RON.
The headings below match the sticker in the fuel
filler door (examples):
UNLEADED FUEL ONLY MIN. (R+M)/2 87
Regular / MIN. RON 91 Regular
Use regular gasoline with minimum 87 AKI /
91 RON > ©.
Audi recommends using premium gasoline with
minimum 91 AKI / 95 RON to achieve the rated
horsepower and torque.
UNLEADED FUEL ONLY PREMIUM MIN. (R
+M)/2 91 / SUPER MIN. RON 95
Using premium gasoline with minimum 91 AKI /
95 RON is recommended.
If premium gasoline is not available, you can also
use regular gasoline 87 AKI / 91 RON. However
this does reduce the engine power slightly.
() Note
— Filling the tank just one time with leaded
fuel or other metallic additives will cause
permanent deterioration to the catalytic
converter function.
— When gasoline with an octane rating that is
too low is used, high speeds or heavy engine
load can lead to engine damage.
210
G) Tips
The vehicle may be filled with fuel that has a
higher octane rating than what is required by
the engine.
Gasoline mixture
Gasoline with alcohol or MTBE (Methyl-Tert-
Butyl-Ether)
You can use unleaded gasoline mixed with alco-
hol or MTBE (generally labeled as oxygenated
compounds) as long as the fuel meets the follow-
ing conditions:
Gasoline with methanol content (methyl alco-
hol
or methanol)
— Anti-Knock Index is at least 87 AKI
—No more than 3% methanol
— More than 2% solvent
Gasoline with ethanol content (ethyl alcohol or
ethanol)
— Anti-Knock Index is at least 87 AKI
—No more than 15% ethanol
Gasoline with MTBE content
— Anti-Knock Index is at least 87 AKI
—No more than 15% MTBE
Gasoline adapted to the season
Many gasoline fuels are adapted to the seasons.
When the season changes, we recommend refu-
eling at high-traffic gas stations. It is more likely
that the gasoline will be suitable for the season
there.
() Note
— Gasoline with methanol content that does
not meet the specified conditions may cause
corrosion damage and damage to plastic or
rubber components in the fuel system.
— Do not use gasoline that does not meet the
specifications.
— If you are unable to find out if a specific gas-
oline mixture meets the specifications, ask
the gas station operator or their fuel suppli-
er.

8W1012721BB
Checking and Filling

— Do not use any gasoline mixture whose
composition cannot be identified.
— Audi does not assume any responsibility for
damage to the fuel system or for perform-
ance problems caused by using gasoline
mixtures different from those specified.
This type of damage also does not fall under
the New Vehicle Limited Warranty or under
the emissions control system warranty.
— If you notice a higher fuel consumption or
poor handling or performance problems due
to such gasoline mixtures, we recommend
fueling with unblended gasoline.
Gasoline additives
An important issue for many automobile manu-
facturers is combustion residue in the engine
that results from the use of certain fuels.
Although types of gasoline differ depending on
the manufacturer, there are similarities. Certain
substances in the gasoline may cause deposits in
the engine. Additives in the gasoline that should
keep the engine and fuel system clean do not all
function equally.
Audi recommends using TOP TIER Detergent Gas-
oline. For additional information on TOP TIER De-
tergent Gasoline, visit www.toptiergas.com.
If you use incorrect fuels over a long period of
time, the maximum engine performance may be
impaired by combustion residue.
@) Note
— Damage or malfunctions caused by the use
of incorrect types of gasoline are not cov-
ered by the New Vehicle Limited Warranty.
— Only gasoline additives that have been ap-
proved by Audi may be used.
Refueling
Messages
[i Tank system: malfunction! Please contact
Service

There is a malfunction in the fuel tank system.
Drive to an authorized Audi dealer or authorized
Audi Service Facility immediately to have the
malfunction corrected.
Fueling procedure
Fig. 156 Right rear side of the vehicle: opening the fuel
filler door

Fig. 157 Fuel filler door with attached fuel cap
The fuel filler door is unlocked or locked by the
central locking system.
> Unlock the vehicle if necessary.
> Press on the left side of the fuel filler door to
open it > fig. 156.
> Unscrew the tank cap counterclockwise.
> Place the cap from above on the open fuel filler
door > fig. 157.
> Insert the fuel pump nozzle all the way into the
fuel filler neck.
> Begin fueling. Once the fuel pump nozzle turns
off the first time, the fuel tank is full. Do not
continue fueling, or else the expansion space in
the tank will be filled with fuel.
> After the fuel pump has switched off, wait five
seconds before removing the nozzle to allow
the rest of the fuel to finish dripping into the
fuel tank.
211

Checking and Filling

> Turn the fuel cap clockwise until it clicks into
place.
> Close the fuel filler door and then press on the
left side until it latches.
The correct fuel type for your vehicle can be
found on a label located on the inside of the fuel
filler door. For additional information on fuel, see
=> page 210.
For the tank capacity in your vehicle, refer to the
Technical Data > page 278.
To reduce the risk of fuel leaking out or vapors
escaping, make sure that the fuel tank is closed
correctly. Otherwise the [gg indicator light will
turn on.
If the central locking system malfunctions, there
is a fuel filler door emergency release
=> page 213.


ZA\ WARNING
Improper fueling procedures and improper
handling of fuel can lead to explosions, fires,
severe burns, and other injuries.
— Do not smoke. Keep away from open flames.
— The ignition must be switched off when re-
fueling.
— Mobile devices, radio devices, and other ra-
dio equipment should always be switched
off when refueling. Electromagnetic rays
could cause sparks and start a fire.
— If you do not insert the fuel pump nozzle all
the way into the filler tube, then fuel can
leak out. Spilled fuel can ignite and start a
fire.
— Never get into the vehicle when refueling. If
there is an exceptional situation where you
must enter the vehicle, close the door and
touch a metal surface before touching the
fuel pump nozzle again. This will reduce the
risk of electrostatic discharge that can cause
flying sparks. Sparks can start a fire when
refueling.


Z\ WARNING
Transporting fuel containers inside the vehicle
is not recommended. Fuel could leak out of
the container and ignite, especially during an
accident. This can cause explosions, fires, and
injuries.
— If you must transport fuel in a fuel contain-
er, note the following:
— Always place the fuel container on the
ground before filling. Never fill the fuel
container with fuel while it is inside or on
the vehicle. Electrostatic discharge can oc-
cur while refueling and the fuel vapors
could ignite.
— When using fuel containers made of met-
al, the fuel pump nozzle must always re-
main in contact with the container to re-
duce the risk of static charge.
— Insert the fuel pump nozzle as far as pos-
sible into the filler opening while refuel-
ing.
— Follow the applicable legal regulations in
the country where you are driving when
using, storing and transporting fuel con-
tainers.
— Make sure that the fuel container meets
the industry standards, for example ANSI
or ASTM F852-86.



1) Depending on the engine and country
212
() Note
— Remove fuel that has overflowed onto any
vehicle
components immediately to reduce
the risk of damage to the vehicle.
— Never drive until the fuel tank is completely
empty. The irregular supply of fuel that re-
sults from that can cause engine misfires.
Uncombusted fuel may enter the exhaust
system and increase the risk of damage to
the catalytic converter.
@) For the sake of the environment
— Do not overfill the fuel tank, or fuel could
leak out when the vehicle is warming up.
— Fuel should never enter the sewer system or
come into contact with the ground.

8W1012721BB
Checking and Filling

@) Tips
The fuel filler door on your vehicle does not
lock if you lock the vehicle from the inside us-
ing
the central locking switch.

Fuel filler door emergency release
If the central locking system malfunctions, the
fuel filler door can be unlocked manually.

Fig. 158 Right side trim panel in the luggage compart-
ment: opening the trim panel

Fig. 159 Luggage compartment: fuel filler door emergency
release
The emergency opening mechanism is located
behind the right side trim panel in the luggage
compartment.
> Open the cover in the side panel > fig. 158.
> To unlock the fuel filler door, loosen the loop
from the retainer and then pull on the loop
carefully > fig. 159 >@).
> Press on the left side of the fuel filler door to
open it > page 211, fig. 156.
® Note
Only pull on the loop until you feel resistance.
You will not hear it release. If you continue to

pull, you could damage the emergency re-
lease mechanism.
Emissions control
system
General information
ZA\ WARNING
The temperature of the exhaust system is
high, both when driving and after stopping
the engine.

— Never touch the exhaust tail pipes once they
have
become hot. This could result in burns.
— Do not park your vehicle over flammable
materials such as grass or leaves because
the high temperature of the emissions sys-
tem could start a fire.
— Do not apply underbody protectant in the
exhaust system area, because this increases
the risk of fire.
(ele) Nidtml alg
Follow the safety precautions > page 213, Gener-
al information.

The vehicle may only be driven with unleaded
gasoline, or the catalytic converter will be de-
stroyed.
Never drive until the tank is completely empty.
The irregular supply of fuel that results from that
can cause engine misfires. Uncombusted fuel
could enter the exhaust system, which could
cause overheating and damage to the catalytic
converter.

Malfunction Indicator Lamp (MIL)
If the S indicator light blinks or turns on, there
is a malfunction that is causing poor emissions
quality and that could damage the catalytic con-
verter. Drive slowly to an authorized Audi dealer
or authorized Audi Service Facility to have the
malfunction corrected.
213

Checking and Filling

The indicator light can also turn on if the fuel fill-
er cap is not closed correctly > page 211).
Engine compartment
General information
Special care is required if you are working in the
motor compartment
For work in the motor compartment, such as
checking and filling fluids, there is a risk of in-
jury, scalding, accidents, and burns. For this
reason, follow all the warnings and general
safety precautions provided in the following in-
formation. The engine compartment is a dan-
gerous area in the vehicle. > A.


ZA WARNING
— Turn the engine off.
— Switch the ignition off.
— Set the parking brake.
— Select the “P” (Park) selector lever position.
— Allow the engine to cool.
— Keep children away from the engine com-
partment.
— Never spill fluids on a hot engine. These flu-
ids (such as the freeze protection contained
in the coolant) can catch fire.
— Avoid short circuits in the electrical system.
— Never reach into the radiator fan. The fan is
temperature-controlled and can turn on
suddenly, even when the ignition is switched
off.
— 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.
— The cap on the coolant expansion tank must
never be opened when the coolant is hot.
The cooling system is under pressure. There
is a risk of burns
—To protect your face, hands, and arms from
hot steam or coolant, cover the cap with a
— Do not remove the engine cover under any
circumstances. This increases the risk of
burns.
— Due to the risk of electric shock, never touch
the ignition cable or other components in
the electronic high-voltage ignition system
when the engine is running or is starting.
— Ifa gear is engaged while the vehicle is sta-
tionary and the engine is running, do not
press the accelerator pedal inadvertently.
Pressing the accelerator pedal will cause the
vehicle to move, and this could result in an
accident.
— If inspections or repairs must be performed
while the engine is running, moving compo-
nents (such as the ribbed belt, generator,
and radiator fan) pose an additional risk.
— Set the parking brake first and select the
“P” (Park) selector lever position.
— Always make sure that no parts of the
body, jewelry, ties, loose clothing, and
long hair can be caught in moving engine
components. Before any work, always re-
move any jewelry and/or ties, tie back long
hair, and make sure all clothing fits close
to the body to reduce the risk of anything
becoming caught in engine components.
— Pay attention to the following warnings list-
ed when work on the fuel system or on the
electrical equipment is required.
— Do not smoke.
— Never work near open flames.
— Always have a working fire extinguisher
nearby.
— 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.
— Limit your exposure to exhaust and chemi-
cals to as short a time as possible.




thick cloth when opening.


ZA\ WARNING
California Proposition 65 Warning:


1) Depending on the engine and country
214

8W1012721BB
Checking and Filling


— Engine exhaust, some of its constituents,
and certain vehicle components contain or
emit chemicals known to the State of Cali-
fornia to cause cancer and birth defects and
reproductive harm. In addition, certain flu-
ids contained in vehicles and certain prod-
ucts of component wear contain or emit
chemicals known to the State of California
to cause cancer and birth defects or other
reproductive harm.
— 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.
Q Note
When filling fluids, be sure not to add any flu-
ids to the wrong reservoirs. Otherwise severe
malfunctions and engine damage will occur.


@ For the sake of the environment
You should regularly check the ground under
your vehicle in order to detect leaks quickly. If
there are visible spots from oil or other fluids,
bring your vehicle to an authorized Audi deal-
er or authorized Audi Service Facility to be
checked.
Opening and closing the hood
The hood is released from inside the vehicle.


Fig. 160 Footwell: release lever

Fig. 161 Unlocked hood: lever
Make sure the wiper arms are not raised up from
the windshield. Otherwise the paint could be
damaged.
Opening the hood
> With the door open, pull the lever > below
the instrument panel in the direction of the ar-
row > fig. 160.
> Raise the hood slightly > /A\.
> Press the lever > fig. 161 in the direction of the
arrow. This releases the hooks.
> Open the hood.
Closing the hood
> Push the hood down until you override the
force of the struts.
> Let the hood fall lightly into the latch. Do not
press itin. > AX.
Message
B Warning! Hood is not locked. Stop vehicle
and check the lock
The hood latch is not locked correctly. Stop im-
mediately and close the hood.

ZX 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
closed securely while driving. Because of
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. >

215

Checking and Filling

- If you notice that the hood is not latched
while you are driving, stop immediately and


N
INS —
close it, because driving when the hood is
not latched increases the risk of an accident.

/( \\. |
Fig. 162 Typical location of the reservoir and the engine oil filler opening (example)
Follow the safety precautions > page 214.
Washer fluid reservoir (>) > page 225
Jump start points: (+) under the cover
=> page 225, Charging the battery
= page 260, Preparation

Engine oil filler opening (7) > page 217

) Sticker* for engine oil specification
=> page 216
Coolant expansion tank (£) > page 221
Brake fluid reservoir (O)) > page 222

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.
216
Engine oil
the engine oil level is too low
If you need to add engine oil, use an oil that is
listed on the sticker. The sticker is located at the
front of the engine compartment > page 216,
fig. 162.
If the recommended engine oil is not available, in
an emergency you may add a maximum of 1
quart (1 liter) of ACEA C3 or API SN engine oil
one time until the next oil change.
For more information on the correct engine oil
for your vehicle, contact an authorized Audi deal-
er or authorized Audi Service Facility. Have the oil
changed by an authorized Audi dealer or author-
ized Service Facility.