2020 AUDI A8 check engine

4N0012721BD
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
Fueling procedure


Fig. 177 Right rear side of the vehicle: opening the fuel
filler door
B8V-0559

Fig. 178 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.
> Conventional drive system: Press on the left
side of the fuel filler door to open it > fig. 177.
> Plug-in hybrid drive: Pull the A) button in the
driver's door. The fuel filler door will open auto-
matically after venting is complete.
> Unscrew the tank cap counterclockwise.
> Place the cap from above on the open fuel filler
door > fig. 178.
>» Plug-in hybrid drive: note the information for
refueling at the end of this chapter.
> 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 toallow >
271

Checking and Filling

the rest of the fuel to finish dripping into the
fuel tank.
> 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 ona label located on the inside of the fuel
filler door. For additional information on fuel, see
=> page 270.
For the tank capacity in your vehicle, refer to the
Technical Data > page 342.
To reduce the risk of fuel leaking out or vapors
escaping, make sure that the fuel tank is closed
correctly. Otherwise the Ey indicator light will
turn on.
If the central locking system malfunctions, there
is a fuel filler door emergency release
=> page 273.
Messages
Al 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.
Messages
Applies to: vehicles with plug-in hybrid drive
Ay Fuel filler door: malfunction! Unlock fuel
filler door manually. See owner's manual
There is a malfunction. You must manually un-
lock the fuel filler door > page 273.
Al Warning! Vehicle performance may be limit-
ed
The fuel tank is almost empty. You must antici-
pate a significant power loss. Refuel immediate-
ly.
Ay Fuel filler door open. Please press button
again to refuel

1) Depending on the engine and country
272
Fueling is possible for a little while after pressing
the fl} button. You must press the ff) button
again if the time limit is exceeded.

Z\ 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.

ZA\ 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.

Checking and Filling



— When using fuel containers made of met- — You must vent the tank system again if you
al, the fuel pump nozzle must always re- press on the fuel filler door opener. The fuel
main in contact with the container to re- pump nozzle can stay in the fuel filler neck
duce the risk of static charge. when doing this. Vent the tank system by
— Insert the fuel pump nozzle as far as pos- pulling the E) switch in the driver's door
sible into the filler opening while refuel- again.
ing. — If the engine turned off because the fuel
— Follow the applicable legal regulations in level was too low, then you may need to re-
the country where you are driving when fuel with up to 4.0 gallons (15 liters) of fuel
using, storing and transporting fuel con- in order for the vehicle to detect the new
tainers. fuel level. Otherwise, the engine may not
— Make sure that the fuel container meets restart.
the industry standards, for example ANSI — Fuel can age and may lead to problems
or ASTM F852-86. when starting. Audi recommends replacing

4N0012721BD
the fuel in your vehicle within six months.
@) Note
— Remove fuel that has overflowed onto any Fuel filler door emergency release
vehicle components immediately to reduce Applies to: vehicles with manual fuel filler door release
the risk of damage to the vehicle. If the central locking system malfunctions, the
— Never drive until the fuel tank is completely fuel filler door can be unlocked manually.
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.
@ 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.
G@) Tips
Applies to: vehicles with plug-in hybrid drive


Fig. 179 Right cover in the luggage compartment: remov-
ing the cover
— When inserting the fuel pump nozzle, make
sure that you do not press on the fuel filler
door opener @) with the fuel pump nozzle.



Fig. 180 Luggage compartment: fuel filler door emergency
release
See the label in the fuel filler door @)
> fig. 178. Otherwise, a valve will close in The emergency opening mechanism is located
the fuel filler neck and fueling will stop even behind the right cover in the luggage compart-
if the tank is not full. ment.
273

Checking and Filling

> Remove the screwdriver from the vehicle tool
kit > page 316.
> Carefully insert the flat side of the screwdriver
from below into the center of the top slot in the
cover > fig. 179.
> Use the screwdriver to pull the cover toward the
center of the vehicle and remove the cover.
> To unlock the fuel filler door, loosen the red
loop from the retainer and then pull on the
loop carefully > fig. 1802 ©.
> Press on the left side of the fuel filler door to
open it > page 271, fig. 177.
@ 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.
@ Tips
Applies to: vehicles with plug-in hybrid drive
— The tank will not be vented if the emergency
release function was used on the fuel filler
door. You can only fill a small amount of
fuel in the tank. Fill only until the fuel pump
nozzle turns off for the first time. Drive to
an authorized Audi dealer or authorized
Audi Service Facility immediately to have
the malfunction corrected.
— Pressure can escape if you open the tank cap
after using the emergency release. This can
create noises.
Emissions control
system
General information
Z\ 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.



1) Depending on the engine and country
274

— 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.
Catalytic converter
Follow the safety precautions > page 274, 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 [J 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.
The indicator light can also turn on if the fuel fill-
er cap is not closed correctly page 271).
Engine compartment
General information
Special care is required if you are working in the
engine compartment
For work in the engine 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 >

4N0012721BD
Checking and Filling

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.
— Plug-in hybrid drive: the coolant expansion
tank cap is equipped with a seal that must
never be removed under any circumstances
= page 277, fig. 183. If the coolant expan-
sion tank for the high-voltage system is not
sealed, please contact an authorized Audi
dealer or authorized Audi Service Facility.
— Plug-in hybrid drive: the sealed cap must on-
ly be opened by an authorized Audi dealer or
authorized Audi Service Facility.
— 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
thick cloth when opening.
— 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.


ZA\ WARNING
California Proposition 65 Warning:
— 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

275

Checking and Filling


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.
o 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. 181 Footwell: release lever (example)

RAZ-0016,

Fig. 182 Unlocked hood: lever
276

Make sure the wiper arms are not raised up from
the windshield. Otherwise the paint could be
damaged.
Opening the hood
> Applies to: vehicles with plug-in hybrid drive:
Switch the ignition off before releasing the
hood so that the gasoline engine does not start
automatically.
> With the door open, pull the lever > below
the instrument panel in the direction of the ar-
row > fig. 181.
» Raise the hood slightly > page 274.
> Press the lever > fig. 182 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 strut.
> Let the hood fall lightly into the latch. Do not
press it in. > /\.
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.

Z\ 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
latched 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.
— If you notice that the hood is not latched
while you are driving, stop immediately and
close it, because driving when the hood is
not latched increases the risk of an accident.

4N0012721BD
Checking and Filling
Engine compartment overview
The most important check points.




Fig. 183 Typical location of the reservoir and the engine oil filler opening (example)
Follow the safety precautions > page 274. G) Tips
@ Washer fluid reservoir (6) > page 287 Plug-in hybrid drive*: read the information re-
@ Jump start point (+) under a cover, (-) with garding the coolant expansion tank under
hex head screw > page 286, Charging the 12 => page 282 and the jump start under >@® in
Volt vehicle battery, > page 322, Jump start- Preparation on page 323.
ing
® Engine oil filler opening (387) 9 page 279 Engine oil
@ Brake fluid reservoir (O)
under a cover
© page 283
© Coolant expansion tank for combustion en- If you need to add engine oil, use an oil that is
gine (4) > page 282 listed on the sticker. The sticker is located at the
© Plug-in hybrid drive: coolant expansion tank front of the engine compartment > page 277,
for the high-voltage system ( page 282 fig. 183.
@ Sticker* for engine oil specifications
If the recommended engine oil is not available, in
=> page 277
an emergency you may add a maximum of 1
The engine oil filler opening may be located ina quart (1 liter) of ACEA C3 or API SN engine oil
different area depending on the specific engine. one time until the next oil change.
For more information on the correct engine oil
for your vehicle, contact an authorized Audi >
277

Checking and Filling

dealer or authorized Audi Service Facility. Have
the oil changed by an authorized Audi dealer or
authorized Service Facility.

Audi recommends
Slastrol) (ZDIGE Prorzssional
Audi recommends using the LongLife high-per-
formance engine oil from Audi Genuine Parts.
WEE Tel
Engine oil pressure


=] Turn off engine. Oil pressure too low
Stop driving and switch the engine off. Check the
engine oil level > page 278.
— If the engine oil level is too low, add engine oil
=> page 279. Only continue driving once the in-
dicator light turns off.
— If the engine oil level is correct and the indica-
tor light still turns on, turn the engine off and
do not continue driving. See an authorized Audi
dealer or authorized Audi Service Facility for as-
sistance.
Engine oil level
= Please add oil immediately
Stop driving and switch the engine off. Check the
engine oil level > page 278 and add engine oil
immediately > page 279.
3 Add max. x qt (x J) oil. You can continue
driving
Add the amount of oil shown immediately
=> page 279.
Reducing the oil level
3 Please reduce oil level
There is too much oil in the engine and there is a
risk of damaging the catalytic converter or en-
gine. Drive to an authorized Audi dealer or au-
thorized Audi Service Facility immediately to have
engine oil extracted if necessary. Avoid high en-
gine speeds, full acceleration, and heavy engine
loads.
278
Engine oil sensor
=) Oil level sensor: oil change necessary. Please
contact Service
Fuel has entered the engine oil. This will cause
the engine oil level to rise slowly and the engine
oil quality to decrease. Do not extract engine oil
to reduce the level, because this will increase the
risk of engine damage. Drive to an authorized
Audi dealer or authorized Audi Service Facility im-
mediately to have engine oil extracted.
& Oil level system: malfunction! Please con-
tact Service
The sensor that checks the engine oil level has
malfunctioned. Drive immediately to an author-
ized Audi dealer or authorized Audi Service Facili-
ty to have the malfunction repaired.
2 Oil pressure sensor: malfunction! Please
contact Service
The sensor that checks the engine oil pressure
has malfunctioned. Drive immediately to an au-
thorized Audi dealer or authorized Audi Service
Facility to have the malfunction repaired.
Engine warm-up request
i Please drive to warm up engine
Fuel has entered the engine oil, either due to low
outside temperatures or frequent short drives.
Drive until the engine is warm so that the fuel in
the engine oil will evaporate. Avoid high engine
speeds, full accelerating, and heavy engine loads
when doing this.
@) Tips
The oil pressure warning B is not an oil level
indicator. Always check the oil level regularly.
Checking the engine oil level
The engine oil level can be checked in the MMI.
Follow the safety precautions > A\ in General in-
formation on page 275.
> Park the vehicle on a level surface.
> Shut the engine off when it is warm.
> Switch only the ignition back on.