2021 AUDI A8 overheating

Instrument cluster

Reducing the display
Depending on the vehicle equipment, you can
hide the central area in the instrument cluster.
> Select on the instrument cluster: vehicle func-
tions tab > E] button > Reduced display.
Coolant temperature
display
Applies to: vehicles with a coolant temperature indicator
The coolant temperature display @ > page 12
only functions when the ignition is switched on.
To reduce the risk of engine damage, please ob-
serve the following notes about the temperature
ranges.
Cold range
If only the LEDs at the bottom of the gauge turn
on, the engine has not reached operating tem-
perature yet. Avoid high engine speeds, full accel-
eration, and heavy engine loads.
Normal range
The engine has reached its operating tempera-
ture once the LEDs up to the center of the gauge
turn on. If the | indicator light in the instru-
ment cluster display turns on, the coolant tem-
perature is too high > page 281.
@) Note
— Auxiliary headlights and other accessories in
front of the air intake impair the cooling ef-
fect of the coolant. This increases the risk of
the engine overheating during high outside
temperatures and heavy engine load.
— The front spoiler also helps to distribute
cooling air correctly while driving. If the
spoiler is damaged, the cooling effect will
be impaired and the risk of the engine over-
heating will increase. See an authorized
Audi dealer or authorized Audi Service Fa-
cility for assistance.
Tachometer
The tachometer (@) 9 page 12 displays the engine
speed in revolutions per minute (RPM). The be-
ginning of the red zone in the tachometer indi-
14
cates the maximum permissible engine speed for
all gears once the engine has been broken in. Be-
fore reaching the red zone, you should shift into
the next higher gear, select the "D" or "S" selec-
tor lever position, or remove your foot from the
accelerator pedal.
Displaying the tachometer
Applies to: vehicles with plug-in hybrid drive
> Applies to: MMI: Select on the home screen:
SETTINGS > Display & brightness > Audi virtu-
al cockpit > Left dial > Tachometer or Com-
bined.
Engine speed limitation
If the Bw indicator light turns on, the engine will
be automatically limited to the RPM displayed in
the instrument cluster. This will protect the en-
gine components, for example during a cold start
or from overheating.
The engine speed limitation is deactivated if you
release the accelerator pedal while the engine is
at normal operating temperature.
If the engine speed limitation was activated by
an engine control malfunction, the indicator
light also turns on. Make sure the engine speed
does not go above the speed displayed, for exam-
ple when downshifting. Drive to an authorized
Audi dealer or authorized Audi Service Facility im-
mediately to have the malfunction corrected.
C) Note
The needle in the tachometer may only be in
the red area of the gauge for a short period of
time before there is a risk of damaging the
engine. The location where the red zone be-
gins varies depending on the engine.

High-voltage system

G) Tips
Applies to: Audi charging systems
— For an uninterrupted charging process, we
recommend only charging using sockets
that are connected to a separately protected
circuit.
— It is recommended to use Audi charging sys-
tems in the wall mount clip* during opera-
tion. If this is not possible, always position
Audi charging systems ona secure surface
during the charging process > A\.
—To reduce the risk of overheating during op-
eration, do not place Audi charging systems
in direct sunlight for long periods of time. If
the control unit is overheated, the charging
Process is automatically paused until the
temperature has lowered back within the
normal range.
Charging
Applies to: vehicles with plug-in hybrid drive

RAZ-0834


ss

Fig. 99 Left rear side of the vehicle: opening the high-volt-
age charging port door

RAZ-0835



Fig. 100 Charging unit: charging port and buttons/LED
Connecting the charging cable
If you charge your vehicle at a charging station,
the following sequence of steps may vary. Follow
134
the manufacturer guidelines and operating in-
structions for the charging station.
Requirement: the “P” gear must be selected, the
parking brake must be set, and drive ready mode
must have ended.
—If necessary, remove the charging cable from
the vehicle > page 139, Transport.
— Remove the cap from the charging cable if nec-
essary.
— First connect the charging cable to the power
supply, or remove it from the charging station.
— Unwind the charging cable completely.
— Unlock the vehicle.
—To open the charging port door, press on the
right
side of the door > fig. 99.
— Remove the cap from the vehicle charging port
and place it on the holder on the charging port
door.
— Plug the charging connector into the vehicle
charging port.
— Check if the charging option shown @) (immedi-
ate charging/timer charging) is the one you
would like to use for charging.
Starting to charge automatically (immediate
charging)
If charging is not delayed with a timer, the charg-
ing process will begin immediately. If necessary,
the charging station may need to be activated.
Follow the manufacturer guidelines and operat-
ing instructions for the charging station.
Timer charging
With timer charging, the charging process starts
and ends based on a timer that is set beforehand.
— To charge by timer, switch on the timer and
timer charging before exiting the vehicle
=> page 136.
While charging
The charging display on the charging unit @) will
pulse green while charging. It will pulse |} in
the instrument cluster. You can find the meaning
of the possible charging display colors under
> page 135.
The charging connector is locked while charging
and cannot be removed.

High-voltage system

Audi e-tron compact charging system
Applies to: vehicles with Audi e-tron compact charging system

a oho


RAZ-0726}


Fig. 104 Audi e-tron compact charging system: compo-
nents (example)
Observe the safety precautions > page 132, Im-
portant safety precautions.
The Audi e-tron compact charging system can be
used for charging with a household or industrial
socket. Depending on the country and the vehicle
equipment, the following accessories may be
available:
@ Control unit
@ Vehicle cable with vehicle charging connector
@) Power cable with power plug for household
sockets
@ Power cable with power plug for industrial
sockets
The vehicle cable is securely connected to the
control unit. The power cable is plugged into the
upper end of the control unit and can be switched
=>page 145.
Control unit overview

© | On/Off button @, charging power lev-
el and LED
© _ |Status LED:
a Power supply/household
connection
& | Vehicle
0 Control panel
@ 9
Charging




Reset

Note the instructions for charging > page 134.
140
Fig. 105 Audi e-tron compact charging system: control
unit
Requirement: the correct power plug must be in-
stalled > page 145.
— Insert the plug into the socket.
— Plug the vehicle charging connector into the ve-
hicle charging port.
— The charging process e will start automatically.
— Once the charging process has completed, un-
lock the vehicle and remove the vehicle charg-
ing connector from the vehicle charging port.
Adjusting the charging power level
The control unit automatically recognizes the
voltage and the available current strength. You
can set whether you would like to charge with full
or reduced charging power. The last setting that
was selected will be saved and used again the
next time the vehicle is charged. If multiple
items are connected to the power circuit, the
charging current may be reduced when charging
at a power outlet. This can help to prevent the
electrical equipment from overheating.
Before charging, always check if the charging
power setting that was selected last is still suita-
ble.
—To set the charging power level, press and hold
the ® button © © fig. 105 for at least two sec-
onds.
After the charging power level is set, the status
LEDs (, and [) will flash green one time. The
selected value (50% or 100%) is displayed on the
left or right side of the ® button.

4N0012721BF
Driver assistance

Driver assistance
Cruise control system
Applies to: vehicles with cruise control system
The cruise control system assists the driver in
maintaining a constant speed above approxi-
mately 15 mph (20 km/h). The system maintains
the desired speed by braking and accelerating.
Switching the system on
Applies to: vehicles with cruise control system


ZA WARNING
— Always pay attention to the traffic around
your vehicle when the cruise control system
is in operation. As the driver, you are always
responsible for controlling your vehicle
speed and the distance between your vehicle
and
other vehicles.
— For safety reasons, cruise control should not
be used in the city, in stop-and-go traffic, on
winding roads, and when road conditions are
poor (such as ice, fog, gravel, heavy rain,
and conditions that could lead to hydroplan-
ing), because this increases the risk of an ac-
cident.
— Switch the cruise control off temporarily
when driving in turning lanes, highway exits,
or in construction zones.
—To reduce the risk of an accident, you should
only resume the stored speed if it is suitable
for the current traffic conditions.
BFV-0220



() Note
— Conventional drive system:Before driving
downhill a long distance on a steep hill, de-
crease your speed and select a lower gear.
This makes use of the engine braking effect
and reduces the load placed on the brakes.
— Plug-in hybrid drive: Before driving downhill
a long distance on a steep hill, decrease
your speed and use the recuperation braking
effect > page 114. This reduces the load on
the brakes.
@ Tips
The brake lights turn on when the brakes are
applied automatically.


Fig. 116 Operating lever: switching the system on
Requirement: the ignition must be switched on.
> To switch the system on, pull the lever toward
you to position ©.
The Gia or i$) indicator light and the corre-
sponding message will appear in the instrument
cluster.

ZA\ WARNING
If the brakes are malfunctioning (for example,
overheating) while the cruise control system
is switched on, the regulating functions may


shut off automatically.


Preselecting or activating a cruise con
speed
Applies to: vehicles with cruise control system
When the vehicle is stationary, you can preselect
the cruise control speed or activate the speed
while driving.
Requirement: the system must be switched on.
> To preselect a cruise control speed when the ve-
hicle is stationary, tap the lever toward @)/G)
=> page 163, fig. 116.
> To activate the cruise control speed, pull the
lever
toward position @ while driving.
> To set the current driving speed as the cruise
control speed, press the button @) on the lever.
The active cruise control speed is indicated with
the Gg or kl indicator light in the instrument
cluster.
163
>

Driver assistance

An additional indicator will appear in the head-up
display*.
Changing the cruise control speed
Applies to: vehicles with cruise control system
Requirement: the system must be switched on.
> To increase or decrease the cruise control speed
in small increments, tap the lever up to the
first level toward @)/G) 9 page 163, fig. 116.
> To increase or decrease the cruise control speed
in larger increments, tap the lever up to the
second level toward @)/G).
> To increase or decrease the cruise control speed
continuously, tap and hold the lever at the first
or second level toward @)/G).
Overriding or deactivating the cruise
control speed
Applies to: vehicles with cruise control system
You can override or deactivate the cruise control
system. When you deactivate the system, your
cruise control speed will be stored and you can
resume that speed.
Requirement: the system must be switched on
and the regulated speed must be activated.
Overriding
> To temporarily override the cruise control
speed, press the accelerator pedal.
> To resume the stored regulated speed, remove
your foot from the accelerator pedal.
If you override the cruise control system for a
long period of time, the cruise control system
will be deactivated. The [Ud or [RM indicator
light will be displayed and the cruise control
speed will be saved.
Deactivating
> To deactivate the cruise control speed, press
the lever toward @) (not locked into place)
=> page 163, fig. 116, or
> Press the brake pedal.
164

ZA WARNING
Resting your foot on the accelerator pedal
could override the cruise control. This will pre-
vent braking interventions by the system.
See me Lai
Applies to: vehicles with cruise control system

When you switch the system off, the cruise con-
trol speed will be erased.
Requirement: the system must be switched on.
> To switch the system off, press the lever toward
@ (locked into place) > page 163, fig. 116, or
> Switch the ignition off.
Applies to: vehicles with cruise control system
Gir / 3) Speed control system: currently un-
available. See owner's manual
If the indicator light turns on and this message
appears, the cruise control system has been deac-
tivated. There is a temporary malfunction, for ex-
ample the brakes are overheating. Switch the
cruise control system on again later.
Efficiency assist
Applies to: vehicles with efficiency assist
Efficiency assist can assist the driver with predic-
tive information in order to reduce fuel consump-
tion. Depending on vehicle equipment, the sys-
tem may access data from the navigation system,
the camera behind the windshield, and the radar
sensors.
Adjusting the efficiency assist
You can adjust efficiency assist functions individ-
ually. The settings depend on the vehicle equip-
ment.
— Accelerator pedal feedback > page 111.
— Interactive accelerator > page 111.
— Predictive messages > page 165.
— Predictive control > page 174, Adjusting the
adaptive cruise assist.

Checking and Filling

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.
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
safety precautions provided in the following in-
formation. The engine compartment is a dan-
gerous area in the vehicle. > A.
Explanation of warnings (sticker in the engine
compartment):
®

Hot engine components!
Rotating parts!

The catalytic converter can be damaged
"127i if the oil level is too high!

Always follow the instructions in the op-
oA erating manual.



The radiator fan can switch on at any
i, time!

High voltage! Switch off the engine be-
5 fore coming into contact with any igni-
tion system components!



Applies to: vehicles with plug-in hybrid
drive: High voltage! The voltage in the
high-voltage system is high enough to
EN cause fatal injuries. Touching a damaged
high-voltage component can result in a
fatal electric shock.


D_ Depending on the engine and country
274

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. 181. 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
only 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.

4N0012721BF
Checking and Filling

> Push the release button again and remove the
cap completely.
> Add coolant mixed in the correct ratio
=> page 281 up to the MAX marking.
> Make sure that the fluid level remains stable.
Add more coolant if necessary.
> Turn the cap to the right to tighten it until you
feel resistance a second time.
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.

der any circumstances > page 277, fig. 181.
If the coolant expansion tank for the high-
voltage system is not sealed, please contact
an authorized Audi dealer or authorized
Audi Service Facility.
— When adding coolant, it may leak into the
inside of high-voltage components and
cause a short circuit, increasing the risk of

fire.


ZA 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 274, 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.
CG) 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|




ZA WARNING
Applies to: vehicles with plug-in hybrid drive
The coolant expansion tank for the high-volt-
age system may only be opened or filled by an
authorized Audi dealer or authorized Audi
Service Facility.
— The coolant expansion tank cap is equipped
with a seal that must never be removed un-


Fig. 184 Engine compartment: cap on brake fluid reservoir
Observe the safety precautions > page 274, Gen-
eral information.
Checking the brake fluid level
> Slide the cover that is located below the wind-
shield wipers on the driver's side toward the
windshield and remove the cover.
> Read the brake fluid level on the brake fluid res-
ervoir > page 277, fig. 181. The brake fluid lev-
el must be between the MIN and MAX markings
oA.
The brake fluid level is monitored automatically.
Messages
EG 7 @ Brakes: stop vehicle and check brake
fluid level
283
>

4N0012721BF
Checking and Filling

should only be performed by an authorized Audi
dealer or authorized Audi Service Facility > A\.
Multiple batteries with different technologies
may be installed in your vehicle:
— Vehicle battery (for example, for starting the
engine, basic power supply) > page 285, 12
Volt vehicle battery or > page 286, Other bat-
tery types
— Auxiliary battery (for example, for recuperation
or optional equipment) > page 286, Other bat-
tery types
— Plug-in hybrid drive: High-voltage battery (for
example, for electric driving) > page 131, In-
troduction.
Not running the vehicle for long periods of
time
The battery will gradually drain if the vehicle
does not run for long periods of time. To ensure
that the vehicle can still be started, the electrical
equipment will be limited or switched off. Some
convenience functions, such as interior lighting
or power seat adjustment, may not be available
under certain circumstances. The convenience
functions will be available again when you start
the
engine.
Even when electrical equipment is switched off,
the equipment can still drain the battery if the
vehicle is not driven for long periods of time.
Deep draining results in a chemical reaction that
destroys the inside of the battery. The battery
must be charged every month to prevent this
= page 286. Contact an authorized Audi dealer or
authorized Audi Service Facility for more infor-
mation.
Winter operation
Cold weather places an especially high load on
the 12 Volt vehicle battery. Have the battery
checked by an authorized Audi dealer or author-
ized Audi Service Facility before cold weather be-
gins.

this, all work must be performed only by an
authorized Audi dealer or authorized Audi
Service Facility.
— Never connect a charging cable or jump
start cable directly to the 12 Volt vehicle
battery. Only use the connections in the en-
gine compartment > page 286.

Z\ WARNING
California Proposition 65 Warning:
— 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.
@) Note
— If the vehicle will be parked for long periods
of time, protect the battery against the cold
so that it will not be destroyed by “freezing”
=> page 286, Charging the 12 Volt vehicle
battery.
— There are electrical components under the
cargo floor behind a trim panel that warm
up during operation. To reduce the risk of
the components overheating, do not store
objects such as blankets under the cargo
floor. If the components overheat, they will
switch off temporarily. This will be indicated
by a message that will be displayed in the
instrument cluster until the temperature re-
turns to normal.
12 Volt vehicle battery
Explanation of warnings:


Always wear eye protection.

Battery acid is highly corrosive. Always
wear protective gloves and eye protection.

Fire, sparks, open flame, and smoking are
forbidden.

Z\ WARNING
— All work on the battery or electrical system
in your vehicle can result in injuries, chemi-
cal burns, accidents, or burns. Because of

A highly explosive mixture of gases can
form when charging batteries. >
@
>
©

285