ignition AUDI A8 2015 Repair Manual

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temperature. This determines the current
state of charge and the power of the battery.
Idling current management
Idling current management reduces energy
consumpt ion while the vehicle is stand ing.
With the ignition switched off, it contro ls the
energy supply to the various e lectrica l compo ­
nents . Data from battery diagnosis is consid­
ered.
D epending on the battery's state of charge,
individua l consumers are gradua lly turned off
to prevent excessive discharge of the battery
and thus maintain starting capability.
Dynamic energy management
While the veh icle is being driven, dynamic en­
ergy management dist ributes the energy gen­
erated according to the needs of the individu­
a l components . It reg ulates consumption, so
that more electrical energy is not being used
than is being generated and ensures an opti­
mal state of charge for the battery.
- But even energy management cannot
negate the limits of physics. Consider
that the power and life of a battery are
limited.
- If starting ab ility is threatened, the indi­
cator light (•) appears
c> page 16, Cl
Battery .
What you should know
The highest priority is given to maintaining
starting capability .
The battery is severely taxed in short-distance
driving, in city traffic and during the cold time
of year. Abundant electrical energy is re­
qu ired, but only a little is generated. It is also
cr itica l if the engine is not running and electri­
cal components are turned on. In th is in­
stance energy is being consumed but none is
be ing generated .
Intelligent technology 203
It is in precisely these situations that you will
notice energy management active ly regu lat­
ing the distribution of energy.
Vehicle stands for an extended period
If you do not drive your vehicle over a period
of several days or weeks, e lectrica l compo­
nents are gradually cut back or switched off.
This reduces energy consumption and main­
tains starting capability over a longer period.
Some of the convenience functions may not
operate, such as the interior lights or the
power seat adjustment. The convenience
functions will be available again when you
switch on the ignition and start the eng ine.
With the engine turned off
If you listen to the radio, for example, with
the engine turned off or use other MMI func­
tions, the battery is being discharged.
If starting capability is jeopardi zed due to en­
ergy consumption , the following warning ap­
pears in the MM I display:
Please start the engine soon or the system
will be turned off.
The warning indicates that the system will be
turned off automatically after 3 minutes. If
you w ish to continue using the functions, you
have to start the engine.
With the engine running
Although electrical energy is generated when
the vehicle is being driven, the battery can be­
come discharged . This happens mostly when
li ttle energy is being generated and a great
deal consumed and the battery's state of
charge is not optimal.
T o b ring the energy ba lance back into equili­
brium , consumers wh ich requ ire espe cially
large amounts of energy are temporarily cut
back or switched off . Heating systems in par­
ticular require a great deal of energy. If you
notice, for examp le, that the heated seats* or
the heated rear window are not heating, they
have been temporarily cut back or switched .,.
•
•

206 Driving and en vir onm ent
Catalytic converter
Appl ies to vehicles: with gasoline e ngin e
It is very important that your emission con­
trol system (catalytic converter) is function­
ing properly to ensure that your vehicle is run­
ning in an environmentally sound manner .
.. Always use lead-free gasoline i=> page 220,
Fuel supply .
.. Never run the tank down all the way to emp-
ty .
.. Never put too much motor oil in your engine
¢ page 234, Adding engine oil .. Never try to push- or tow-start your veh icle.
The catalytic converter is an eff ic ient "clean­
up" device built into the exhaust system of
the vehicle. The catalyti c converter burns
many of the pollutants in the exhaust gas be­
fore they are released into the atmosphere.
The exclus ive use of unleaded fuel is cr itically
important for the l ife of the cata lytic convert­
e r and proper functioning of the engine.
A WARNING
T he 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 or operate the vehicle in
areas where the hot exhaust system may
come in contact with dry grass, brush,
fuel spill or other material which can
cause a fire.
- Do not apply additional undercoating or
rustproofing on or near the exhaust
man ifold, exhaust p ipes, catalytic con­
verter or heat shields . During driving, the
substance used for undercoating cou ld
overheat and cause a fire.
@) Note
- Be aware that just one tank f illing with
leaded fuel will al ready seriously de­
grade the perfo rmance of the cata lytic
conve rter. -
Do not exceed the correct engine oil level
i=>page 234.
-Do not drive until the fue l tank becomes
completely empty . The engine co uld m is­
fire . Unburned fuel could also get into
the exhaust system and this cou ld cause
the catalytic converter to overheat.
- Do not switch off the ignition while the
vehicle is mov ing .
- Do not continue to ope rate your vehicle
under these conditions, as otherwise fuel
can reach the catalyt ic converter. Th is
cou ld result in overheating of the con­
verter, requir ing its replacement .
- To assure efficient operation of the Emis­
sion Control System:
- Have you r vehicle maintained p roperly
and in accordance w ith the service rec­
ommendations in your Warranty & Maintenance book let.
- Lack of prope r maintenance as we ll as
improper use of the vehicle wi ll impair
the function of the em ission contro l
system and could lead to damage.
@) For the sa ke of the en vironment
Even when the Emission Control System is
ope rat ing properly, the exhaust gas can
have a sulfur-like exhaust gas smell under
some operat ing states. This depends on
the sulfur content of the fuel being used .
Usi ng a different brand of fuel may help,
or f illing the tank with lead-free super
grade gasoline.
Diesel particulate filter
Applies to vehicles: with diese l eng ine
The diesel part icu late filter filters nearly all of
the soot pa rticles out of the exhaust . T he fil­
te r cleans itself automat ica lly unde r no rma l
dr iv ing cond itions . If the filte r cannot clean it­
self (for example, because you are on ly driving
short distances), the filter becomes clogged
with soot and the
Cl symbol for the diese l
particulate filter i lluminates
i=> page 21. ..,.

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You must drive your vehicle about 3,000 miles (5,000 ki lometers) before you can properly
assess o il consumption.
This also applies to fuel consumption and en­
gine output.
(D Note
- Have yo ur vehicle maintained properly
and in accordance with the service rec­
ommendations in your Warranty
& Main­
tenance booklet. Lack of proper mainte­
nance as well as improper use of the ve­
hicle will impair the funct ion of the
emission control system and could lead
to damage .
- Do not alter or remove any component of
the Em ission Control System unless ap­
proved by the manufacturer.
- Do not alter or remove any dev ice, such
as heat shields, switches, ignition wires,
valves, wh ich are designed to protect
your vehicle's Emission Control System
and other important veh icle compo­
nents.
Fewer short trips
Fuel consumption will always be relatively
high on short trips .
.,. Try to avo id driving short distances with a
cold engine .
The engine and catalyt ic converter have to
reach their optimal
operating temperature to
reduce fuel consumption and noxious emis­
sions effect ively.
Just after starting, a cold engine in a mid-size
car only achieves a fuel economy of 6 -8 miles
per gallon (30-40 l/100 km). After about a
half a mile, fuel economy climbs to 12 mpg
(20 l/100 km). Afte r abo ut
2.5 m iles (4 km),
the eng ine is at its proper operating tempera­
ture and fue l economy has reached a normal
l eve l. So you can see that you should avoid
short trips whenever possible.
Driving and environment 209
The outside temperature is also critical in this
regard . Your car consumes more fue l in the
winter than in the summer.
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Vehicl e ca re a nd cl eanin g 215
Rinse the vehicle thoroughly with water. Then
clean using a neutral shampoo and a soft mi­
crofiber cloth.
Rinse the vehicle tho roughly again and let it
air dry. Remove any water residue using a
shammy .
A WARNING
-Only wash the vehicle when the ignition
is off and follow the instructions from
the car wash operator to reduce the risk
of accidents .
- To reduce the risk of cuts, protect your­
self from sharp metal components when
wash ing the underbody or the inside of
the wheel housings .
- After washing the vehicle, the braking ef­
fect may be delayed due to mo isture on
the brake rotors or ice in the winter. The
brakes must be dried first with a few
careful brake applicat ions.
- If you wash the vehicle in an automatic car wash, you must fold the exterior m ir­
rors in to reduce the r is k of damage to
the mirrors. Power folding exterior m ir- rors* must only be fo
lded in and out us­
ing the power folding fu nction .
- T o prevent paint damage, do not wash
the vehicle in direct sunlight.
- T o reduce the r is k of damage to the sur­
face, do not use insect removing spong ­
es, kitchen sponges or similar items.
- Matte finish painted vehicle compo­
nents:
- To reduce the risk of damage to the
surface, do not use polishing agents or hard wax.
- Never use car wash cycles that apply
protective wax. It can destroy the
matte fin ish effect .
- Do not place any stickers or magnet ic
signs on vehicle parts painted w ith
matte fin ish paint. The paint cou ld be
damaged when the stickers o r magnets
a re removed.
@ For the sake of the environment
Only wash the vehicle in facilities spec ially
designed for that p urpose . This will red uce
the r is k of dirty wate r contam inated with
oil from entering the sewer system.
Cleaning and care information
When clea ning and caring for individual vehi­
cle components, refer to the fo llow ing tab le.
The information contained there is simp ly rec ­
ommendations. For questions or for compo -nents that are not listed
, refer to a n author­
ized Audi dea ler or a qualified workshop. Also
follow the information found in ¢ .&. .
Cle an ing exte rior
Component Situation Solution
Wipe r blades
Dirty ~ page 54, Cleaning windshield wiper blades
Headlight s/ Dirty Soft sponge with a mild soap solutiona>
tail ligh ts
S en sor s/
Dirty Sensors: soft cloth with a so lvent-free cleaning product
camera le nse s Camera lenses: soft cloth with an alcohol-free cleaning
so lution
Snow/ice Hand brush/so
lvent-free de-icing spray
Wheel s Road salt Water
Brake dust Acid-free special cleaning
solution
•
•

Refuelling
Fig. 190 Right rear vehicle sid e: Opening t he fuel filler
flap
Fig. 191 Fu el filler flap with attached fuel cap
When activating the central locking, the fuel
filler flap is automatically unlocked or locked.
Refuel the vehicle with the ignition switched
off.
Taking the fuel cap off
• Press the left side of the fuel filler flap to
open it¢
fig. 190 -arrow- .
• Unscrew fuel filler cap counter-clockwise
and hang it on the fuel filler flap
r;, fig. 191.
• Check the label on the inside of the fuel fill­
er flap to determine if the vehicle must be
fueled with gasoline or diesel fuel.
Refuelling procedure
• Insert the fuel nozzle from the gasoline
pump into the fuel filler neck as far as it will
go.
• Select a medium refuelling rate so that the
nozzle switches off automatically when the
tank is full.
Putting the fuel cap back on
• After filling your tank, twist the fuel filler
cap clockwise as far as it will go.
• Close the fuel filler flap.
Fuel supply and filling your fuel tank 223
To avoid fuel spilling or evaporating from the
fuel tank always close fuel filler cap properly
and completely. An improperly closed fuel fill­
er cap may also cause the MIL lamp¢
page 29
to come on (only vehicles with gasoline en­
gine).
A WARNING
-
Improper refueling or handling of fuel can
cause fire, explosion and severe burns.
- Fuel is highly flammable and can cause
severe burns and other injuries.
- Failure to shut the engine off while refu­
eling and/or to insert the pump nozzle
fully into the fuel filler neck could cause
fuel to spray out of filler neck or to over­
flow. Fuel spray and overflowing fuel can
cause a fire.
- Never use a cellular telephone while re­
fueling. The electromagnetic radiation
can cause sparks that can ignite fuel va­
pors and cause a fire.
- Never get back into your vehicle while re­
fueling. If in exceptional circumstances
you must get back in your vehicle while
refueling, make certain that you close
the door and touch metal to discharge
static electricity before touching the fill­
er nozzle again. Static electricity can
cause sparks that can ignite fuel vapors
released during refueling .
- Never smoke or have an open flame any­
where in or near your vehicle when refu­
eling or filling a portable fuel container.
- For your safety, we strongly recommend
that you do not travel with a portable
fuel container in your vehicle. The con­
tainer, full or empty may leak and could
cause a fire, especially in a crash.
- If, under exceptional circumstances, you
must transport a portable fuel container,
please observe the following:
- Never fill a portable fuel container
while it is anywhere in or on the vehicle
(for example, in the luggage compart­
ment, or on the trunk). Static electrici­
ty can build up while filling and can ig-
nite fuel vapors causing a fire. .,.
'------------=---------

.. Loosen the loop C? fig. 193 from the retaine r
and then pull on t he loop carefully
~CD-
.. Press on the left s ide of the fuel filler door
to open C?page 223, fig. 190.
(D Note
Only pull on the loop until you feel resist­
ance. You will not hear it release . Other­
w ise you could damage the emergency re­
lease mechanism .
Selective catalytic
reduction
General information
Applies to vehicles: with d iesel e ng in e
On vehicles w ith select ive catalytic reduction,
an urea solut ion (Ad Blue) is injected into the
exhaust system befo re a nitrogen oxide cata ­
lytic converter to reduce nitrogen emiss ions .
The AdBlue is stored in a separate tank in the
ve hicle. The Ad Blue usage accounts for ap­
prox imately 0 .5% to 1.2% of the diesel fuel
that is used .
You must refill the Ad Blue or have it refilled by your authorized Audi dealer or qualified
workshop as soon as the Ad Blue refill mes ­
sage appears in the instrument cluster
C? poge 226.
,& WARNING
Failure to hee d Ad Blue refi ll information in
t he ins trument cl uste r can preven t the ve­
hicle from being s tarted and d rive n. If the
vehicle cannot be driven and an eme rgency
ar ises, persona l injury can occur.
- Always have the Ad Blue tank refilled well
before the tank runs dry .
@ Tips
-The ins trument clus ter display indi cates
the distance remaining that ca n be driv­
en
C? page 225 . If the Ad Blue tank is
complete ly empty, the engi ne will not
start again after the ignition is switched
off.
Fu el suppl y and filli ng your fuel t ank 225
- Ad Blue is req uired by law to ope rate this
vehicle .
Indicator in the instrument cluster
display
Applies to vehicles: wit h diese l engine
The display indicates if the Ad Blue level is low
or if it was filled incorrectly.
Fi g. 194 In strume nt cl uste r: indicator in the d isp lay
AdBlue level low
You w ill be informed if t he Ad B lue in the tank
drops below a certa in level.
Please refill Ad Blue. Range 1500 miles
( 2400 km )
This indicator appears when there is on ly
enough AdBl ue left to drive the distance indi­
cated in the driver information system. Please
add AdBlue.
AdBlue /; Refill AdBlue! Cannot start en­
gine in 600 miles (1000 km) ! See owner 's
manu al
This indicator appears when there is only
enough Ad Bl ue left to d rive the distance indi­
cated in the driver information system. Please
add AdBl ue. Otherwise the engine will not
start again if you stop it once the distance in­
dicated has been driven.
Refill AdBlue! No rest art! See
owner's m anual
T his message appears w hen the Ad Blue tank
is empty. P lease ad d Ad Blue. Otherwise you
will not be able to start the eng ine again once
you stop it. ..,.

226 Fuel supply and filling your fuel tank
When the minimum AdBlue leve l has been
reached, you must add Ad Blue ¢
page 226.
¢-fi Filling incorrectly
If the Ad Blue tank was filled with a different
fluid than Ad Blue and the system detects that
it is incorrect, a message w ill appear.
Ad Blue../ AdBlue: Sy stem fault No restart
in 600 miles (1000 km)! See owner's man­
ual
This message appears when it is only poss ible
to drive the distance indicated in the dr iver in­
formation system. Drive to the nearest quali­
fied workshop to have the malfunction re­
pa ired. Otherwise the engine will not start
again if you stop it once the distance ind icated
has been driven.
Ad Blue: System fault No restart!
See owner's manual
This message appears if the system detects it
was filled incorrect ly. Drive immed iately to
the nearest qualified workshop to have the
malfunction repaired. Otherwise you will not
be ab le to start the engine again once you
stop it.
Filling AdBlue
Applies to vehicles: with diesel engine
A special refill bottle must be used to fill the
AdBlue .
Fig. 195 Rig ht rear vehicle s ide: removing the Ad B lue
filler cap
Fig. 196 AdBl ue fille r tube: inse rti ng the refill bottle
The Ad Blue filler tube is located near the d ie ­
sel fi ller tube . Always add 1 ga llon (3.8 liters)
of Ad Blue (two bott les) . Th is is the minimum
amount required to ensure the system detects
the refill ing and to start the engine . You can
add a maximum of approxima tely 4 gallons
(16 liters).
Opening the filler tube and adding
AdBlue
Requirement: The request to add Ad Blue must
appear in the instrument cluster display.
" Switch the ignition off.
"O pen the tank cover
r::!> page 223.
"Tur n the Ad B lue filler cap counterclockwise
to remove it
r::!> fig. 195.
"Remove the cap from the refill bottle .
.. Position the refill bottle on the filler tube
and turn the bottle clockwise until it stops
turning (Dr:!>fig .196 .
" Press lightly against the bottom of the bot­
tle @to empty it. Continue pressing the
bottom of the bottle until it is empty or un­
til flu id stops flowing into the tank.
" Turn the bottle to the left w ithout pressing
on the bottom.
Closing the filler tube
" Turn the AdB lue fi ller cap clockw ise on the
fi ller tube until you hear it engage.
" Close the tank cover.
After filling
The vehicle must be driven. The system may
take up to two minutes to detect that the
AdBlue has been f illed. .,.

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~ If there was no Ad Blue left in the tank and a
range of
O mi (0 km ) was displayed in the
instrument cluster, switch the ignition on
for about 15 seconds before starting the en­
gine.
_& WARNING
Ad Blue can irr itate the skin, eyes and res­
piratory system . If there is contact with
the fluid, flus h immed iately with plenty of
wate r. Consult a physician if necessary.
(D Not e
-Only use Ad Blue that conforms to the
standard ISO 22241-1. Do not mix any
additives with the Ad Blue and do not di­ l ute it with water .
- Do not add Ad B lue to the diesel tank or
add diesel fuel to the Ad Blue tank. M ix­
i ng can lead to damage to the engine
and the Ad Blue tank system . The Limited
New Vehicle Warranty does not cover
such damage.
- Ad Blue attacks surfaces such as painted
vehicle components, plastic and carpet.
Remove the fluid as quick ly as possib le
with a damp cloth and plenty of cold wa­
ter. If the Ad Blue has already crystal­
lized, use warm water and a sponge.
AdBlue residue that is not removed w ill
crystall ize and can damage the affected
surface.
- Do not store the refill bottle in the vehi­ cle. If it leaks, the escap ing Ad B lue could
damage the vehicle inter ior.
- Do not allow Ad Blue to come into con­
tact with clothing. If there is contact
with the flu id, flush immediately with
plenty of water.
(D Tips
- You can obtain refill bott les from any au­
thorized Audi dealer or other qua lified
workshop.
- Follow the AdBl ue manufacturer's in­
str uctions for usage and sto rage.
Fu el su ppl y and fi lling yo ur fu el t an k 22 7
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228 Checking and filling
Checking and filling Engine hood
Releasing the engine hood
The engine hood is released from inside the
vehicle .
Fig. 197 Driver foo twell: release lever
Fig. 198 Rocker switch un der the hood
Make sure the wiper arms are not raised up
from the windshield. Otherwise the paint
could be damaged.
.,. Pull the lever under the instrument panel in
the direction of the arrow
¢ fig. 197.
.,. Raise the hood slightly¢,&. .
... Press the rocker switch under the hood up­
ward ~
fig. 198. This releases the catch.
• Open the hood.
&_ WARNING
Hot engine coolant can burn you.
- To reduce the risk of being burned, never
open the hood if you see or hear steam
or coolant escaping from the engine compartment . Wait until no steam or
coolant can be seen or heard before care­
fully opening the hood .
'Working in the engine compartment
Be especially careful whenever you work in
the engine compartment.
Whenever you must perform any work in the
engine compartment, for example checking
and filling different fluids, there is a risk of injury, burns and accidents. To prevent per­
sonal injury always observe the following
WARNINGS. The engine compartment of any
vehicle is a hazardous area
¢ ,&. .
A WARNING
To help avoid injury, before you check any­
thing under the hood:
- Turn off the engine.
- Switch off the ignition .
- Apply the parking brake.
- Move selector lever to "P" (Park) .
- Always let the engine cool down. Hot
components will burn skin on contact.
- To reduce the risk of being burned, never
open the hood if you see or hear steam
or coolant escaping from the engine
compartment. Wait until no steam or
coolant can be seen or heard before care­
fully opening the hood.
- Keep children away from the engine com­
partment.
- Never spill fluids on hot engine compo­
nents . They can cause a fire .
- Never touch the radiator fan. The auxili­
ary electric fan is temperature controlled
and can switch on suddenly .
- Never open the coolant reservoir cap
when the engine is still warm . The cool­
ant system is pressurized and hot cool­
ant could spray out.
- Protect your face, hands and arm from
steam or hot engine coolant by placing a
thick rag over the cap when you open the
coolant reservoir.
- Do not
remove the engine cover under
any circumstances. This increases the
risk of burns.
- If work on the fuel system or the electri­
cal system is necessary:

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-Always disconnect the battery.
- Never smoke or work near heaters or open flames. Fluids in the engine com­
partment could start a fire.
- Keep an approved fire extinguisher im­
mediately available.
- To avoid electrical shock and personal in­
jury while the engine is running or being
started, never touch :
- Ignition cables
- Other components of the high voltage
electronic ignition system.
- If you must perform a check or repair
with the engine running:
- First, fully apply the parking brake,
move selector lever to "P" (Park).
- Always use extreme caution to prevent
clothing, jewelry, or long hair from get­
ting caught in the radiator fan, V-belts
or other moving parts, or from contact­ ing hot parts. Tie back hair before
starting, and do not wear clothing that
will hang or droop into the engine.
- Minimize exposure to emission and
chemical ha zards c:::> & .
A WARNING
California Proposition 65 Warning:
- Engine exhaust, some of its constituents,
and certain vehicle components contain
or emit chemicals known to the State of
California to cause cancer and birth de­
fects and reproductive harm. In addition ,
certain fluids contained in vehicles and
certain products of component wear con­
tain or emit chemicals known to the
State of California to cause cancer and
birth defects or other reproductive harm .
Checking and filling 229
-Battery posts, terminals and related ac­
cessories contain lead and lead com­
pounds, chemicals known to the State of
California to cause cancer and reproduc­
tive harms. Wash hands after handling.
(D Note
When adding fluids, always make sure that
they are poured into the proper container
or filler opening, otherwise serious dam­
age to vehicle systems will occur.
(® For the sake of the environment
To detect leaks in time, inspect the vehicle
floor pan from underneath regularly . If
you see spots from oil or other vehicle flu­ ids, have your vehicle inspected by an au­
thorized Audi dealer.
Closing the engine hood
.,. Pull the hood down until the pressure from
the struts is reduced.
"'Let the hood
drop down and latch in place.
Do not try to push it shut; it may fail to en­
gage
c:::> ,A .
A WARNING
-
A hood that is not completely latched
could fly up and block your view while driv ­
ing .
- When you close the engine hood, check it
to make sure the safety catch has proper­ ly engaged. The hood should be flush
with the surrounding vehicle body parts.
- If you notice while driving that the hood
is not secured properly , stop at once and
close it. •
•