2018 AUDI A8 check engine light

lL t:0 ....
"' " "' .... 0 0 :c ' cannot steer and brake as you usually
would, th is could lead to accidents and ser i­
ous injuries .
- To reduce the risk of injuries, make sure that
the Start/Stop system is turned off when
working in the engine compartment
i=> page80 .
(D Note
Always switch the Start/Stop system off when
driving through water
i::> page 80.
Starting/stopping the engine
App lies to: ve hicles with Start/Stop system
Fig. 92 Instrument cluste r: eng ine sw itched o ff (stop
p hase)
~ S low the vehicle to a stop us ing the brake and
keep pressing the brake pedal. The engine w il l
switch off. The
II indicator light appears in the
informa tion line in the instrument cluster dis­
play.
~ When you take your foot off the brake peda l,
the engine restarts. The indicator lig ht turns
off .
Additional information
The engine w ill switch off in the P, D, N and S po­
sitions as we ll as in manual mode . In the P posi ­
tion, the engine will also remain off if you take
your foot off the brake pedal. The engine starts
again when you se lect another selector lever po­
sition and take your foot off the brake pedal.
I f you select the R pos ition during a Stop phase ,
the engine will start again.
Shift from D to P quickly to p revent the engine
from star ting unintentionally when shifting
through R .
Drivi ng
You can de termine for yourse lf if the engine w ill
stop or not by reducing or increasing the amount
of force you use to press the brake pedal. For ex ­
amp le, if you only lightly press on the brake ped­
al in stop-and-go traffic or when turning, the en­
gine will not switch off when the vehicle is sta ­
t io nary . As soon as you press the brake down
harder, the engine w ill switch off .
(D Tips
-Press the brake pedal during a Stop phase
t o keep the vehicle from rolling .
- The ignit ion w ill turn off if you press the
! S T ART ENGINE STOPI button du ring a stop
phase.
General information
Applies to: vehicles w ith Start/Stop system
The standard Start/Stop mode can be canceled
for various system-related reasons.
Eng ine doe s not switch off
Before each stop phase, the system checks if cer ­
tain conditions have been met . If the
r,J indica­
tor light appears in the instrument cluster dis­
play, the eng ine will not be stopped, for example
in the following situations:
- The engine has not reached the minimum re­
quired temperature for Start/Stop mode.
- T he interior temperature selected by the cli-
mate control system has not been reached.
- The outside temperature is extremely high/low.
-The winds hie ld is being defrosted
~ page 71.
-The parking sys tem* is switched on .
- The vehicle battery cha rge level is too low .
- The steering wheel is tu rned at a sha rp angle or
is moving.
- After engaging the reve rse gear .
- On sharp incl ines.
Eng ine automatically restarts
T he standard Start/Stop mode wi ll be canceled
during a stop phase in the following situat ions .
The eng ine restarts without any action by the
driver .
79

Trailer towing
Trailer load distribution
Be sure the load in the trailer is held securely in
p la ce to prevent it from shifting forward, back­
ward or sideways .
Never allow a passenger to ride in a trailer~&.
in Driving instructions on page 91.
Engine cooling system
Towing a trailer makes the engine work harder . It
is important that the coo ling system's perform­
ance is up to t he additional load. Make sure that
the cooling system has eno ugh fluid .
Tire pressure
When tow ing a tra iler, inflate the tires of your
veh icle to the tire pressure listed under "Full
load " on the label
~ page 293. Inflate trailer
tires to trailer and tir e ma nufactu rers' specifica­
tions.
Lights
Check to make sure both vehicle and trailer lights
are working properly .
Safety chains
Be sure trailer safety chains are proper ly connect­
ed from the trailer to the hitch on the vehicle.
Leave enough slack in the chains to permit turn­
ing corners . When you install safety cha ins, make
sure they w ill not drag on the road when you are
driving.
The chains should cross under the trailer tongue
to prevent it from dropping in case of separation
from the hitch .
Adjusting the Audi drive select
Make sure the vehicle is on a level surface before
hitching up the trailer and before adjust ing the
tongue we ight. The vehicle must be in
auto or
comfort driving mode and not ra ised
~ page 111, ~0 .
Make sure that the vehicle is lowered. In Info­
tainment, select:
ICARI function butto n> Lower
control button.
90
If you must drive under poor road conditions, you
can raise the ve hicle
after coupling the trailer or
after adjust ing the tongue we ight ~ page 113.
@ Note
-Changes in temperature or load can aff ect
the height of the vehicle .
-Always select auto or comfort mode. Other­
wise, the tong ue load specified for your ve­
hicle will no longer be applicab le .
Driving instructions
Driving with a trailer always requires extra care
and consideration.
Weight distribution
Towing a loaded trailer with an empty car results
in a hig hly unstable distribution of we ight. If th is
cannot be avoided, drive at very low speeds only
to avoid t he risk of losing steering contro l.
A "balanced" rig is eas ier to operate and control.
This means that the tow vehicle s hould be loaded
to
the extent possible and permissib le, w hil e
keeping the trailer as light as possible under the
circumstances. Whenever possible, transfer
some cargo to the luggage compartment of the
tow veh icle while observing tongue load require­
ments and vehicle loading considerations.
Speed
The higher the speed, the more difficu lt it be ­
comes for the driver to control the rig . Do not
drive at the maximum permissible speed. Reduce
your speed even more if load, weather or wind cond it ions are unfavorable - particularly whe n
go ing down hill.
Reduce vehicle speed
immediately if the trailer
shows the slightest sign of sway ing.
Do not try
to stop the swaying by accelerating.
Observe speed limits. In some areas, speeds for
vehicles towing trailers are lower than for regular
vehicles.
A lways apply brakes early. When driving down­
hill, shift into a lower gear to use the engine
braking effect to slow the vehicle. Use of the
brakes alone can cause them to overheat and fail.
ll-

Intellig ent T echn olo gy
- New brake pads do not achieve their full
braking effect during the first 250 mi
(400 km). They must be "broken in" first.
However, you can compensate for the
sl ightly reduced brak ing force by pressing
firmly on the brake pedal. Avoid heavy brak­
i ng dur ing t he break- in per iod.
- Certa in weather and operat ing cond it ions
such as dr iv ing through water, driving in
heavy ra in or driving after washing your ve ­
hicle can impair the effectiveness of the
brakes . In the winter, ice may build up on
the brake pads, rotors and drums . Check
these components by braking carefu lly. Ap­
plying the brakes carefully severa l times
dr ies the brakes and removes ice bu ild-up.
- The effic iency of the brakes can also be im­
paired by driving for long stretches on roads
covered w ith salt w ithout using the brakes.
You can remove salt deposits from the brake rotors and pads by carefully applying
the b rakes severa l t imes .
- If the front spo iler is damaged or you install
another spoiler, make sure the front wheel
bra kes are vent ilated properly. Otherwise,
the brake system could ove rheat, w hich re ­
duces the ir effectiveness.
- Failure of a b rake circuit impa irs b raking
perfo rmance, which inc reases brak ing dis ­
tance . Avoid driving the vehicle and have it
towed it to the nearest authorized Audi
dealer or authorized Audi Service Facility .
- If the brake booster is not working, you will
have to press m uch harder on the brake
peda l to compensate for the lack of the
booster.
@ Note
- Never let the brakes " rub" by pressing the
pedal light ly when braking is not actually
necessary. This causes the brakes to over­
heat and increases braking distance and
causes wear.
- Before driving downhill a long distance on a
steep hill, decrease your speed and select a l ower gear. This makes use of the engine
braking effect and relieves the brakes. If
130
you need to brake add itiona lly, brake in in­
terva ls and not continuous ly .
(D Tips
- If the bra ke boos ter is not wor king, you
must press the brake peda l with much more
force than normal.
- If you retrof it your vehicle with a front spoi l­
er, wheel covers or simi lar items, make sure
that the air flow to the front wheels is not interrupted. Otherwise the brake system
can become too hot.
Electromechanical
steering, dynamic
steering
The electromechonicol steering supports the
driver's steering movements.
Power steering adapts electronically based on
the vehicle speed .
Indicator lights and messages
• Do not drive vehi cle: S tee rin g defect ive
If this indicator light turns on and stays on and
th is message appears, the power steering may
have failed .
Stop the vehicle in a safe location as soon as pos­
s ible. Do
not conti nue driving. See an authorized
Audi dealer or authorized Audi Service Fac il ity for
ass istance.
l;rfl St ee ring: System faul t You ca n cont inue
dr ivi ng
If the indicator light turns on and the message
appears, the steering wheel may be more diffi­
cu lt to move or more sensitive than usual. The
steering wheel may also be at an angle when driv ing stra ight .
Drive slowly to an authorized Audi dea ler or au­
thori zed Audi Serv ice Facility to have the mal­
funct io n corrected.
'-r-ij Dynamic stee ring: Init ializing
If the indicato r light is blinking and this message
appears, dynamic steering* is being initialized.
IJ>-

Checking and Filling
Checking and Filling
Gasoline
Fuel supply
Applies to: vehicles with gasoline engine
Using the right fuel helps keep the environment
clean and prevents engine damage .
Fuel recommendation
The fuel recommended for your vehicle is unlead­
ed premium
grade gasoline . Audi recommends
using TOP TIER Detergent Gasoline with a mini­
mum octane rating of91 AKI (95 RON). For more
information on TOP TIER Detergent Gasoline,
please go to the offic ial website
(www.toptiergas .com).
The recommended gasoline octane rat ing for
your engine can also be found on a label located
on the ins ide of the fuel filler flap. This rating
may be specified as AK I or RON .
Your veh icle may also be operated using unlead­
ed regular gasoline with a minimum octane rat ­
ing of 87 AKl/91 RON . However, using 87 AKI/91
RON octane fuel w ill slightly reduce engine per­
formance.
Use unleaded gasoline only. Unleaded gasoline
is available throughout the USA, Canada, and in
most European countries. We recommend that
you do not take your vehicle to areas or count ries
where un leaded gasoline may not be available.
For more information on refueling your vehicle,
see
~ page 269 .
Octane rating
Octane rating indicates a gasoline's ability to re­
sist engine damaging "knock" caused by prema­
ture ignit ion and detonation . T herefore, buy ing
the correct grade of gasoline is very important to
he lp prevent possible engine damage and a loss
of eng ine pe rformance.
Gasoline most commonly used in the United
States and Canada has the following octane rat­
ings that can usually be found on the filler pump:
- Premium Grade: 91 - 96 AKI
268
-Regular Grade: 87 -90 AK I
Explanation of the abbreviations :
AKI =
Anti Knock Index = (R +M)/2 = (RON +MON)/
2
RON = Research Octane Number
MON= Motor Octane Number.
@ Note
- Do not us e any fuel with octane ratings low­
er than 87 AKI or 91 RON otherwise expen­
sive engine damage will occur .
- Do
not us e leaded gasoline. The use of lead­
ed gasoline will severely damage your vehi ­
cle's catalytic converter and its ability to
contro l exhaust emissions .
Blended gasoline
Applies to: vehicles with gasoline engine
Use of gasoline containing alcohol or MTBE
(methyl tertiary butyl ether)
You may use unleaded gasoline blended with al­
cohol or MTBE (commonly referred to as oxygen ­
ates) if the blended mixture meets the follow ing
criteria :
Blend of gasoline methanol (wood alcohol or
methyl alcohol)
-Anti -knock index must be 87 AKI or higher.
- Blend must contain no more than 3% metha-
nol.
- Blend must contain more than 2% co-solvents.
Blend of gasoline and ethanol (grain alcohol or
ethyl alcohol)
- Anti-knock index must be 87 AKI or h igher .
- Blend must not conta in more than 15% etha-
nol.
Blend of gasoline and MTBE
-Anti -knock index must be 87 AK I or h igher.
- Blend must not contain more th an 15% MTBE.
Seasonally adjusted gasoline
Many gasoline grades are blended to perform es­
pecially well for winter or summer dr iv ing . Dur-
i ng seasonal change-over, we suggest that you
IJIJ,

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"' ......
"' .... 0 0 :c ' authorized Audi dealer or autho rized Audi
Service Facility.
- To reduce the risk of electric shock and in­
jury, never touch the following components
when the eng ine is running or is being start­
ed :
- I gnition cable
- Othe r components in the electronic h igh-
voltage ignition system
- If you must check o r perform work on the
engi ne while it is run ning:
- Set the parking bra ke and p lace the se lec­
tor lever in the P (pa rk) position first .
-Always p roceed with extreme ca utio n so
that clothing, jewelry or long ha ir do not
become caught in the radiator fan, fan
belt or other moving components or do
not come into contact with hot compo­
nents . Tie back long ha ir before beginning
work and do not wear cloth ing that can
hang down into the engine .
- L imit your exposure to exhaust a nd chemi ­
cals to as short a time as poss ible ¢
A.
A WARNING
California Proposi tion 6S Warn ing:
- Engine exhaust, some of its constituents,
and certain vehicle components contai n or
em it chem icals known to the State of C ali­
forn ia to ca use cancer and bi rth defects an d
re produc tive harm. In ad dition , ce rtain fl u­
ids contained in vehicl es and certa in prod ­
ucts of com ponent wear contain o r emit
chemica ls known to the State of California
to cause cancer and birth defects or other
reproduct ive harm.
- Battery posts, termina ls and re lated acces­
sories contain lead and lead compounds,
chemica ls known to the State of California
to cause ca ncer and reproduct ive harms .
Wash hands after handling .
(D Note
When fil ling fl uids, be sure not to mix the flu­
ids up . Otherwise severe ma lfunctions and en ­
gine damage w ill occur.
Chec king and Filling
@) For the sake of the environment
You should regularly check t he gro und under
your vehicle in order to detect leaks quick ly .
If
the re are visible spots from o il or other fluids,
b ring your veh icle to an authorized A udi deal­
er o r aut ho rized Aud i Serv ice Facility to be
checked .
Opening/closing the hood
The hood is released from inside the vehicle .
Fig. 256 Drive r footwell : re lea se leve r
Fig. 25 7 Rocker sw itc h unde r the hood
M ake s ure th e wipe r arms are no t rais e d up from
t h e windshie ld . Otherwise the pain t could be
damaged.
Opening the hood
.,. With the d rive r's doo r open, pull the lever be­
low t he instrume nt pane l in the direction of the
ar row ¢
fig. 256.
.,. Ra ise the hoo d slightly¢&_ .
.. Press the rocker switch under the hood upward
¢ fig . 257. T his re leases the catch.
.,. Open the hood . ..,.
273

Checking and Filling
Cl osing the ho od
~ Push the hood down until you override the
force of the strut .
~ Let the hood fall light ly into the latch. Do not
press it in.
c::> .&_ .
A 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.
Engine compartment overview
The most important check points .
-For safety reasons, the hood must always be
closed securely while driv ing. 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 lifted.
-If you notice that the hood is not latched
while you are driving, stop immed iate ly and
close
it, because d riving when the hood is
not latched increases the r is k of an accident.
Fig. 258 Typical locatio n of the rese rvoir and the engi ne o il fille r open ing
(D Washer fluid reservoir (Q) c::> page 281
@ J ump start point(-) with hex head screw
c::> page 280, c::> page 32 7
® Jump start point(+) under a cover
c::> page 280, c::> page 32 7
@ Engine oil label * w ith VW standard
c::> page 2 75
274
® Engine oil filler opening ( page 2 76
@ Brake fl uid reservo ir ((0)) c::> page 2 79
(J) Coolant reservoir (-L) c::> page 2 78
The engine oil filling opening (item @) may be
l ocated in a different area depending on the en-
gine version.
.,.

u. co .... N
" N .... 0 0 :c ' @ For the sake of the environment
-Oil should never enter the sewer system or
come into contact with the ground.
- Pay attention to legal requirements when
disposing of empty oi l containers .
Changing the engine oil
We recommend that hove your oil changed by on
authorized Audi dealer or a qualified service sta­
tion .
Before you check anyt hing in the engine compart ­
ment,
alw ays re ad and h eed all W ARNINGS ¢ &
in Working in the engine comportment on
page 272.
The engine oil must be changed according to the
intervals specified in your Warranty
& Mainte­
nance booklet . This is very important because the
lubricating properties of oil diminish gradually
during normal vehicle use.
Under some circumstances the engine oi l should
be changed more frequently. Change oil more of­
ten if you drive mostly short distances, operate
the vehicle in dusty areas or under predominantly
stop-and-go traffic condit ions, or have your vehi­
cle where temperatures remain below freezing
for extended periods .
Detergent additives in the oil will make fresh oil
look dark after the engine has been running for a
short t ime . Th is is normal and is not a reason to
change the oil more often than recommended .
Because of the problem of proper disposal, along
with the special tools and necessary expertise re­
qu ired, we strongly recommend that you have
your oil changed by an authorized
A ud i d ea ler or
a qualified se rvice station .
If you choo se to chang e your o il y ou rse lf, please
note the following important information:
A WARNING
T o reduce the r isk of personal injury if you
must change the engine oil in your ve hicle
yourse lf:
- Wear eye protection .
-
Check ing and F illing
- To reduce the risk of burns from hot engine
oil, let the engine cool down to the touch.
- When removing the oil drain p lug with your
fingers, stay as far away as possible. Always keep your forearm parallel to the ground to
help prevent hot oil from running down your
arm.
- Drain the oil into a container designed for
this purpose, one large enough to hold at least the total amount of oil in your engine.
- Engine oil is poisonous. Keep it well out of
the reach of children .
- Continuous contact with used engine o il is
harmful to your skin. Always protect your
skin by wash ing oil off thoroughly with soap
and wate r.
@ Note
Never mix oil additives with your engine oil.
These add itives can damage your engine and
adversely affect your Audi L imited New Vehi­
cle War ranty .
@ For the sake of the environment
-Before chang ing your o il, first make sure
you know where you can properly d ispose of
the used oil.
- Always dispose of used engine o il properly .
Do not dump it on garden so il, wooded
areas, i nto open streams o r down sewage
dra ins.
- Recycle used eng ine o il by tak ing it to a used
eng ine oi l collection fac ility in yo ur area, or
c ontact a se rvice station.
Cooling system
Coolant
The eng ine cooling system is filled w ith a mixture
of purified water and coolant additive at the fac­
tory. This coolant must not be not changed .
The coo lant level is mon itored through
the . in­
dicator
light¢ page 20. However, we do recom­
mend occasionally checking the coolant level
manually .
.,.
277

Checking and Filling
If you must add coolant, use a mixture of water
and coolant additive . Mixing the coolant additive
with distilled water is recommended.
Coolant additive
The coolant additive is made of anti-freezing and
corros ion protection agents. Only use the follow ­
ing coo lant additives .
Coolant additive Specification
Gl2evo
TL 774 L
Gl2++ TL 774 G
Gl3
TL 774 J
These additives may be mixed wi th each othe r.
The amount of coo lant additive that needs to be
mixed with water depends on the climate where
the vehicle will be operated. If the coolant addi ­
tive percentage is too low, the coo lant can free ze
and damage the engine.
Coolant addi- Freeze protec-
tive tion
Warm regions min.
40%, min. -13 °F
max . 45% (-25 °()
C old regions min.
50%, max. -40 °F
max.
55% (-40 °C)
@ Note
-Before the start of winter, have an author­
ized Audi dealer or authorized Audi Service
Faci lity check if the coolant additive in your
vehicle matches the percentage appropriate
for the climate. This is especially important
when driving in colder climates .
-If the appropriate coolant additive is not
available in an emergency, do not add any
other addit ive for risk of damaging the en­
g ine . If this happens, only use water and re­
store the correct mixture ratio with the
specified coolant additive as soon as possi­ ble.
-Only refill with new coolant.
-Radiator sealant must not be mixed w ith
the coolant.
278
Adding coolant
Fig. 260 Eng in e compar tment : coolant exp ansion tank
cover
Observe the safety precautions ~.&, in Working
in the engine compartment on page 2
72.
Checking the engine coolant level
~ Park the vehicle on a level surface .
~ Switch the ignit io n off.
~ Read the coolant level on the coolant expansion
tank ~ page 2 74. The coolant leve l must be be­
tween the MIN and MAX markings when the en­
gine in co ld. When the engine is warm it can be
slightly above the MAX marking,
Adding coolant
Requirement: there must be a residual amount of
coolant in the expansion
tank ~(©) .
~ Let the engine cool down .
~ Place a cloth over the coolant expansion tank
cap and unscrew the cap counterclockwise
~.&. -
~ Add coo lant mixed in the correct ratio
~ page 277 up to the MAX marking.
~ Make sure that the f luid level remains stable.
Add more coolant if necessary .
~ Close the cap securely .
Coo lant loss usually indicates there is a leak . Im ­
mediate ly drive your vehicle to an authorized
Audi dealer or authorized Audi Service Fac ility
and have the cooling system inspected. If the
cooling system is not leaking, a loss can come
from the coolant bo iling t hrough overheat ing
and being pushed out of the cooling system .