check engine AUDI S8 2015 User Guide

88 On the road
switched off. More force is required to
stop and to steer the vehicle.
- To reduce the risk of injuries, make sure
that the Start-Stop-System is turned off
when working in the engine compart­
me nt¢
page 89.
(D Note
Always switch off the Start-Stop -System
when driving through water ¢
page 89.
Starting/stopping the engine
Applies to vehicles: with Start-Stop-System
Fig . 91 In strument duster : eng ine switc hed off (stop
phase)
~ Slow the vehicle to a stop using the brake
and keep pressing the brake pedal. The en­
gine w ill switch off. The
11] indicator light
appears in the information line in the instru­
ment cluster display.
~ When you take your foot off the brake ped­
al, the engine restarts . The ind icator light
turns off.
Additional information
The engine w ill switch off in the P, D, N and S
positions as well as in manua l mode. In the P
position, the e ngine will also remain off if you
take your foot off the brake pedal. The engine
starts again when you select another se lector
lever position and take your foot off the brake
pedal.
If you select the R position during a Stop
phase, the engine will start again .
Shift from D to P quickly to prevent the engine
from starting unintentionally when shifting
through R. You
can determine for yourself if the engine
will stop or not by reducing or increasing the
amount of force you use to press the brake
pedal. For example, if you only lightly press
on the brake pedal in stop-and and-go traffic
or when turning, the engine will not switch off
when the vehicle is stationary. As soon as you
press the brake down harder, the engine wi ll
switch off.
General information
Applies to vehicles: with Start-Stop-System
The standard Start-Stop-mode can be cancel­
led for different system-related reasons.
Fig. 92 Instrument cluster: eng ine -Stop temporarily
unavailable
Engine will not switch off
Before each stop phase, the system checks if
certain conditions have been met. For exam­
ple, the eng ine will
not be switched off in the
following situations:
- The engine has not reached the minimum
requ ired temperature for Start-Stop-mode.
- The interior temperature selected by the A/C
system has not been reached.
- The outside temperature is extremely high/
low.
- The windshield is being defrosted
¢page 81.
-The parking system* is switched on.
- The battery charge level is too low.
- The steering wheel is sharply turned or
there is a steering movement.
- After engaging the reverse gear.
- On sharp incl ines.

rl N
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@ Tips
-ABS and AS R on ly wor k co rrectly when
a ll fo ur wheels are eq uipped w ith identi­
ca l tires . Different tire s izes can lead to a
r educt io n in eng ine power.
- You may hear noises when the sys tems
desc ribed are working.
Switching on and off
Intelligent technology 199
- If
the ind ica tor li ght &J or m] (US A
mode ls)/ ri] (Ca nada models) ap pears,
t h ere may be a malfunction
c::> page 19,
¢ page 18.
ESC turns on automatically when you start the engine.
Fig . 188 Center co nsole with ESC O FF bu tton
ESC levels
Sport mode on
The following si tua tions are exceptions whe re
it may be usefu l to switch o n sport mo de to
allow the w heels to spi n:
- Rockin g the vehicle to free it when i t is st uck
- Dr iv ing in deep s now o r on loose g ro un d
- Dr iving with snow chains
Sport mode off
Behavior
T he E SC and AS R sta bilization f unct io ns The fu ll sta biliz ati on f uncti on o f the ES C
are limited ¢,& .
Operation Press the [ru button .
Indicator • tur ns on.
lights
Driver mes· Stabilization control (ESC): Sport
sages Warning! Reduced stability
A WARNING
Yo u should o nly sw itch sport mo de on i f
your dr iv ing abili ties and road cond itions
permit.
- The stabilization function is limited
when sport mode is sw itched on. The
dr iv ing whee ls co uld spin and the vehicle
cou ld swe rve , especially on slick or slip ­
pery road surfaces .
(D Tips
Sport mode cannot be switched o n when
adapt ive cr uise c ontrol* is sw itched on.
-
and AS R is availab le again .
Press the
[ru button again .
II turns off .
Stabilization control (ESC): On
Braking
General information
What affects braking efficiency?
Operating conditions and driving habits
The bra ke s on today's au to m obiles a re s till
sub ject t o wear, depe nding la rgely o n ope rat ­
i ng con dit ions and d riving habits ¢
A. On
vehicles that are either driven most ly in stop­
and-go city traff ic or are driven hard , the
brake pads should be checked by your author­
ized Audi dealer more often than specif ied in
t h e
Warranty & Maintenance booklet . Failure .,._

200 Intellig ent technol ogy
to have your brake pads inspected can result
in reduced brake performance.
On steep slopes, yo u shou ld use the b rak ing
effect of the engine. Th is way, you prevent un­
necessary wear on the brake system. If you
must use your brakes, do not hold the brakes
down continuously. P ump the brakes at inter ­
vals.
Operating nois e
Noises may occur when braking depending on
the speed, braking force and outside condi­
tions such as temperature and humidity.
E ff ect of water and road salt
In certain situat ions, for example after driving
through water , in heavy ra in , after overn ight
condensation or after washing your car, the braking effect can be reduced by moisture or
ice on the brake rotors and brake pads. The
brakes must be dried first with a few careful
brake applications.
At higher speeds and with the windshield wip­
ers turned on, the brake pads press against
the brake rotors for a short amount of time.
This occurs at regular intervals without the
driver noticing and provides for bet ter brake
response time under wet condit ions .
The effectiveness of the brakes can be reduced
when the vehicle is dr iven on a salt-covered
road and the brakes are not used . Likew ise,
you clean off accumulated salt coating from
brake discs and pads with a few caut ious ap­
plications of the brake
c:::> .&, .
Cor ro sion
There may be a tendency for dirt to build up
on the brake pads and corrosion to form on
the discs if the car is not dr iven regularly or
only for short t rips with little use of the
b rakes .
If the brakes are not used frequently , or if cor­
rosion has formed on the discs, it is advisable
to clean off the pads and discs by braking
firm ly a few times from a mode rately high
speed
c:::> .&, .
Faults in the brake syste m
If you shou ld notice a sudden increase in
brake pedal trave l, then one of the two brake
circuits may have fai led
c:::> & .
Low bra ke fluid lev el
Malfunctions can occu r in the bra ke system if
the b rake fluid level is too low. The brake flu id
level is monitored electro nica lly.
Brake booster
The brake booster works with vacuum pres­
sure which is created only when the eng ine is
runn ing
c:::> .&, .
Brake lining we ar statu s
Brake lining wear may be checked by visual in­
spect ion of the condition of the brake pads
through the open ings in the wheel. If neces­
sary, the wheel may be removed for th is in­
spect ion
c:::> page 269, Changing a wheel .
_& WARNING
-You shou ld perform braking maneuvers
for the purpose of cleaning the brake
system only if road conditions permit .
Other road users must not be put at risk -
you may ca use an accident!
- Before descending a steep grade, reduce
speed and sh ift transmission into a lower
gear or lower dr iving range. Do not ride
the brakes or hold the pedal down too
long or too often . This could cause the
brakes to get hot and diminish braking
efficiency.
- Do not "ride the brakes" by rest ing your
foot on the pedal when you do not intend
to b rake . This may cause the brakes to
overheat, p remature wear and increased
s topping distance .
- Unde r ce rtain cl imatic and ope rat ing
conditions such as passing thro ugh wa­
ter, dr iving in heavy rain o r after washing
the vehicle, the effectiveness of the brakes can be reduced. In winter, ice can
accumu late on the brake pads, lin ings,
d iscs and drums. Carefully app ly brakes
for a test. Brakes will dry and ice

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A WARNING ,~
- Do not park your vehicle over flammable
materials such as grass or leaves because
the high temperature of the diesel par­
t icu late filter cou ld start a fire .
- Do not apply an underbody protectant in the exhaust system area or a fire could start .
Shutting down vehicle
If you would like your veh icle to remain inop ­
erat ive for a longer period of time, contact an
Aud i or other specia lized dealer. They can ad­
vise you on necessary precautions e.g . corro­
sion prevention, ma intenance and storage.
Pay attention to additiona l information con­
cerning the battery. Refer to~
page 240.
Avoid damaging the
vehicle
When you a re driving on poor roads, or over
curbs, steep ramps, etc., make certain that low-lying parts such as spoilers and exhaust
system parts do not bottom out and get dam­
aged.
This is especially true for vehicles with low­
slung chassis (sports chassis)* and fully load ­
ed vehicles.
Driving through water
on roads
Note the following to avoid vehicle damage
when driving through water, for example on
flooded roads :
- The water must not be any higher than the
bottom of the veh icle body.
- Do not drive faster than wa lking speed.
A WARNING
After driving through water, mud, slush,
etc., the brakes may be slow to take effect
because of wet brake rotors and pads. Dry
-
Drivin g and environment 207
the brakes first by braking carefully to re­
store the full braking effect.
(D Note
- Vehicle components such as the engine,
transmission, suspension or electrical
system can be severely damaged by driv­
ing through water.
- Always switch off the Start-Stop-System*
when driving through water
~ page 87.
(D Tips
-Check the depth of the water before driv­
ing through it .
- Do not stop the vehicle, drive in reverse
or switch the engine off when driving
through water.
- Keep in mind that oncoming vehicles may create waves that raise the water
level and make it too deep for your vehi­
cle to drive through safely .
- Avoid driving through salt water because
it can cause corrosion.
Operate your vehicle
economically and minimize pollution
General
Your personal style of driving will determine
t he economy of your vehicle , as well as ex­
haus t and noise levels.
Fuel economy, environmental impact, and
wear on your engine, brakes and tires largely
depend on three factors:
- your personal driving style
- operating conditions
- technical limitations
If you ant icipate what you need to do next and
drive economically, you can easily cut your
fuel consumpt ion by 10-15 percent . This sec­
tion w ill give you some tips on how you can
help the env ironment and your pocketbook. •
•

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Trailer load distribution Be sure the load in the trailer is held securely
in place to prevent it from shifting forward,
backward or sideways.
Never allow a passenger to ride in a trailer
¢ .&. in Driving instructions on page 212.
Engine cooling system
Towing a trailer makes the engine work hard ­
er . It is important that the cooling system's
performance is up to the additional load .
Make sure that the cooling system has enough
fluid.
Tire pressure
When towing a trailer, inflate the tires of your
vehicle to the cold tire pressure listed under
"Full load" on the label located on the driver's
side B-pillar (visible when the door is open).
Inflate trailer tires to trailer and tire manufac­
turers' specifications.
Lights
Check to make sure both vehicle and trailer
lights are working properly.
Safety chains Be sure trailer safety chains are properly con­
nected from the trailer to the hitch on the ve­
hicle . Leave enough slack in the chains to per­
mit turning corners . When you install safety
chains, make sure they will 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
be­
fore
hitching up the trailer and before adjust ­
ing the tongue weight. The vehicle must be in
auto or comfort driving mode and not raised
¢page 108, ~CD .
Make sure that the vehicle is lowered. In Info ­
tainment, select:
ICARI function button> low­
er control button .
Trailer towing 211
If you must drive under poor road conditions,
you can raise the vehicle
after coupling the
trailer or
after adjusting the tongue weight
¢ page 110.
@ Note
- Changes in temperature or load can af­
fect the height of the vehicle.
- Always select auto or comfort mode.
Otherwise, the tongue load specified for
your vehicle will no longer be applicable.
Driving instructions
Driving with a trailer always requires extra
core and consideration.
To obtain the best possible handling of vehicle
and trailer, please note the following:
.,. Do not tow a loaded trailer when your car it­
self is not loaded .
.,. Be especially careful when passing other
vehicles.
.,. Observe speed limits.
.,. Do not drive at the maximum permissible
speed .
.,. Always apply brakes early .
.,. Monitor the temperature gauge.
Weight distribution
Towing a loaded trailer with an empty car re­
sults in a highly unstable distribution of
weight. If this cannot be avoided, drive at very
low speeds only to avoid the risk of losing
steering control.
A "balanced" rig is easier to operate and con­
trol. This means that the tow vehicle should be loaded to the extent possible and permissi­
ble, while keeping the trailer as light as possi­
ble under the circumstances . Whenever possi­
ble , transfer some cargo to the luggage com­
partment of the tow vehicle while observing
tongue load requirements and vehicle loading
considerations .
Speed
The higher the speed, the more difficult it be­
comes for the driver to control the rig. Do not .,.
•
•

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-Blend must contain not more than 1S%
MTBE.
Seasonally adjusted gasoline
Many gasoline grades are blended to perform
espec ially we ll for winter or summer driving.
During seasonal change-over, we suggest that
you fill up at busy gas stat ions where the sea­
sonal adjustment is more likely to be made in
time .
(D Note
-Methanol fuels which do not meet these
requirements may cause corrosion and
damage to plastic and rubber compo­
nents in the fuel system.
- Do not use fue ls that fail to meet the
specified criter ia in this chapter.
- If you are unable to determine whether
or not a particular fue l blend meets the
specifications, ask your service station or
its fuel supp lier.
- Do not use fuel for which the contents
cannot be identified.
- Fuel system damage and performance
problems resulting from the use of fuels
different from those specified are not
the responsibility of Audi and are not
covered under the New Vehicle or the Emission Control System Warranties.
- If you experience a loss of fuel economy
or driveability and performance prob­ l ems due to the use of one of these fuel
blends, we recommend that you switch
to unblended fuel.
Gasoline additives
Appl ies to vehicles : wit h gasoli ne e ng in e
A majo r concern among many auto manufac­
ture rs is carbon deposit build-up caused by
the type of gasoline you use.
Although gasoline grades differ from one manufacturer to another , they have certain
things in common. All gasoline g rades contain
substances that can cause deposits to collect
on vital engine parts, such as fuel injectors
and intake valves. Although most gasoline
Fuel supply and filling your fuel tank 221
brands include additives to keep engine and
fuel systems clean, they are not equally effec­
tive .
Audi recommends using TOP TIER Detergent
Gasoline . For more information on TOP TIER
Detergent Gasoline, please go to the official
webs ite (www.toptiergas.com).
After an extended per iod of using inadeq uate
fuels, carbon deposit build-ups can rob your
engine of peak performance.
(D Note
Damage or malf unct ion due to poor fuel
quality is not covered by the Audi New Ve­
hicle Limited Warranty.
Diesel fuel
Applies to veh icles : w ith diese l en gine
Always use ULSD (Ultra Low Sulfur Diesel)
No. 2. The ULSD No. 2 meets the ASTM D97S.
Diesel fuel with concentrations of biodiesel
highe r than S % such as Bll, B2O or BlOO are
strictly prohib ited .
Se rv ice stat ion fuel pumps are labeled with
the cor rect fuel informat ion for easy recogn i­
tion by the user. If the diesel fuel pump is not
labeled ask the station operator what fuel is
being dispensed before filling up your vehicle.
ULSD No. 2 may not be available outside the
USA and Canada. Be sure to check before trav­
eling to other countries .
Winter operation
ULSD No. 2 can become thicker in the winter .
Because of this, gas stations sell ULSD No. 2
with imp roved flow when cold during the win­
ter. Ask the gas stat ion attendant if the diesel
sold is winterized sufficient ly for the current
and the predicted temperatures.
If not winterized o r insuff icient ly w interized
ULSD No. 2 has already thickened to the ex­
tent that the engine will not start, warm the
vehicle up by leaving it in a heated garage.
Ill-
•
•

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. .,.
'------------=---------

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. •
•

230 Checking and filling
Engine compartment
Engine compartment overview
These are the most important items that you can check.
Fig. 199 Typical layo ut for co nta iners a nd eng ine o il filler cap
Fig. 200 Layo ut of th e rese rvo ir, engine o il filling o penin g and o il dipstick for the W 12 eng ine