2017 AUDI A6 check engine

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" N .... 0 0 <..:l ' Trailer towing Driving with a trailer
General information
Your Audi was designed primarily for passenger
transportation .
If you plan to tow a trailer, please remember that
the additional load will affect durability, econo­
my and performance.
Trailer towing not only places more stress on the
vehicle, it also calls for more concentration from
the driver.
For this reason, always follow the operating and
driving instructions provided and use common
sense.
(D Note
If you are going to tow a trailer, you must ac­
tivate the trai ler operation mode
c::> page 83, Operating instructions.
Technical requirements
Trailer hitch
Use a weight-carrying hitch conforming to the
gross trailer weight. The hitch must be suitable
for your vehicle and trailer and must be mounted
securely on the vehicle's chassis at a
technically
sound
location . Use only a trailer hitch with a re­
movable ball mount. Always check with the trail­
er hitch manufacturer to make sure that you are
using the correct hitch.
Do not use a bumper hitch.
The hitch must be installed in such a way that it
does not interfere with the impact -absorbing
bumper system . No modifications should be
made to the vehicle exhaust and brake systems .
From time to time, check that all hitch mounting
bolts remain securely fastened.
When you are not towing a trailer,
remove the
trailer hitch ball mount . This prevents the hitch
from causing damage shou ld your vehicle be
struck from behind
c::> .&, .
Tra iler towing
Trailer brakes
If your trailer is equipped with a braking system,
check to be sure that it conforms to all regu la­
tions.
T he trailer hydraulic brake system must not be
directly connected to the vehicle's hydraulic
brake system.
Safety chains
Always use safety chains between your vehicle
and the tra iler .
Trailer lights
Trailer lights must meet all regulations. Be sure
to check with your Audi dealer for correct wiring,
switches and relays.
Mirrors
If you are unable to see the traffic behind you us­
ing the regular outside mirrors, then you
must in­
stall extended mirrors . It is important that you
always have clear vision to the rear .
A WARNING
--
After removing the trailer hitch, do not store
it in your vehicle. In case of sudden braking,
the hitch could fly forward and injure you or
your passengers.
Operating instructions
Maximum trailer weight
A trailer for your vehicle is lim ited to a typical
class 1 or class 2 trailer.
Trailer load distribution
Be sure the load in the trailer is held securely in
place to prevent it from shifting forward, back­
ward or s ideways.
Never allow a passenger to ride in a trailer c::> .&.
in Driving instructions on page 85 .
Engine cooling system
Towing a trailer makes the engine work harder. It
is important that the cooling system's perform­
ance is up to the additional load. Make sure that
the cooling system has enough fluid . ..,.
83

Intelligent Technology
Braking
New brake p ads
New b rake pads do no t achieve the ir full b raking
effect during the firs t 250 mi (400 km) . They
m ust be "broken in" first .
Wear
Brake pad wear depends largely o n the way the
ve hicl e is driven and on operat ing cond it ions.
This is especi ally true if you are d riving frequently
in the c ity and on c urves or with a sporty driving
style.
Operating noise
Noises may occur when bra king depend ing on the
speed, b raking force and outs ide cond it ions s uch
as temperature and humidity.
Effect of water and road salt
In ce rtain s ituations, for example after driving
through water, in heavy ra in, afte r ove rnight con­
densat ion or after washing your car, the b raking
effect can be red uce d by mo isture or ice on the
b rake rotors and brake pads. The brakes must be
"dried" first with a few careful brake applica­
tions.
At highe r speeds and with t he windshie ld wipers
turned on, the brake pads press against the bra ke
rotors for a short amount of time . This action,
which is not felt by the driver, happens at regular
intervals and ens ures a better reaction time for
the brakes in wet weathe r.
The braking effect can also be reduced if you are
driving on sa lted roads and you do not apply t he
brakes for long periods of time. The layer of salt
on the brake rotors and pads must be worn off
first when the brakes are applied.
Corrosi on
Leaving the vehicle parked for long periods of
time, low mi leage and avo iding heavy brak ing
can contribute to corrosion on the brake rotors
and to d irty brake pads.
If you usually avoid heavy b raking or if there is
corros ion present, occasional heavy braking at
122
high speeds is recommended to clean the brake
rotors and pads¢.&. .
Brake system malfunction
if you not ice that the b rake peda l t ravel has sud­
denly increased, then a br ake circuit in the du al­
c irc uit b rake system may have malfunctioned.
Drive to an authorized A udi dealer or authorized
A udi Se rvice Facility immediate ly to have the
problem corrected. On the way there, drive w ith
reduced speed and keep in m ind t hat you will
need a longer distance to stop and you will need
to press the brake peda l harder .
lo w b rake fluid level
When the brake fluid level is low, malfunctions in
the brake system may occur. The brake fluid level
i s electronically monitored.
Brake booster
The brake boos ter amp lifies the pressure you ap ­
ply to the brake pedal. It only works when the en­
gine is running .
A WARNING
- Only app ly the brakes for the purpose o f
cleaning the brake system when road and
traffic conditions permit. You must not en­
danger other road users. This i ncreases the
r is k of an accident .
-
- Never let the ve hicle roll while the engine is
s topped because this i ncreases the ris k of an
accident .
- New brake pads do no t ach ieve the ir full
braking effect dur ing the first 250 m i
( 4 00 km). They m ust be "b roken in" fi rst.
However, you can compensa te fo r the
slightly reduced brak ing force by pressing
firm ly on the brake pedal. Avo id heavy brak ­
ing during the break-in period.
- Ce rtain weather and operating condi tions
such as d riving through water, dr iv ing in
heavy rain o r driv ing after washi ng your ve­
hicle can impai r the effectiveness of the
brakes. In the winter, ice may build up on
the brake pads, rotors and dr ums. Check

Check ing and F illing
Checking and Filling
Gasoline
Fuel supply
Applies to: vehicles with gaso line engine
Using the right fuel helps keep the environment
clean and prevents engine damage.
F u el r eco mmend ati on
The fuel recommended for your vehicle is unle ad­
e d pr em ium
grade gasoline . Audi recommends
using TOP TIER Detergent Gasoline with a mini­
mum octane rating of 91 AKI (95 RON). For more
information on TOP TIER Detergent Gasoline,
p lease go to the offic ial website
(www.toptiergas .com).
The recommended gasoline octane rating 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 il l slightly reduce engine pe r­
forma nce.
Us e un leade d gaso lin e onl y. Unleaded gasoline
is availab le throughout the USA , Canada, and in
most European countries . We recommend that
you do not ta ke your vehicle to areas or co unt ries
where un leaded gaso line may not be availab le.
For more information on refueling your vehicle,
see
¢page 192.
Octan e rating
Octane rating indicates a gasoline's ability to re­
sist engine damaging "knock" caused by prema­
ture ignit ion and detonation . Therefore, buy ing
the correct grade of gasoline is very important to
he lp prevent poss ible engine damage and a loss
of eng ine performance.
Gasoline most commonly used in the Un ited
States and Canada has the following octane rat­
i n gs that ca n usually be found on the filler pump:
- Premium Grade: 91 - 96 AKI
190
- Regu la r 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 use a ny fue l w ith o ctane ratings low­
er than 87 AKI or 91 RON othe rw ise expen­
sive engine damage wi ll occur .
- Do
not use leaded gasoline. The use of lead­
ed gasoline will severely damage your vehi­
cle's catalyt ic converter and its ability to
control exhaust emissions .
Blended gasoline
Applies to: vehicles with gasoline engine
Use of gaso lin e conta ining alcoho l or MTBE
(meth yl tertia ry butyl ether )
You may use unleaded gasoline blended with al­
cohol or MTB E (commonly referred to as oxygen ­
ates) if the blended m ixture meets the follow ing
criteria:
Blend of g asoline methanol (wood alcohol o r
m eth yl alcoho l)
-Anti -knock index must be 87 AKI or h igher.
- Blend must contain no more than 3% metha-
nol.
- Blend must contain more than 2% co -solvents.
Blend of ga soline and ethanol (grain alcohol or
ethyl alc ohol )
- Anti-knock index must be 87 AKI or h igher .
- Blend must not conta in more than 15% etha-
nol.
Blend of gas oline and M TBE
- Anti-knock index must be 87 AK I or h igher .
- Blend must contain not mo re than 1S% MTB E.
S easonall y 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 .,..

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" N .... 0 0 <..:l ' fill up at busy gas stations where the seasonal
adjustment is more likely to be made in time .
(D Note
-Methanol f uels which do not mee t these re­
quirements may ca use corrosion and dam­
age to plastic and rubber components in the
fuel system.
- Do not use fuels that fai l to meet the speci­
fied criteria in this chapter.
- If you are unable to determine whether or not a particular fuel blend meets the speci­
fications, ask your service station or its fuel
supplier.
- Do not use fuel for which the contents can­
not be identif ied.
- Fuel system damage and performance prob­
lems resulting from the use of fue ls differ­
ent from those specified are not the respon­
s ibility of Audi and are not covered under
the New Veh icle or the Emiss ion Control
System Wa rrant ies.
- If you experience a loss of fue l economy or
driveability and performance problems due
to the use of one of these fuel b lends, we
recommend that you switch to unblended
fuel.
Gasoline additives
A ma jo r concern among many auto manufactur ­
e rs is carbon deposit build-up caused by the type
of gasoline you use.
A lthough gasoline grades d iffer from one manu ­
facturer to ano ther, they have certain things in
common . All gasoline grades contain substances
that can cause deposits to collect on v ita l eng ine
parts, such as fuel injectors and intake valves. Al­
though most gasoline brands include additives to
keep engine and fuel systems clean, they are not
equally effective.
Audi recommends using TOP TIER Detergent Gas­
oline. For more informat ion on TOP TIER Deter­
gent Gasoline, please go to the official website (www .toptiergas .com) .
Check ing and Filling
After an extended period of using inadeq uate
fuels, carbon deposit bui ld-ups can rob your en­
gine of peak performance.
(D Note
Damage or ma lf u nction due to poor fuel qual ­
ity is not covered by the A udi New Vehicle
Limited Warranty .
Diesel fuel
Applies to: vehicles with diesel engine
Always use ULSD (Ultra Low Sulfur Diesel) No. 2 .
The ULSD No . 2 meets the ASTM 0975.
Diesel fuel w it h concentrations of b iod iesel h igh­
er than 5 % such as Bl 1, B20 or BlOO are strict ly
prohibited .
Se rvice station fuel p umps are labe led with the
correct f uel info rmation for e asy recog nition by
the user.
If the d iesel fue l pump is not labeled
ask the station operator what fuel is being dis­
pensed before fil ling up your vehicle .
UL SD No . 2 m ay not be available ou tside the USA
and Canada . Be sure to check befo re t raveling to
other countries .
UL SD No . 2 can become thic ke r i n ve ry cold tem­
peratures, and th is can imp air the engine's s tart ­
ing and running. Depend ing on the sea son, gas
stations provide ULSD No . 2 that flows better in
cold temperatures so that you can continue oper ­
at ing your vehicle as usual.
@ Note
- Your vehicle's diese l engine was designed
soley for use with ULSD No . 2 . Therefore,
neve r use gasoline, heating oil, other fuels
or flow improvers. These contain substances
that will severely damage the fuel system
and the engine . Such damage will not be
cove red by your New Vehicle Limited War­
r a nty.
- If you put a ny amo unt of incorrect fuel in
the fuel tank, do not sta rt the eng ine under
any circumstances. Imme diately contact the
nea res t a uthor ized Audi dealer or author­
ized Aud i Serv ice Facility fo r ass istance .
191

Checking and Filling
These fuel s contain substances that can se ­
verely damage the fue l system and the en­
gine if the engine is started .
Refueling
Fuel filler neck
The fuel fille r neck is located on the r ight rear
side pane l beh ind the f uel fi ller flap.
If the power locking system should fail , you can
still open the flap manua lly - for deta iled instruc­
tions see~
page 194 .
You can find the fuel tank capac ity of your vehicle
i n
~ page 257 .
The label on the inside of the fuel filler flap tells
you the correc t fuel for your vehicle . For more in­
formation about fue l specifications , see
~ page 190 .
Your veh icle fuel t ank has an onboard refuelling
vapor recovery sys tem . This fea tu re he lps to pre­
vent fuel vapors from escaping from the tank and pollut ing the env ironment while you refuel your
ve hicle. In order to fill the tank prope rly while
p rotecting the environment, please fo llow this
re fueling proce dure caref ully.
8_ WARNING
Under no rmal o perating conditions, never car ­
ry additiona l fuel containers in yo ur car. Gas
canisters and ot her containers used to trans­
port fuel can be dangerous . Such containers,
full or empty, may leak and could cause a fire
in a collision . If yo u must t ransport fue l to
use for yo ur lawn mower, snow blower, etc.,
be
very careful and a lways observe loca l and
s tate laws regar ding t he use, transportation
a nd sto rage of s uch fue l conta iners. Make ce r­
t ain the con tainer mee ts in dust ry sta ndards
(A NSI/AS TM F8S 2 - 86) .
(D Note
Never d rive yo ur vehicle unt il t he fuel tan k is
c ompletely empty . T he irregu lar sup ply of
fue l can ca use m isfiri ng. Gasoline cou ld enter
t he exha ust system and damage the catalytic
converter.
192
Fueling procedure
Fi g. 17 4 R ig ht rea r side o f th e ve hicle: ope ning t he fuel
fi ll er door
Fig . 1 75 Fue l fill er doo r w it h at tac hed fu el cap
The fue l filler doo r is u nlocked or locked by the
central locking system .
Opening the fuel cap
" Press on the left side of the fue l filler door to
open
~ fig . 174.
"Unscrew the tank cap co unterclo ckwise .
" Place the cap from
above on the open f uel f iller
door
~ fig. 175 .
Closing the fuel cap
" Scr ew the tank cap on to the right on the filler
neck unt il it ca nnot turn any fart her .
" Then press on the left s ide of the t an k door un-
til it latches.
Once the pump no zzle switches off , t he fuel ta nk
i s "full ". Do not fill the tank mo re . O therwise the
expans io n sp ace in the tan k w ill be filled.
The co rrect fuel type for your vehicle can be
fo und o n a label located on the inside of the f uel
fille r door . Fo r addi tional informat io n on fuel,
see
~ page 190 .

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-Ad Blue is req uired by law to operate this ve ­
hicle .
Messages in the instrument cluster display
Appl ies to: ve hicles with selective ca talytic reduc tion
The display indicates if the Ad Blue level is low or
if there is a system malfunction.
AdBlue level low
You wi ll be informed if the Ad Blue in t he tank
dr ops below a certain leve l.
Please r efill Ad B lu e. Rang e x mi (km )
This message appears when there is only enough
Ad Blue left to drive the distance indicated in the
driver information system . Fill the AdBlue.
Ad Blue /9 Refill AdBlue! Cannot start engine
in x mi (x km )! See owner 's m anual
This message appea rs when there is only eno ugh
Ad Blue left to d rive the distance indicated in the
driver information system. Fill the AdBlue. Other­
wise the engine will not start again if you stop it
once the distance ind icated has been driven. You
can also check the remaining distance in the on­
board computer*.
Refill AdBlue! No restart! See o wn·
er 's manual
This message appears when the AdBlue tank is
empty. Fill the Ad B lue . Otherwise you will not be
ab le to start the engine again once you stop it.
The AdB lue m ust be refilled when the amount in
the tank has reached the minimum level
¢ page 195, Filling Ad Blue .
Incorrect filling/system malfunction
A message appears if the Ad Blue tank was filled
with a fluid other than AdBl ue and the sys tem
h as detec ted t hat the tank was f illed incorrect ly,
or if there is a system malfunction .
Ad Blue/ AdBlue : system fault . No restart in
x mi (x km ) See owner 's manu al
This message appears when it is only poss ible to
drive the d ista nce ind icated in the dr iver informa­
tion system. Drive to t he nearest autho rized Aud i
dealer or authorized Aud i Serv ice Facility to have
Checking and Filling
the mal func tion corrected. Otherw ise the engine
will not sta rt again if you stop it once the dis­
tance indicated has been driven .
Ad Blue: Syst em fault No re start!
See owne r's ma nual
T his message appears if the system has detected
that the tan k was fi lled incorrect ly or tha t there
is a ma lf u nction. Drive immed iate ly to the nea r­
est authorized A udi dealer or authorized Audi
Service Facility to have the malfunction correct ­
ed. Otherwise you will not be able to start the en ­
gine again once you stop it .
Filling AdBlue
Applies to : vehicles wi th selective cat alyt ic re du ctio n
Fi g. 17 8 Right rear side of the vehicle: removing t he AdBl ­
ue cap
The Ad Blue tank open ing is located near the d ie­
se l tank opening . Add at least 1.5 gallons (5 . 7
li te rs) of Ad Blue. This is the m inimum amo unt re­
quired to ensure the system detects the refilling
and to start the eng ine. You can add a max imum
of4.5 gallons ( 17 liters).
Requirement: the request to add Ad Blue mus t
appea r in the ins trument clus ter display.
.,. Switch the ignit ion off .
.,. Open the tank filler door ¢
page 192.
.,. Tur n the cap on the f iller ne ck coun ter-clock­
w ise using the wheel wre nch from the vehi cle
too l kit to remove it¢
fig . 178.
.,.. Fill the AdBlue using a bottle ¢ page 196 or a
canister
¢page 196. ..,.
195

Checking and Filling
& WARNING
AdBlue can irritate the skin, eyes and respira­tory system. If there is contact with the fluid,
flush immediately with plenty of water . Con­
sult a physician if necessary.
(D Note
- Only use Ad Blue that conforms to the
standard ISO 22241 -1. Do not mix any addi ­
tives with the Ad Blue and do not dilute it
with water.
- Do not add Ad Blue to the diesel tank or add diesel fuel to the Ad Blue tank. Do not start
the engine under any circumstances if the
wrong fuel is filled in the tank. There is a
risk of damaging the fuel tank system and
the engine. See an authorized Audi dealer or
authorized Audi Service Facility for assis­
tance.
- AdBlue attacks surfaces such as painted ve­
hicle components, plastic and carpet. Re­
move the fluid as quickly as possible with a
damp cloth and plenty of cold water. If the
Ad Blue has already crystallized, use warm
water and a sponge . AdBlue residue that is
not removed will crystallize and can damage
the affected surface.
- Do not store refill bottles or canisters per ­
manently in the vehicle. If the container
leaks, the escaping AdBlue could damage
the vehicle interior.
- Do not allow AdBlue to come into contact
with clothing. If there is contact with the
fluid , flush immediately with plenty of
wa­
ter.
(j) Tips
Follow the Ad Blue manufacturer 's instruc­
tions for use and storage.
Refilling AdBlue using a bottle
Applies to: vehicles with selective catalytic reduction
... Remove the cap from the refill bottle ¢.&. in
Filling AdBlue on page 196,
c::> (D in Filling
AdBlue on page 196.
196
... Position the bottle on the filler tube and turn
the bottle clockwise until it stops turning.
... Press lightly against the bottom of the bottle
to empty it . Continue pressing the bottom of
the bottle until it is empty or until fluid stops
flowing into the tank .
... Remove the bottle and seal the filler neck
c::> page 197, Completing AdBlue refill.
d) Note
Only use refill bottles that are approved for
your vehicle. Using other systems can cause AdBlue to leak.
(D Tips
- You can obtain refill bottles from an author­
ized Audi dealer or authorized Audi Service
Facility.
- A permitted refill bottle contains approxi­
mately 0.5 gallon (1.9 liters) of AdBlue.
Refilling AdBlue using a canister
Applies to: vehicles with selective catalytic reduction
®
+®
Fig. 179 Canister w ith attachable hose
... Remove the cover from the refill canister c::> .&.
in Filling AdBlue on page 196 , c::>(D in Filling
AdBlue on page 196 .
.,. Secure the end of the hose the canister @by turning the hose to the right.
.,. Remove the cap @from the other end of the
hose @.
... Position the end of the hose @on the filler
neck in the vehicle and turn the hose to the
right to tighten it .
... Lift the canister up and then tip it . Continue
holding the canister in a tipped position until it
1J,,

Check ing and F illing
- Do not drive until the fuel tank becomes
complete ly empty . The engine cou ld mis­
fire . Unburned fuel could also get into the
exhaust system and this cou ld cause the
catalytic converter to overheat.
- Do not sw itch off the ignition while the vehi­
cle is moving .
- Do not continue to operate your vehicle un­
der these cond itions, as otherwise fuel can
reach the catalytic converter . This could re­
su lt in overheating of the converter, requ ir­
i ng its replacement .
- To assure efficient operation of the Emis­
sion Control System :
- Have your ve hicle main tained pro perly and
in accordance with the service recommen ­
dations in your Wa rranty & Maintenance
book let.
- Lac k of proper maintenance as well as im ­
proper use of the vehicle will impair the
function of the emission cont rol system
and could lead to damage.
@ For the sake of the environment
Even when the Emission Control System is op­
erat ing properly, the exhaust gas can have a
sulfur-like exhaust gas smell under some op­
erat ing states . This depends on the su lfur
content of the fuel be ing used . Using a differ­
ent brand of fue l may he lp, or filling the tan k
w ith lead-free super grade gasoline.
Diesel particulate filter
A ppl ies to: ve hicles w ith diesel e ng in e
The diesel particulate fi lter filters nearly all of
the soot particles out of the ex haust. The f ilter
cleans i tse lf automatically under normal d riv ing
conditions. If the filte r ca nnot clean itse lf (for e x­
a mple , beca u se you are only driving sho rt distan­
ces), the fi lter becomes clo gged with soot and
the . symbo l for the diesel particulate fi lter il­
lum inates
c:> page 18.
A WARNING
- Do not park you r vehicle over flammable
materials such as grass or leaves because
198 -
the high temperature of the diesel particu­
late filte r could sta rt a fire .
- Do not apply an underbody protectant in the
exhaust system area or a fire could sta rt.
Engine compartment
· Working in the engine compartment
Special care is required if you are working in the
engine compartment
For work in the engine compartment, such as
checking and fill ing fluids , the re is a risk of in­
jury, scalding, accidents , and burns. For this
reason, follow all the warnings and general
safety precaut ions provided in the following in ·
formation . The engine compartment is a dan­
gerous area on the vehicle.
c:> .&, .
A WARNING
-Turn the engine off.
- S witch t he igni tion off.
- Set the park ing bra ke .
- Select the P s elector lever position.
-Let the eng ine cool down .
- Never open the hood when there is steam o r
coo lant escaping from the engine compart­
ment, because there is a risk that you could
be burned . Wait unt il no steam or coolant is
escaping .
- Keep children away from the eng ine com­
pa rtment .
- Never sp ill fluids on a hot eng ine. These flu­
ids (such as the freeze protection contained
in the coolant) ca n ca tch fire .
- Avoid short c ircuits in the electrical system .
- When working in the engine compa rtment,
remember that the radiator fan can switch
on even if the ignition is switched off, wh ich
increases the r is k of p ersona l injury.
- Never ope n the cap on the coolant expan­
sion tank when the engine is warm . The
coo ling system is under p ressure .
- To protect your face, hands, and arms from ho t steam or coolant, cover the cap with a
large cloth wh en opening .
~