2015 AUDI A4 check engine

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Resetting the service interval display
Your authorized Audi dealer w ill rese t the cor­
responding service schedule after performing
the appropriate service on your vehicle. Yo u
also have the possibility to reset the oil
change schedule after having performed an
oil change according to Audi specifications.
Select
I CAR I function button > Service interval
display > Reset oil change interval
or !CARI
function button > Car systems* control but­
ton
> Servicing & checks > Reset oil change
interval.
0 Note
- Only reset the oil change d isplay when
you have completed an oil change.
-If you disconnect the battery terminals,
no calculat ions can be made for the serv­
ic e interval display during this tim e and
no service rem inder will appear. Remem­
ber that observing the proper service in­
terva ls is vitally important to extending
the life of your vehicle, particularly the
engine, and maintaining its va lue. Even if
the mileage dr iven is low, the max imum
period of one year from one serv ice to
the next must not be exceeded .
(D Tips
The informat ion in the Service Reminder
remains stored even when the vehicle bat­
tery is disconnected.
On-Board Diagnostic
system (OBD)
Malfunction Indicator Lamp (MIL)
The Malfunction Indicator Lamp (MIL) ¢..ift in
the instrument cluster is part of the On-Board
Diagnostic (OBD II) system.
The warning/indicator light illuminates when
the ignition is switched on and goes out after
the engine starts and the idle has stabilized .
This indicates that the MIL is work ing proper­
l y.
Driver information display 29
If the light does not go out after the engine
is started, or illuminates while you are driv­
ing , a malfunction may exist in the engine sys ­
tem.
If the light illuminates, the catalytic con­
verter could be damaged.
Continue d rivin g
with reduced power (avoid­
ing su sta ined high speeds and/or rapid accel ­
erations) and have the cond ition corrected.
Contact your authorized Audi dealer.
If the light illuminates, the electronic speed
li miter may also be malfunct ioning. For more
information
c;,page 30, Electronic speed
limiter.
An improperly closed fuel filler cap may also
cause the MIL light to illuminate
c:;, page 210.
On-Board Diagnostics
Fig. 18 Location of Data Link Connector (D LC)
On-Board Diagnostics monitors the compo­
nents of your emission contro l system . Each
monitored component in your engine system
has been assigned a code. In case of a mal­
function, the component will be identified
and the fault stored as a code in the control
module memo ry .
The MIL light may also illuminate if there is a
leak in the on-board fuel vapor recovery sys­
tem. If the light illumi nates afte r a refueling,
stop the vehicle and make sure the fuel filler
cap is properly closed
¢ page 210.
In order to make an accurate diagnosis, the
stored data can on ly be displayed using spe­
c ial diagnostic equipment (generic scan tool
for 080). .,.

32 Opening and clo sing
- If the power locking system should ma l­
function, you can lock the driver's door us ing the mechanical key
c:> page 3 7.
- If the power locking system should fail,
you can sti ll open the fue l tank flap in an
emergency
c:> page 211.
- You are we ll advised not to keep valua­
bles inside an unattended vehicle, visib le
or not. Even a properly locked vehicle
cannot provide the security of a safe.
- If the LED in the upper edge of the driv­
er's door panel comes on for abo ut 30
seconds after the vehicle is locked, there i s a ma lfunction in the power locki ng or
the anti-theft warning system. Have the
malfunction corrected by an author ized
A udi dealersh ip or qua lified repai r fac ili­
ty.
Key set
F ig . 19 Key set
@ Remote cont rol key with mechanical
key
You can centrally lock and unlock your vehicle
and start the engine with the master key with
remo te con trol. A mec hanical key is integ rat­
ed i n the master key
c:> page 33 .
@ Emergency key
The emergency key is not intended for con­
stant use.
It should on ly be used in an emer­
gen cy, fo r example, in place of the ign ition key
cc> page 84. Keep it in a s afe p lace and do
not ca rry it on your key ring .
Key replacement
If you lose a key, contact you r authorized Audi
dealer immed iate ly to have the
Lost key disa­
bled. Be sure to bring all your keys with you .
Number of keys
You can check the number of assigned keys to
yo ur vehicle
c:> page 11. This allows you to
make su re you have re ceived all of the keys
when you purchase a used vehicle.
Data in the master key
D uring d riving, s ervice and maintenance-rele­
vant data is continuously stored on your mas­
te r k ey. Your Aud i service adviser can read out
t hi s data and tell you abo ut the work yo ur
ve­
hicle needs . This applies also to vehicles with
convenience key*.
Personal comfort settings
If two people use one veh icle, it i s r ecom­
men ded that e ach person alw ays uses "t heir
own" maste r key. When the ignition is tu rne d
off or when the vehicle is locked, personal
convenience setti ngs for the following sys ­
tems are stored and assigned to the remote
master key.
- Climate contro l
- Powe r lock ing system
- Seat memory *
- Parking system*
- Adapt ive cru ise control*
- Side assist*
- Drive se lect*
T he s to red settings are au toma tically recalled
whe n you unlock the vehicle, when yo u open
t h e doors or w hen you t urn on t he ignitio n.
A WARNING
-Do not leave your vehicle unattended
wit h the key in the ignition lock. Entry by
unaut horized persons co uld endanger
you or result in theft or damage the vehi­
cle.
- Do not leave ch ildren unattended in the
veh icle, especially with access to vehicle

keys. Unguarded access to the keys pro­
vides children the opportunity to start
the engine and/or activate veh icle sys­
tems such as the power windows etc. Un­ supervised operation of any vehicle sys­
tem by ch ildren can result in serious in­
jury.
- Do not remove the key from the ignition
lock until the vehicle has come to a com­
plete stop. Otherw ise the steering col­
umn lock cou ld suddenly engage -caus­
ing the risk of an accident.
(D Tips
- The operation of the remote contro l key
can be temporarily disrupted by interfer­
ence from transmit ters in the vici nity of
the vehicle working in the same frequen ­
cy range (e .g . a ce ll phone, radio equip­
ment).
- Fo r security reasons, replacement keys
are on ly available from authorized A udi
dealer.
- For Declaration of Compliance to United
States FCC and Industry Canada regula­
tions¢
page 286.
Removing the mechanical key
Fi g. 20 Remote master key: removing the mechanical
key
.,. Press the release button@¢ fig. 20.
.,. Pull the mechan ical key @ out of the master
key.
~ Using the mechanical key, you can:
~ co -lock and unlock* the glove compartment on
rl :5: the passenger's side 9 page 67.
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Op enin g an d clos ing 33
- lock and unlock the lockable * rear bench
seat and pass-through*
r=;, page 71.
- activate the child safety locks on the rear
doors
r=;, page 41.
- lock and unlock the vehicle manua lly
r=;, page 3 7 if this should not be possible
with the master key.
- use the ignition key emergency release
r=:> page 34.
Check light and battery in the master
key
Fig . 21 Remote master key: removing the battery hold­
er
Che ck light in the ma ster ke y
The check light @ r=:> fig. 21 in the master key
provides information about different condi­
t ions .
.,. The check light turns on briefly once when a
button is pressed, and during an "inquiry"
by the convenience key system .
.,. If the check light does not come on, the bat­
tery is dead and has to be replaced. In addi­
tion, when the battery is dead the
!I indi­
cator light appears in the instrument cluster
disp lay as well as the message
Plea se
c hange k ey batt ery.
Master key battery replacement
"'Remove the mechan ical key r=;, page 33 .
"' Press the release button @ i=:> fig. 21 on the
battery ho lder and at the same time pull the
bat tery ho lder out o f the maste r key in the
direction of the arrow.
.,. Insta ll the new battery CR 2032 with the
" + " sign facing down .
.,. Push the battery holder carefu lly into the
master key.

82 On the road
On the road
Steering
Manually adjustable steering wheel
The steering wheel position is fully adjustable
up and down and forward and bock .
Fig. 96 Lever under the steering column
First, adjust the driver's seat correctly .
• Pull the lever
c> fig . 96 <=> &_ .
• Move the steer ing whee l to the desired posi­
t ion.
• Push the lever against the steering column
until it locks.
There must be at least 10 inches (25 cm) be­ tween your chest and the center of the steer­
ing wheel. If you cannot sit more than 10 in­
ches (25 cm) from the steering whee l, see if
adaptive equipment is available to help you
reach the pedals and increase the distance
from the steering wheel.
F or detai led information on how to adjust the
driver's seat, see
c> page 62.
A WARNING
Improper use of steeri ng wheel adjust­
ment and improper seating position can
cause serious personal injury.
- Adjust the steering whee l co lumn on ly
when the veh icle is not moving to pre­
vent loss of veh icle control.
- Adjust the driver's seat or steering wheel
so that there is a minimum of 10 inches
(25 cm) between your chest and the
steering wheel
¢ page 127, fig . 139. If
yo u cannot mainta in this min imum dis- tance, the airbag system cannot protect
you proper ly.
- If physical limitations prevent you from
sitting 10 inches (25 cm) or more from
the steering wheel, check with your au­
thorized Audi dealer to see if adaptive
equ ipment is ava ilable .
- If the steer ing wheel is aligned with your
face, the supplementa l driver's a irbag
cannot provide as much protection in an
accident . Always make sure that the
steer ing wheel is aligned with your
chest.
- Always hold the steering wheel w ith your
hands at the 9 o'clock and 3 o'clock posi­
tions to reduce the risk of persona l injury
if the driver's airbag dep loys .
- Never hold the stee ring wheel at the 12
o'clock position or with your hands inside
the steeri ng wheel rim or on the steering
wheel hub . Holding the steering wheel
the wrong way can cause serious injuries
to the hands, arms and head if the driv­
er's airbag deploys.
Ignition lock
Starting engine with the key
Applies to vehicles : w ith ign ition lock
The ignition is switched on and the engine
started with the ignition key .
Fig. 97 Ignit ion key
Sta rting th e engine
• Insert the key into the ignition lock .
• Manual transmission: Fully depress the
clutch pedal and move the shift lever to the
neutra l position .

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-Do not ride the brakes or press the brake
pedal too often or too long when driving
down a hill. Constant braking causes the
brakes to overheat and substantially re­
duces braking performance, increases
braking distance or causes complete fail­
ure of the brake system.
- To prevent the vehicle from rolling back
when stopping on inclines, always hold it
in place with the brake pedal or parking
brake.
- Never hold the vehicle on an incline with
a slipping clutch. The clutch opens auto­
matically when it becomes too hot from
the overload. An indicator lamp
mJ illu­
minates and a driver message appears
¢ page 99 when the clutch is overload­
ed .
- If the engine must remain running, never
have any driving position engaged when
checking under the hood. Make sure the
selector lever has securely engaged and
is locked in P with the parking brake set
¢ page 212. Otherwise, any increase in
engine speed may set the vehicle in mo­
tion, even with the parking brake ap­ plied .
0 Note
-S tronic- and tiptronic transmission:
When stopping on an incline, do not try
to hold the vehicle in place by pressing
the accelerator pedal while a driving gear
is selected. This can cause the transmis­
sion to overheat and can damage it. Acti­
vate the parking brake or press the brake
pedal to prevent the vehicle from rolling.
- S tronic- and tiptronic transmission: Al­
lowing the vehicle to roll when the en­
gine is stopped and the selector lever is in N will damage the transmission be­
cause it is not lubricated under those cir­
cumstances .
(D Tips
For safety reasons, the parking brake is re­
leased automatically only when the driv ­
er's safety belt is engaged in the buckle.
Transmission 97
Hill descent control
App lies to vehicles : wi th mult itronic/ S tro nic/tiptro nic
The hill descent control system assists the
driver when driving down declines .
Hill descent control is activated when these­
lector lever is in D/S and you press the brake
pedal. The transmission automatically selects
a gear that is suitable for the incline. Hill de­ scent control tries to maintain the speed ach­
ieved at the time of braking, within physical
and technical limitations. It may still be nec­
essary to adjust the speed with the brakes.
Hill descent control switches off once the de­
cline levels out or you press the accelerator
pedal.
On vehicles with the cruise control system*
¢ page 91 , hill descent control is also activat­
ed when the speed is set.
.&_ WARNING
-
Hill descent control cannot overcome
physical limitations, so it may not be able
to maintain a constant speed under all
conditions. Always be ready to apply the brakes .

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,...., ..,., ,....,
Audi adaptive cruise control and braking guard 109
-If you restrict or switch off the ESC, the
braking guard also switches itself off
¢page 187.
- Switch braking guard off when you are
loading the vehicle onto a vehicle carrier,
tra in, ship or other type of transporta­
tion. This can prevent undesired warn­ i ngs from the braking guard system.
Messages
App lies to vehicles: with Audi adaptive cruise co ntrol
Braking guard: Off
This driver message appears if the system is
turned off via the radio/MM!*. Otherwise, if
the system is turned off, the information ap­ pears every time shortly after the start of the
tr ip.
The driver message also appears if the system is not avai lab le due to a malfunction or if the
ESC is not switched on¢
page 187. If this is
the case, the system will not provide warnings
about a possible collision.
Braking guard: Activated
This driver message appears if sharp brake
press ure was applied due to an acute warning.
•••
Three wh ite dots appear if a setting cannot be
selected with the operat ing lever . For exam­
p le , this happens if you want to raise/lower
the speed even though there was no previous­
l y saved speed .
ACC: Deactivation
The driver message appears in vehicles with
manual transmission . If the clutch pedal was
pressed down for too long, the adaptive cruise
control turns off . A chime sounds as a rem ind­
er .
ACC: Sensor blocked
This message appears if the sensor view is ob ­
structed, for example by leaves, snow, heavy
spray or dirt. Clean the sensor¢
page 101,
fig. 113.
ACC: not available
The driver message appears if there is a mal­
function . The adaptive cruise contro l turns off .
A chime sounds as a reminder. Have the sys ­
tem checked by an authori zed Aud i dea ler or
authorized Aud i Service Fac ility.
ACC: unavailable
The driver message appears if, for example,
the brake temperat ure is too high. The adap­
tive cruise control is temporarily unavailable .
A chime sounds as a reminder.
Engine speed!
This driver message appears in vehicles with
manua l transmission if the driver had not up­
shifted or downs hifted in time while using
adaptive cruise control braking or accelerat­
ing, caus ing the vehicle to exceed or no t reach
the permitted limit speed. The adaptive cruise
control turns off. A chime sounds as a remind­
er .
Shift lever position!
Vehicles with an automat ic transmission: the
driver message appears if the selecto r lever is
shifted to the N position. Th e adaptive cruise
control is no t available while in this position.
Vehicles with manua l transm ission: the driver
message appears for vehicles with manual
transmission if there is no forward gear en­
gaged, meaning if the reverse gear or the 1st
gear is engaged or if the selector leve r is in
the neutral position . The adaptive cr uise con­
trol is not available while in th is position.
Stabilization control (ESC)
This message appears if the electronic stabili­
z ation control ( ESC) is taking action to stab i­
lize the vehicle. The adaptive cruise contro l
turns off. A chime sounds as a reminder .
Speed too low
This message appears if the current speed is
too low
to set or to maintain the desired
speed .
The speed be ing saved must be at least
20 mph (30 km/h). The cruise control is
turned off for speeds lower than 12 mph

188 Intelligent technology
allroad: ESC level s
Offroad mode on Offroad mode off
Behavio r
The ESC and ASR stabilization functions The fu ll stabilization f unction of the ESC
are limited ¢& .
Op eration Press the I.a OFFI button .
Indicato r II turns on.
light s
Driver me s- Stabilization control (ESC) : Offroad .
s age s Warning! R est rict ed stabilit y
It is only possib le to turn off the ASR up to 30
mph (SO km/h) for veh icles with front whee l
d rive. At about 45 mph ( 70 km/h) it a utomat i­
cally turns on aga in . It is possib le to turn off
the ASR at any speed for vehicles with all
wheel drive.
A WARNING
You should only switch sport mode/off­
road mode on o r switch ESC/ASR off if your
driving abilities and road cond itions per­
m it .
- The stabilization function is limited
when sport mode/offroad mode is switched on. The d riving wheels could
spin and the vehicle could swerve, espe­
ci ally on s lick o r sli ppery ro ad sur faces.
- all road: You should o nly sw itch off road
mode on when driving offroad.
- Sedan: Th ere is no vehicl e stabiliza tion
w hen ESC/AS R are switched off .
(D Tips
ESC/ASR cannot be sw itched off or sport
mode/offroad mode cannot be switched
on when cru ise control or adapt ive cru ise
contro l* is sw itched on .
Braking
What affec ts braking efficiency?
New brake pads
During the first 250 miles (400 km) , new
b rake pads do not possess their fu ll braking
effect, they have to be "broke n in" first ¢,& .
You can compensate fo r th is sligh tly redu ced and ASR is availab
le agai n.
Press t he
I.a OFF I button aga in.
II turns off.
Stabil izati on c ontrol (ESC ): On
braking powe r by p ushing harder on the bra ke
peda l. Avoi d heavy bra king lo ads dur ing the
break -in pe riod.
Operating conditions and driving habits
T he brakes o n today 's automobiles a re still
s u bject to wear, depe nding largely on ope rat­
i ng condi tions and driving habi ts¢ ,&. On
vehicles that are ei ther dr iven most ly in stop­
and -go city traffic or are dr iven hard, the
brake pads should be checked by your author­
ized Audi dea ler mo re often than specified in
the
Warranty & Maintenance booklet . Failure
to have your brake pads inspected can result in reduced brake performance .
On steep slopes, you sho uld use the braking
effect of the engine . This way, you prevent un ­
necessary wear on the brake system . If you
must use your brakes, do not hold the brakes
down cont inuous ly. Pump the brakes at inter­
vals.
Operating noi se
Noises may occur when braking depending on
the speed, brak ing force and outside cond i­
t ions such as temperature and humidity.
Effect of water and road salt
In certain situations, for examp le afte r driving
t hr ough water, in heavy rain, after overnight
condensation or after wash ing your car, the
braking effect can be reduced by moisture o r
ice on the brake rotors and brake pads. The
brakes must be dr ied first wi th a few ca reful
brake applicat io ns.
At higher speeds and with the windsh ield wip-
ers turned on, the brake pads press against
ll>

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the brake rotors for a short amount of time.
This occurs at regular intervals without the
driver noticing and provides for better brake response time under wet condit ions.
The effectiveness of the brakes can be reduced
when the vehicle is driven on a salt-covered road and the brakes are not used. Likewise,
you clean
off accumulated sa lt coating from
brake discs and pads with a few cautious ap­
plications of the brake
i:> ,& .
Co rrosion
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 trips with little use of the
brakes .
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 brak ing
firmly a few times from a moderately high
speed
i:> ,& .
Fa ult s in the brake system
If you should notice a sudden increase in
brake pedal travel, then one of the two brake
circu its may have failed
i:> ,& .
Low brak e flu id l eve l
Malfunctions can occur in the brake system if
the brake fluid level is too low. The brake fluid
leve l is monitored electronically .
Brake boo ste r
The brake boos ter increases the press ure that
you generate with the brake pedal. It works
only when the engine is running
. ¢ .&
Brake lining w ear statu s
Brake lining wea r may be checked by visual in­
spection of the condi tion of the brake pads
through the openings in the whee l. If neces ­
sary, the whee l may be removed for this in­
spection
c> page 263, Changing a wheel .
Intellig ent technolog y 189
A WARNING
-New brake pads don't have the best stop­
ping power and must be "b roken -in" dur­
ing the initial 100 to 150 miles (150 to
200 kilometers) of normal c ity dr iving .
You can compensate for this by pressing the brake pedal more firmly. This also
applies la ter when new pads are instal­
led.
- You should per form braking m aneuvers
for the purpose of cleaning the brake
system only if road conditions permit .
Other road users must not be p ut at risk -
you may ca use an accident!
- Before descend ing a steep grade, reduce
speed and sh ift transmission into a lower
gea r or lower dr iving range. Do not ride
the brakes or hold the pedal down too
long or too often . Th is 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 climatic and ope rat ing
conditions such as passing thro ugh wa ­
ter, dr iv ing 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, linings,
discs and drums. Carefully app ly brakes
for a test. Brakes w ill dry and ice coat­
ings w ill be cleaned
off after a few care­
fu l brake applicat ions .
- Driving for an extended period of time o n
salt-cove red roads without using your
brakes can a lso affect braking efficiency .
C lean
off accum ulated salt coa ting from
br ak e disc s and pad s wi th a few ca re ful
bra ke applications.
- If you damage the front spoiler, or if yo u
install a diffe rent spoiler, be s ure the ai r
f low to the front brakes is not obstruct­
ed . Otherw ise the bra ke system could •
•