2015 AUDI A4 check engine light

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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). .,.

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.
rl l/1 rl
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.

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>

196 Driving and en vironm ent
Reducing unnecessary idling
Even when your car is just idling it burns up
fuel .
.,. Shut the engine off when you are not dr iving
the vehicle.
.,. Do not warm up the vehicle by letting the
engine run at idle .
It makes sense to shut
off the engine in traffic
jams, when waiting for trains to pass at ra il­
road crossings, or at traff ic lights that have
l ong wa its on red . Turning the engine
off fo r
just 30-40 seconds saves more fue l than is
burned starting the eng ine again .
It takes a long time for the engine to warm up
fu lly when it is running at idle . Howeve r, wear
and nox ious em issions are especially high
when the engine is warming up. So you should
drive away as soon as you start the engine and
avoid running at high rpms while the engine is
still warming up .
(D Note
Do not leave engine idling unattended af­
ter starting . If warning lights shou ld come
on to indicate improper operation, they
wou ld go unheeded. Extended idling also
produces heat, which cou ld result in over­
heating or other damage to the vehicle or
other property .
Regular maintenance
A badly tuned engine unnecessarily wastes a
lot of fuel .
... Have your vehicle serviced at regular inter-
vals.
By having your vehicle regularly serviced by an
authorized Audi dealer he lps to ensure that it
runs properly and economically . The condition
of your vehicle not only affects its safety and
ab ility to hold its value, it also affects
fu el
con sumpt ion .
Check you r oil ea ch time you fill you r ta nk.
The amount o f oi l used is re lated to engine
load and speed.
It i s normal fo r the oil consump tion of a new
engine to reach its lowest value after a certa in
mileage has been d riven.
You must drive your veh icle about 3,000 m iles
(S,000 kilometers) before you can properly
assess oil consumpt ion.
This also app lies to fue l consumption and en­
gine output.
(D Note
- Have your veh icle ma inta ined properly
and in accordance with the service rec­
ommendations in your Wa rranty
& Main­
t enance boo klet . Lack of p roper ma inte­
nance as well as improper use of the ve­
hicle will impair the function of the
emission contro l system and cou ld lead
to damage.
- Do not alter or remove any component of
the Emission Control System unless ap­
proved by the manufacturer.
-Do not alter or remove any device, such
as heat sh ie lds, switches, ignition w ires,
valves, which are designed to protect
your vehicle's Emission Control System and other important vehicle compo­
nents.
Fewer short trips
Fuel consumption will always be relatively
high on short trips .
.,. Try to avoid dr iv ing short distances w ith a
cold engine .
T he engine and cata lytic converter have to
reach their opt imal
operat ing temperature to
reduce fuel consumpt ion and nox ious emis­
s ions effectively .
Just after starting, a co ld eng ine in a mid-s ize
car only achieves a fuel economy of 6-8 mi les
per gallon (30-40 l/100 km). After about a
half a mile, fuel economy cl imbs to 12 mpg
(20 l/100 km) . After about
2 .5 miles (4 km), ll>

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Trailer towing Driving with a trailer
General information
Your Audi was designed primarily for passen­
ger transportation .
If you plan to tow a tra iler, p lease remember
that the addit ional load will affect durab ility,
economy and performance .
T railer towing not on ly places more stress on
the vehicle, it also calls for more concentra­
tion from the driver.
F or this reason, a lways fo llow the operating
and driving instructions provided and use
common sense.
Technical requirements
Traile r hitch
Use a weight-carrying hitch conforming to the
gross trailer we ight. The hitch must be suita­
b le for your veh icle and trailer and must be
mounted secure ly on t he veh icle's chassis at a
technically sound location . Use only a t railer
h itch w ith a removab le ball moun t. A lways
check with the tr ailer hitch man ufac tur er to
make sure that you are using the correct
hitch.
Do not use a bumper hitch.
T he hitc h must be installed in such a way that
it does not inte rfe re with the impac t-absorb­
i ng b umper syst em. No modifica tions should
be made to the vehicle exhaus t and b rake sys­
tems . From t ime to time, check that a ll hitch
mo unt ing bolt s remain securely fas tened.
W hen you are not tow ing a trailer, remove the
trai le r hi tch ball moun t. T h is prevents the
hi tch from causing damage sho uld your ve hi­
cle be str uck from be hind
¢ &. .
Trailer brakes
If yo ur tra iler is equ ipped w it h a braking sys­
tem, check to be su re that it conforms to a ll
r eg ulat io ns .
Trailer towin g 199
The trailer hyd ra ulic bra ke system must not be
direct ly connected to the vehicle's hydraulic
brake system
¢ &. .
Safety chains
Alw ays use s afety chains between your ve hicle
and t he tra ile r.
Trailer lights
Tra ile r lights m ust meet all reg ulations . Be
su re to check w ith your authorized Audi dealer
fo r c orrec t w iri ng, sw itches, and relays.
Mirrors
If you a re unable to see the traffic behind you
u sing the regula r outside m irrors, then you
must insta ll ext ended mir ro rs. It is important
t h at you
always have clea r vis io n to the rear .
.8, WARNING
- If a trai ler has elec trica l br ake s plea se
no te th at t hese bra kes are not activat ed
by the fa ctory -fit ted control unit -risk of
accident!
- After removing the t railer hi tch, do no t
s to re it in yo ur vehicle . In case of sudden
brak ing, the hitch could fly fo rward and
in ju re you or yo ur passenge rs .
Operating instructions
Maximum traile r we ight
-
A trai ler fo r you r vehicle is limited to a typical
class 1 or class 2 tra iler.
Trailer load distribution
B e sure the lo ad in the tra iler is h eld secure ly
i n p lace to p reven t it from shifting fo rward,
backward or sideways.
Never allow a passenger to ride in a trailer
¢ &. in Driving instru ctions on page 200.
Engine cooling system
T owing a t railer ma kes t he engine wor k hard ­
er . It is impo rta nt that the cooling system's
perfo rman ce is up to the additional load.
Make sure tha t the coo ling sys tem h as enough
f lu id . .,..
•
•

200 Trailer towing
Tire pressure
When towing a trai le r, inflate the tir es 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
The headlight settings should be checked with
the trailer attached before dr iving off. Check
to make sure both vehicle and tra iler lights
are working properly.
Safety chains
Be sure trailer safe ty cha ins are properly con­
nected from the trailer to the hitch on the ve­
hicle. Leave eno ugh slack in the chains to per ­
mit turning corners. When you install safety
cha ins, make sure they w ill not drag on the
road when you are driving.
The chains shou ld cross under the trai ler
tongue to prevent it from dropping in case of
separation from the hitch.
Driving instructions
Driving with a trailer always requires extra
care and consideration.
To obtain the best possible handling of vehicle
and trai ler, p lease note the following:
.,. Do not tow a loaded trailer when your car it­
self is not loaded .
.,. Be especia lly 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 trai ler with an empty car re­
sults in a highly unstable distribution of
weight . If this cannot be avo ided, drive at very
low speeds only to avoid the risk of losing
steering control. A "ba
lanced" rig is easier to operate and con­
tro l. This means that the tow vehicle should
be loaded to the extent possible and permissi­
ble, while keep ing the trai ler as light as possi­
ble under the c ircumstances. Whenever poss i­
ble, transfer some cargo to the luggage com ­
partment of the tow veh icle while obse rving
tongue load requi rements and vehicle load ing
considerations.
Speed
The higher the speed, the more d iff icu lt it be­
comes for the driver to control the rig. Do not
drive at the maximum permissible speed. Re­
duce your speed even more if load, weather or
wind conditions are unfavorable -pa rticularly
whe n going downhill.
Reduce veh icle speed
immediately if the trail­
er shows the slightest s ign of sway ing.
Do not
try to stop the swaying by accelerating.
Observe speed limits . In some areas, speeds
for vehicles tow ing tra ilers are lower than for
regular vehicles .
Always apply brakes early. When driving
downh ill, shift into a lower gear to use the en ­
gine braking effect to slow the vehicle. Use of
the brakes alone can cause them to overheat
and fail.
Coolant temperature
The coolant temperature gauge c> page 10
must be observed carefully . If the needle
moves close to the upper end of the scale, re­
duce speed immediately and/or turn off the
air conditioner.
If the coolant temperature warning light •
i n the i nstrument cluster starts flashing, pull
off the road, stop and let the engine
idle for
abo ut two minutes to prevent heat build-up .
_& WARNING
Anyone not properly restrained in a mov­
ing vehicle is at a much greater risk in an
accident . Never let anyone ride in your car
who is not p roper ly wea ring the restraints
provided by Audi.
-

212 Checking and filling
Checking and filling
Engine hood
Releasing and opening the engine hood
The engine hood is released from inside the
vehicle .
Fig. 180 Driver's side footwe ll: e ngin e hood release
lever
... -- - -=-
Fig. 181 Release lever u nde r the engine hood
Before opening the engine hood, make sure
that the windshield wipers are flat against the
windshield. Otherwise, they could damage the
pa int on the hood.
... With the driver's door open, pull the lever
under the instrument panel in the direction
of the arrow
c> fig . 180.
... Raise the hood slightly c> .&,
... Press the rocker switch under the hood up­
ward
c> fig . 181 . This releases the catch.
... Open the hood.
A WARNING
Hot engine coo lant can burn you.
- T o 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 coo
lant can be seen or heard before care­
fully opening the hood.
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 WARNING
-
A hood that is not completely latched
could fly up and b lock 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 shou ld 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.
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
c> ,&..
A WARNING
-To help avoid injury, before you check any-
thing under the hood:
- Turn off the engine.
- Remove the ignition key.
- Apply the parking brake.
- Move selector lever of automatic trans-
mission to "P" (Park); put manual trans­
mission in Neutral.
- Always let the engine cool down. Hot
components will burn skin on contact .

214 Checking and filling
Engine compartment
Engine compartment
These are the most important items that you can check.
Fig. 182 Typical layout for containers and eng ine o il filler cap
(D Eng ine o il filler cap ("1::::r.) . . . . . 216
@ Jump start point(+) under a cov-
er .. .. .... ... ....... .... ..
224, 275
@ Bra ke fluid reservo ir (0)) . . . . . 221
@ Coolant expansion tank (-L) . . . 219
® Jump start point(-) with hex
head sc rew ..... .......... ..
224, 275
® W indshield/headlight* washer
. (" ') container o ....... . ... .. . 225
The pos ition o f the engine o il fi lling hole
¢ fig . 182 (item @) can differ depending on
the eng ine design.
A WARNING
Before yo u check anything in the engine
compartment, always read and heed all
WARNINGS
¢ .&. in Working in the engine
compartment on page 212.
-
Engine oil
· Engine oil specifications
The engine oil used must conform to exact
specifications.
The service interval disp lay in the instrument
cluster of your vehicle will inform you when it
is time for a n oil change . We recommend that
you have your oil changed by an authorized
Audi Se rv ice Adv isor.
If you have to top off the o il between o il
changes, use the Audi o il quality standard
specified in the tab le.
Audi oil quality standard
Gasoline
VW 502 00 or
engine vw 504 00