2015 AUDI A3 check engine light

the overload. The ml indicator light
turns on and a message appears
Q page 111 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
Q page 210. Otherwise, any increase in
engine speed may set the vehicle in mo­
tion, even with the parking brake set.
(y Note
- 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 automatic
transmission to overheat and can dam­
age it. Set the parking brake or press the
brake pedal to prevent the vehicle from
rolling.
- Allowing the vehicle to roll when the en­
gine is stopped and th@ selector lever is
in the N position will damage the auto­
matic transmission because it is not lu­
bricated under those circumstances .
- The transmission can overheat and be
damaged under certain driving and traf­
fic conditions such as frequent starts,
creeping for a long time , or stop-and-go
traffic. When the
ml or . indicator
light turns on, stop the vehicle at the
next opportunity and let the transmis­
sion cool
r::!> page 111.
-Allowing the vehicle to roll when the en­
gine is stopped will damage the S tronic
transmission because it is not lubricated
<=> page 261, Emergency towing with
commercial tow truck .
For safety reasons, the parking brake re­
leases automatically only when the driver's
door is closed and driver's safety belt is
fastened.
Automatic transmission 109
Hill descent control
App lies to vehicles : wi th S tronic tra nsmi ssio n
Hill descent control assists the driver when
driving down inclines .
Hill descent control is activated when these­
lector lever is in the D or S position and you
press the brake pedal. The transmission auto ­
matically selects a gear that is suitable for the
incline. Hill descent control tries to maintain
the speed achieved at the time of braking,
within physical and technical limitations. If
may still be necessary to adjust the speed
with the brakes . Because hill descent control
cannot sh ift down farther than 3rd gear, it
may be necessary to shift into tiptronic mode
in very steep areas. In this case, shift into 1st
or 2nd gear in tiptronic mode to use the en­ gine's braking force to relieve the brakes .
Hill descent control switches off once the in­
cline levels out or you press the accelerator
pedal.
On vehicles with a cruise control system*
Q page 79, hill descent control is also activat­
ed when the speed is set.
A 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 .
•

196 Driving and the environment
than the posted speed limit and weather con­
ditions permit.
Reducing unnecessary idling
Even wh en your car is just idling it burns up
fuel.
,.. Shu t the engine off when you a re not dr iv ing
the vehi cle.
... Do not warm up the vehicle by letting the
engine run at idle.
It is efficien t to switch off the engine when
stopped at railroad crossings and long red
lights. Turning the engine
off for j ust 30-40
seconds saves mo re f uel than is burned by
start ing the engine again.
It takes a long time fo r the engine to wa rm up
fu lly when it is running at idle. However , wear
and noxious emissions are especially high
when the engine is warming up. So you should
drive away as soon as you start the engine and
avoid ru nning at h igh rpms while the engine is
still warming up.
{[) Note
Do not leave engine idling unattended af­
ter starting. If warning lights s hould come
on to indicate improper operation, they
wou ld go unheeded . E xtended idling also
produces heat, which cou ld resu lt in over­
heat ing or o ther da mage to the vehicle or
o ther prope rty.
Regular maintenance
A badly tuned engine unnecessarily wastes a
lot of fuel .
... Have your vehicle serv iced at regular inter-
vals.
H aving your vehicle regular ly serviced by an
author ized Audi dealer helps to ensure that it
runs properly and economically . T he condition
of yo ur vehicle not only affects its safety and
ab ility to hold its value, it also affec ts
fuel
con sumption. Check
your oil each t ime you fill your tank.
T he amou nt of oi l used is re lated to engine
lo ad a nd speed.
It is normal fo r the oil consumption of a new
engine to reach its lowest valu e after a c erta in
mileage has bee n driven.
You must drive your veh icle about 3,000 m iles
(5,000 kilometers) before you can properly
assess oil consumpt io n.
This also app lies to fue l consumption and en­
gine output .
(0 Note
- Have your veh icle ma inta ined properly
and in accordance with the service rec­
ommendations in your Wa rranty
& Ma in­
tenance boo klet . Lack of proper ma inte­
nance as well as improp er use of the ve­
hicle will impair the fu nction of the
em iss io n con trol system and cou ld lead
t o dam age.
- Do not alte r or remove any component of
t he Emis sio n Control Sys tem unless ap­
proved by the manufacturer .
- Do not alter or remove any device, such
as hea t sh ie lds, swi tches, ig nitio n w ires,
valves, which are designed to p rotec t
your vehicle's Emission Control System
and other impo rtant vehicle compo ­
nents.
' Fewer short trips
Fuel consumption will always be relatively
high on short trips.
... Try to avoid dr iv ing sho rt distances w it h a
cold engine .
T he eng ine and cat alytic conver ter h ave to
re ach their opt imal
operating t emperature to
reduce fuel consumpt io n and nox ious em is­
sions effectively.
Jus t aft er s tarti ng, a c old eng ine in a mid-s ize
ca r on ly achieves a fuel economy of 6-8 m iles
per gallon (30 -40 l/100 km) . After about a
half a mile , fu el economy climbs to 12 mpg .,..

198 Trailer towing
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 durability,
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, always fo llow the operating
and drivi ng in str uctions provided and use
common sense.
@ Note
If you are going to tow a trai le r, you must
activate the trailer operation mode
c:::> page 198 , Operating instructions.
Technical requirements
Traile r hitch
Use a weight-carrying hitch conforming to the
gross trailer weight. The hitch must be suita­
b le for your veh icle and trailer and must be
mo unted secure ly on the ve hicle's chassis at a
technically sound loca tion . Use only a trailer
hi tch with a removab le ball moun t. A lways
check with the tra ile r hitch manufac turer to
make sure that you are using t he cor rect
hitch.
Do not use a bumper hit ch .
The hitch must be installed in such a way that
i t does not interfe re with the impact-absorb­
ing bumper system. No modifications should
be made to the vehicle exhaust and brake sys ­
tems . From time to time, check th at a ll hitch
mo unt ing bo lts remain securely fastened.
When you are not towing a trailer, remove the
tra iler hitch ball moun t. T his prevents the
h itch from causing damage sho uld your veh i­
cle be str uck from be hind
c:::> A .
Trailer brake s
If your trailer is equipped wi th a b ra ki ng sys­
tem, c heck to be sure t hat i t conforms to all
regulations .
T he trailer hyd rauli c brake system mus t not be
direc tly connec ted to the vehicle's hydraulic
brake system .
Safety chains
Always use safety chains between your veh icle
and the tra ile r.
Trailer lights
Trai ler lights must meet all regulations. Be
sure to check w ith your Audi dealer for correct
wiring, switches and relays .
Mirrors
If you are unable to see the traffic behind you
us ing the regular o utside mirrors, then you
must install extended mirrors. It is important
that you
always have clear v is ion to the rear.
A WARNING
--
Afte r removi ng the trailer hitch, do not
stor e it in your vehicle . In case of sudden
b raking, t he hitch co uld fly forwa rd and i n­
j ur e you or your passengers.
Operating instructions
Maximum trailer weight
A tra ile r fo r your vehicle is limited to a typical
class 1 or class 2 tr ailer.
Trailer load distribution
Be sure the load in the tra ile r is held secure ly
i n place to p revent it from shift ing forward,
backward or sideways.
Ne ver allow a pa ssenger to ride in a trailer
c:::> A in Driving instructions on page 199 .
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
f luid .
Tire pressure
When tow ing a trai ler, inflate the t ires of your
veh icle 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 trai ler and tire manufac­
turers' specifications.
Lights
Check to make sure both veh icle and trailer
lights are working properly.
Safety chains Be sure tra iler safety cha ins 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 wi ll 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
sepa ration from the hitch.
Driving instructions
Driving with a trailer always requires extra
care and consideration.
To obta in the best poss ible handling of vehicle
and trai le r, p lease note the following:
.. Do not tow a loaded tra iler when your car it ­
self is not loaded .
.. Be especially carefu l 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
Tow ing a loaded trailer with an empty ca r re­
sults in a high ly unstable distribution of
weight . If this cannot be avoided, drive at very
Trailer towing 199
low speeds on ly to avoid the risk of losing
steering contro l.
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 c ircumstances. Whenever poss i­
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 difficu 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 -particularly
when going downhill .
Reduce vehicle speed
immediately if the trail­
er shows the slightest sign of swaying .
Do not
try to stop the swaying by accelerating .
Observe speed limits. In some areas, speeds
for vehicles towing tra ilers are lower than for
regular veh icles .
Always apply brakes early. When driving
downhill, shift into a lower gear to use the en­ gine braking effect to slow the vehicle . Use of
the brakes alone ca n cause them to overheat
and fail.
Coolant tempe rature
The coo lant temperature gauge¢
page 12
must be observed carefully. The coolant tem­
perature can increase if you drive on long in­
cli nes in a low gear at high engine speeds . Re ­
duce your speed immediately if the LEDs in
the top part of the display turn on.
For more information about ind icator lights,
refer to. ¢
page 20 .
A WARNING
Anyone not properly restrained in a mov­
ing vehicle is at a much greate r risk in an
accident. Never let anyone ride in yo ur car
-
•
•
•

206 Checking and Filling
Checking and Filling
Gasoline
Fuel supply
Applies to vehicles: with gasoline engine
Using the right fuel helps keep the environ­
ment clean and prevents engine damage .
Fuel recommendation
The fuel recommended for your vehicle is un­
leaded premium
grade gasoline . Audi recom­
mends using TOP TIER Detergent Gasoline
with a minimum octane rating of91 AKI (95
RON) . For more information on TOP TIER De ­
tergent Gasol ine, please go to the official
website (www .toptiergas.com).
The recommended gasoline octane rating for
your engine can also be found on a label locat­
ed on the ins ide of the fuel filler flap. This rat­
ing may be specified as AKI or RON .
Your vehicle may also be operated using un­
leaded regular gasoline with a minimum oc ­
tane rating of 87 AKI/91 RON . However, using
87 AKI/91 RON octane fuel will slightly re­
duce engine performance.
Use unleaded gasoline only. Unleaded gaso­
line is available throughout the USA, Canada,
and in most European countries. We recom­
mend that you do not take your vehicle to
areas or countries where unleaded gasoline
may not be available.
For more information on refueling your vehi­
cle, see~
page 207.
Octane rating
Octane rating ind icates a gasoline's ability to
res ist engine damaging "knock" caused by
premature ign ition and detonation . Therefore,
buying the correct grade of gasoline is very
important to help prevent possible engine
damage and a loss of engine performance.
Gasoline most commonly used in the United
States and Canada has the following octane
r atings that can usually be found on the filler
pump : - Premium Grade: 91
-96 AKI
- Regular Grade: 87 -90 AKI
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 any fuel w ith octane ratings
lower than 87 AKI or 91 RON otherwise
expensive engine damage w ill occur.
- Do
not use leaded gasoline. The use of
leaded gasoline will severely damage
your vehicle's catalytic converter and its
ability to control exhaust emissions.
Blended gasoline
Applies to vehicles: with gasoline engine
Use of gasoline containing alcohol or
MTBE (methyl tertiary butyl ether)
You may use unleaded gasoline blended with
alcohol or MTBE (commonly referred to as
oxygenates) if the blended mixture meets the
following criteria:
Blend of gasoline methanol (wood alcohol or
methyl alcohol)
-Anti-knock index must be 87 AK I or higher.
- Blend must contain no more than 3% meth-
anol.
- Blend must contain more than 2% co-sol-
vents.
Blend of gasoline and ethanol (grain alcohol
or ethyl alcohol)
-Anti-knock index must be 87 AKI or higher.
- Blend must not contain more than 10%
ethanol.
Blend of gasoline and MTBE
-Anti-knoc k index must be 87 AK I or higher.
- Blend must contain not more than 15%
MTBE.
Seasonally adjusted gasoline

,&_ 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 .
- 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 filling fluids, be sure not to mix the
fluids up. Otherwise severe malfunctions and engine damage will occur.
@) For the sake of the environment
You should regularly check the ground un­ der your vehicle in order to detect leaks
quickly .
If there are visible spots from oil
or other fluids, bring your vehicle to an au­
thorized Audi dealer or qualified repair fa­
cility to be checked.
Opening the hood
The hood is released from the interior.
Fig. 147 Sect ion of the driver's footwell: release lever
Checking and Filling 211
Fig. 148 Rocke r switch un der t he hood
Make sure the wiper arms are not raised up
from the windshield. Otherwise the paint
could be damaged .
The hood can only be released with the driv­
er's door open .
.,. Pull the lever under the instrument panel in
the direction of the arrow¢
fig. 147 .
.,. Raise the hood slightly¢,&. .
.,. Press the rocker switch under the hood up ­
ward
c:> fig. 148. This releases the catch.
.,. Open the hood .
.&, WARNING
Never open the hood when you see that
steam or coolant drips from the engine
compartment- there is a danger of burns!
Wait until no steam or coolant flows out.
- 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 .
Closing the hood
.,. Push the hood down until the force of the
strut is overcome . -
.,. Then lower the hood and let it fall into the
engine hood latch -you do
not have to press
on the hood after it is locked. ¢ ,&. .
.&, WARNING -
A hood that is not completely latched
could fly up and block your view while driv­ ing.

214 Checking and Filling
you have your oil changed, ask your author­
ized Audi Service Advisor.
Under some circumstances the engine oil
should even be changed more frequently .
Change oil more often if you drive mostly
short distances, operate the vehicle in dusty
areas or mostly under stop-and-go traffic con­
ditions, or when you use your vehicle where
temperatures stay below freezing point for
long periods .
Detergent additives in the o il wi ll make fresh
oil look dark after the engine has been run­
ning for a short time. This is normal and is not
a reason to change the oil more often than recommended .
Damage or malfunctions due to lack of
maintenance
It is essential that you change your oil at the
recommended interva ls using only engine oil
that complies with Audi oil standard
VW 502 00. Your Lim ited New Vehicle War­
ranty does not cover damage or malfunctions
due to fa ilure to follow recommended mainte­
nance and use requ irements as set forth in
the Audi Owner's Manual and Warranty
&
Maintenance booklet . Your dea ler will have to
deny warranty coverage un less yo u present to
the dea ler proof in the form of Service or Re­
pair Orders that all schedu led maintenance
was performed in a timely manner.
Engine oil consumption
The engine in your vehicle depends on on ade­
quate amount of oil to lubricate and cool all
of its moving ports.
In order to provide effective lubrication and
cooling of internal engine components , a ll in­
ternal combustion eng ines consume a certain
amount of o il. Oil consumption var ies from
engine to engine and may change significantly
over the life of the eng ine . Typically, engines
with a specif ied break-in period (see
¢
page 193) consume more oil during the
b reak-in period than they consume after oil
consumption has stabilized. Under
normal conditions, the rate o f oil con ­
s u mption depends on the quality and viscosity
of the oil, the RPM (revolut ions per minute) at
which the engine is operated, the ambient
temperature and road conditions. Further fac­
tors are the amount of oil dilut ion from water
co nd ensat ion or fuel residue and the oxida­
t ion level of the oil. As any engine is subject to
wea r as mileage builds up, the oil consump­
tion may increase over time until replacement
of worn components may become necessary.
With a ll these variab les coming into play, no
standard ra te of oil consumpt io n can be es­
tablished or specified. There is no alternative
to regu lar and frequent check ing of the oil lev­
el , see
Note.
If the yellow engine oil leve l warning symbo l
Ill in the instr ument cl uster light s up, you
shou ld check the oil leve l as soon as possible
¢
page 215. Top off the oil at your earliest
convenience
~ page 215.
A WARNING
-~
Before you check anything in the engine
compartment, always read and heed all
WARNINGS¢
page 210.
(D Note
Driving wit h an insufficient oil level is like­
l y to cause severe damage to the engine.
(D Tips
-The oil pressure warning display. is
not an indicator of the oil level. Do not
rely on it. Instead, check the oil level in
your engine at regular intervals, pref­
erably each time you refuel, and always
before going on a long trip .
-If you have the impression your engine
consumes excessive amounts of oil, we
recommend that you consult an author­
ized Aud i dea ler to have the cause of
your concern properly diagnosed. Keep in
mind that the accurate measurement of
oil consumption requ ires great care and
may take some time. An authorized Audi ..,.

The cooling system has been filled at the fac­
tory with a permanent coolant which does not need to be changed. The coolant consists of a
mixture of spec ia lly conditioned water and the
manufacturer's glycol-based coolant addi-
tive Gl3 antifreeze with anticorros ion addi ­
tives (50% fo r USA models; 60% for Canadian
models) . This mixture both assures th e neces­
sary frost protect ion a nd p rotects me tal com ­
ponents in the engine 's coo ling system from
corrosion and scaling.
It al so raises the boil­
ing po int o f the coo lant .
D o no t reduce the concentration of t he coo l­
an t in the summer by ad ding plain w ate r.
The
proportion of coolant additive must be at
lea st 50 % but not more than 60%
to main­
tain ant ifreeze protection and cooling efficien­
cy. If the coolant frost protect ion is too low ,
the coolant cou ld free ze and damage the veh i­
cle heating and eng ine cooling system.
F or yea r-round driv ing, antifreeze is added at
the facto ry for temperatures down to:
- -3 1 °F ( -3 5°C) USA
- -4 0°F ( -4 0°C) Canada.
If you must add coolant, use a m ixture of wa ­
ter and coolant addit ive. M ixing the coolant
addi tive wi th dist illed wate r is recom mend ed.
_& WARNING
Bef ore yo u check any thing in the e ngine
comp artme nt, alw ays re ad and hee d all
WARN INGS
¢page 210.
(D Note
- B efo re winter sets in, have the coolant
c hec ked to see if the c oolan t ad dit ive i n
you r vehi cle is su fficient t o mee t the cl i­
mate cond itions. This is especially impor ­
tant if yo u live in a region whe re the win­
ter is extremely cold. If necessary, in ­
crease the proport ion of coolant additive
to 60%.
- W hen addi ng coolant additive to your
cooling system, remember:
- We recommend using only coolant ad­
ditive Gl2 ++ o r Gl3 ( check t he label)
-
Che cking and Fillin g 21 7
for you r vehi cle. This coolan t additive is
avai lab le at authorize d Audi dea le rs .
Ot her types of antifreeze ca n sig nifi­
cantly reduce corros io n protection. The
res ulting corrosion can cause a loss of
coolant and serio us e ngine da mage .
- Do not add any type of rad iator leak seal­
ant to you r vehicle's engine coolant .
Add ing radiator repair flu id may adverse ­
ly affect t he function and performanc e of
yo ur cooling sys tem and co uld resu lt i n
damage not covered by yo ur New Ve hicle
L imi ted W arranty.
Adding coolant
Fi g. 152 En gine co mpa rtment: markin gs on t he coo l­
an t e xpan sio n t ank
Befo re you check a nyt hing in the eng ine com ­
partment ,
alway s read and heed all WARN­
INGS ¢ page 210.
Checking the engine coolant level
.,. Park yo ur vehicle o n a level su rf a ce .
.,. Switch t he ignition off.
.,. Read t he coolant leve l on the coo lant expan­
sion tank ¢
fig. 152. The coolant leve l must
be between the markings when the engine
in cold. When the engine is warm it can be
slightly above the upper mark ing .
Adding coolant
Req uirement : There m ust be a res idual
amount of coo lant in the expansion tank
c::> Q) .
.,. Le t the engine cool down.
.,. Place a clot h over the coo lant expans ion
tank cap a nd u nscrew the cap co unterclock-
wise
c::> _& . ..,.