2015 AUDI A6 check engine light

224 Checking and filling
Engine compartment
Engine compartment overview
These are the most important items that you can check.
Fig. 188 Typ ical layout for contai ners and eng ine o il filler cap
(D Jump start point(-) with hex
head screw .... ............. 234, 283
@ Jump start point(+) under a cov-
er .. .. ............... .... . 234,283
@ Brake fluid reservoir ((0)) . . . . . 231
© Engine oil filler cap ( ®
® Coolant expansion tank (-L) ... 228
Windshield/headlight washer
. (' " ) container O ............ . . 235
The engine oil filler neck (item @) may be lo­
cated in a different area depending on the ver­
sion of the engine.
~ WARNING
Before you check anything in the engine
compartment, always read and heed all
WARNINGS
¢ &. in Working in the engine
compartment on page 222.
-
Engine oil
Engine oil specifications
The engine oil used must conform to exact
specifications.
The service interval display in the instrument
cluster of your vehicle will inform you when it
is time for an oil change. We recommend that
you have your oil changed by an authorized Audi Serv ice Advisor.
If you have to top
off the oil between oi l
changes, use the Audi oil quality standard
specified in the table.
Audi oil quality standard
Gasoline
VW 502 00 or
engine vw 504 00
Diesel vw 507 00
engine

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Using the proper engine oil is important for
the functionality and service life of the en­
gine. Your engine was factory -filled with a
high-quality oil which can usually be used
t h roughout the entire year.
Your Limited New Vehicle Warranty does not cover damage or malfunctions due to
failure to follow recommended mainte­
nance and use requirements as set forth in
the Audi Owner's Manual and Warranty
&
Maintenance booklet .
- Use only a high quality engine oil that ex­
pressly complies with the Audi oil quality
standard specified for your vehicle's en­
gine . Using any other oil can cause seri­
ous engine damage.
- Do not mix any lubricants or other addi­
tives into the engine oil. Doing so can
cause engine damage.
If you need to add oil and there is none
available that meets the Audi oil quality
standard your engine requires, you may
add a total of no more than 0.5 quart/liter
of a high-quality "synthetic"oil that meets
the following specifications.
- Vehicles with gasoline engine: ACEA A3
or API SM with a viscosity grade of
SAE 0W-30, SAE SW-30 or SA E SW-40.
- Vehicles with diesel engine: ACEA C3 or
API CF with a viscosity grade of
SAE 0W-30 or SAE SW-30.
- For more information about engine oil
that has been approved for your vehicle, please contact either your authori zed
Audi dealer or Audi Customer Relations
at 1 (800) 822 -2834 or visit our web site
at www.audiusa.com or
www.audicanada .ca.
Checking and filling 225
Engine oil consumption
T he engine in your vehicle depends on an ade­
quate amount of oil to lubricate and cool all
of its moving parts .
In order to provide effec tive lubrication and
cooling of internal engine components, all in ­
ternal combustion engines consume a certain
amount of oil. Oil consumption varies from engine to engine and may change significantly
over the life of the engine. Typically, engines
with a specified break-in period (see
c::> page 200) consume more oil during the
break-in period than they consume after oil
consumption has stabili zed.
Under normal conditions , the rate of oil con­
sumption depends on the quality and viscosity
of the oil, the RPM (revolutions per minute) at
which the engine is operated, the ambient
temperature and road condi tions. Further fac­
tors are the amount of oil dilution from water
condensation or fuel residue and the oxida­
tion level of the oil. As any engine is subject to
wear as mileage builds up, the oil consump­
tion may increase over time until replacement
of worn components may become necessary.
With all these variables coming into play, no
standard rate of oil consumption can be es ­
tablished or specified . There is no alternative
to regular and frequent checking of the oil lev­
el , see
Note.
If the yellow engine oil level warning symbol
in the instrument cluster
II lights up, you
should check the oil level as soon as possible
c::> page 226. Top off the oil at your earliest
convenience
c::> page 226.
A WARNING
--
Before you check anything in the engine
compartment, always read and heed all
WARNINGS
c::> & in Working in the engine
compartment on page 222.
(D Note
Driving with an insufficient oil level is like-
ly to cause severe damage to the engine. .,.
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Before you check anything in the engine com­
partment,
al ways r ead and heed all W ARN­
ING S r=;, A in Working in the engine compart­
ment on page 222.
.. Park your vehicle on a level surface.
.. Switch
off the ignition .
.. Read the eng ine coolant leve l from the cool­
ant expansion tank¢
fig. 191, ¢ page 224,
fig. 188.
With a cold engine, the coolant
level should be between the "min" and
"max" markings. When the engine is warm,
the leve l may be slightly above the "max"
mark ing .
The location of the coolant expans ion tank
can be seen in the engine compartment illus­
tration ¢
page 224.
To obta in an accurate read ing, the engine
must be switched
off.
The expansion tank in your vehicle is equipped
with an electric coolant level sensor.
When the coo lant level is too low, the warning
light in the Auto-Check System
¢ page 16 will
illum inate until yo u add coolant and the level
has been restored to normal. Even though
there is an electric coo lant level sensor, we
still recommend you check the coolant leve l
from time to time .
Coolant loss
Coolant loss may indicate a lea k in the cooling
system. In the event of coolant loss, the cool­
ing system should be inspected immediately
by your authorized Audi dealer . It is not
enough merely to add coola nt.
In a
sealed system, losses can occur only if
the boiling point of the coolant is exceeded as
a result of overheat ing .
A WARNING
The coo ling system is unde r pressure and
c an get ve ry ho t. Reduce the risk of s cald­
ing from h ot coolan t by followi ng these
steps .
- T urn
off the engine and allow it to coo l
down.
Checkin g and fillin g 229
-Protect your face, hands and arms from
escaping flu id and steam by covering the
cap with a large, th ick rag.
- Turn the cap slowly and very carefully in
a counter-clockwise d irect ion while ap­
plying lig ht, downward pressure on the
top of the cap .
- To avo id being burned, do not sp ill anti­
freeze or coolant on the exhaust system
or hot engine parts. Under certa in cond i­
tions, th e ethylene glycol in engine coo l­
ant can catch fire.
(D Note
Do not add any type of radiator leak sea l­
ant to your ve hicle's engine coolant. Add-
i ng radiator repa ir flui d may adverse ly af­
fe ct the funct ion a nd pe rfo rma nce of you r
co oling system and could re sult in damage
not covered by your New Vehicle Limi ted
War ranty.
Adding coolant
Be very careful when adding engine coolant.
Before you ch eck anyth ing in the eng ine com­
partment,
alway s re ad and heed all WARN­
INGS ¢ A in Working in the engine compar t­
ment on page 222.
.. Requirement: The re must be a residua l
amount of coolan t in the expansion ta nk
¢(D .
.. Tu rn off the engine.
.. Let the engine cool down.
.. Place a thick rag ove r th e coo lant expansion
tank
¢ page 228, fig . 191 and carefully
twist the cap counte r-clockwise ¢.&, .
.. Add coo lant m ixed in the correct ratio
¢
page 228, Coolant up to the MAX mark ­
ing .
.. Make s ure that the flu id leve l remains sta-
b le. Add more coo lant if ne cessary.
.. Twis t the cap o n again
t ightly.
Replacement engine coo lant must confo rm to
exact spec ificat ions
r=;, page 228, Coolant. ..,.
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•

230 Check ing and filling
We recommend using on ly coo lant addi-
tive
Gl2++, Gl3 or in an emergency Gl2 +. Do
not use a different additive . In an emergency
use plain water unt il you can get the correct
additive and can restore the correct ratio. This
should be done as soon as possible .
If you have lost a cons iderable amount of
coolant, then you should add co ld antifree ze
and cold water only when the engine is co ld.
A lways use
new engine coolant when refilling.
Do not fill coolant above the "MAX" mark. Ex­
cess coolan t will be forced out through the
p ressure relie f valve in the cap when the en ­
gine becomes hot.
A WARNING
- The coo ling system is under press ure and
can get very hot. Reduce the risk of
sca lding from hot coolant by following
these steps.
- Turn off the eng ine and a llow it to cool
down.
- Protect your face, han ds and arms from
escap ing fl uid and steam by cover ing
the cap with a large, thick rag.
- Tur n the cap slowly and very c arefully
in a counter-clockwise d irect ion while
applying light, downward press ure on
the top of the cap .
- To avo id being burned, do not sp ill an ­
tifreeze or coolant on the exhaust sys ­
tem or hot engine parts. Under certain
conditions, the ethylene glyco l in en­
g ine coolant can catch fire.
- Antifreeze is poisonous. Always store an­
t ifreeze in its or iginal container and well
out of the reach of children.
- If you drain the coolant, it must be
caught and safely stored in a proper con­
tainer clear ly marked "poison".
- Do not add coolant if the expansion tank
is empty. A ir could enter the cooling sys­
tem and damage the eng ine. If this is the case, do not cont
inue driving . Seek
professiona l assistance .
- Coo lant poll utes the environmen t and
co uld cause an engine fire . Excess cool­
ant will be forced out thro ugh the pres­
sure relief valve in the cap when the en­
gine becomes hot.
- If, in an eme rgency, only wate r can be
added, the correct ratio between water
and antifreeze
c::> page 228 must be re­
stored as soon as possible .
@ For the sake of the environment
Drained coolant should not be reused . A l­
ways d ispose of used coolant while observ­
i ng all environmental regulations .
Radiator fan
The radiator fan switches on automatically by
itself.
An a uxiliary electric radiator fan switches on
and off depending on coolant temperature
and other vehicle operat ing condit ions .
After yo u switch the engine off, the auxi liary
fan can continue r unning for up to 10 minutes
- even w ith the ignition off . It can even switc h
on again later by itself
c::> .& , if
- the temperature of the engine coo la nt rises
due to the heat build- up from the engine in
the engine compartment, or
- the engine compa rtment heats up because
the vehicle is parked in intense sunlight.
A WARNING
- To reduce the risk of personal injury nev­
er touch the radiator fan.
- The a uxiliary electric fan is temperat ure
controlled and can sw itch on suddenly
even when the engine is not ru nning .
- The a uxiliary radiator fan sw itches on a u­
tomatically when the engine coo lant
reaches a certai n temperature and will
continue to run until the coolant temper­
ature drops.

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"' rl
Brake fluid
Checking brake fluid level
Fig. 192 Engine co mpa rtment: cove r on the b rake f luid
reservo ir
Before you check anything in the engine com­
partment,
al ways r ead and h eed all WARN·
ING S ¢ &. in Working in the engine compart­
ment on page 222.
.. Read the brake fluid level from the brake
fl uid reservoir¢
fig. 192, ¢ page 224,
fig. 188 .
The brake f luid level must be be­
tween the "MIN" and "MAX" markings .
The location of the brake flu id reservo ir can be
seen in the engine compa rtment illust rat ion
¢ page 224.
The fluid level may drop slightly after some
time due to the automatic adjustment of the brake pads. This is not cause for alarm.
If the brake fluid level falls
considerably be­
low the "MIN" mark, the brake wa rning/indi­
cator ligh t. (U .S. models) . (Canad ian
models) will come on ¢
page 15. Do not con­
tinue to operate the vehicle. The comp lete
brake system shou ld be thoroughly checked
by an authorized A udi dealer or other quali­
fied facility and the cause corrected.
If the
br ake fluid level is too low, the brake warn ing/
indicator light w ill illuminate. Contact an au·
thor ized Audi dealer
imm ediately .
Checkin g and fillin g 231
Changing brake fluid
Have the brake fluid changed by an experi·
enced technician .
Brake fluid absorbs mois ture from the air. If
the wa ter content in the brake fluid is too
high , corrosion in the brake system may result
after a period of time . The boiling point of the
brake flu id will also dec rease considerably and
decrease braking pe rformance.
Therefore, the brake fluid must be changed
ev ery two years. Always use new brake flu id
which conforms to Federal Motor Vehicle
Standard "F MVSS 116 DOT 4".
The brake fluid reservo ir can be d iff icult to
reach, the refore, we recommend that you
have the brake fluid changed by your author­
i zed
Audi d ealer . Your dealer has t he correct
tools, the right brake fl uid and t he know-how
to do this for you .
A WARNING
-.
-Brake fluid is poisonous . It must be stor­
ed only in the closed original container
out of the reach of children!
- Brake failure can resu lt from o ld or inap­
propriate brake f luid. Observe these pre­
cautions:
- Use only brake fluid that meets SAE
spe cificat ion
J 1 7 03 and conforms to
Federa l Moto r Ve hicl e Standard 116.
Always check with yo ur authorized Audi
dealer to make sure yo u are using the
correct bra ke fluid. The correct type of
brake f luid is also indicated on the
brake f luid reservoir.
- The brake fluid must be new. Heavy use
of the brakes can cause a vapor lock if
the brake fluid is left in the system too
l ong . This can seriously affect the effi ­
c iency of the brakes as well as your
safety. Th is cou ld resu lt in an accident.
(D Note
Brake fluid will damage the paint of your
vehicle .

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-Charge the battery in a well ventilated
area. Keep away from open flame or elec­
trical spark. Do not smoke. Hydrogen gas generated by the battery is explosive.
- To reduce the danger of explosion, never
connect or disconnect charger cables
while the charger is operating.
- Fast charging a battery is dangerous and
should only be attempted by a compe­
tent technician with the proper equip­
ment.
- Battery acid that may spill during charg­
ing should be washed
off with a solution
of warm water and baking soda to neu­
tralize the acid.
(D Note
Never use a fast charger as a booster to
start the engine. This will seriously dam­
age sensitive electronic components, such
as control units, relays, radio, etc., as well
as the battery charger.
Battery replacement
The new battery must have the same specifi­
cations and dimensions as the original equip­
ment battery.
Intelligent energy management in your vehi­
cle is responsible for distributing the electri­
cal energy throughout your vehicle
qpage 198. The intelligent energy manage­
ment system will keep the engine battery
charged better than vehicles without this sys­
tem. To make sure the additional electrical en­
ergy is available once again after you have
changed the battery, we recommend that you install batteries of the same type and manu ­
facture only (the same as those installed at
the time your vehicle was delivered). Specifi­
cations are listed on the battery housing. Your
authorized dealer must code the battery in
the energy management system to enable you
to use the energy management functions cor­
rectly after replacing the battery.
Checking and filling 235
The new battery must have the same capacity,
voltage (12-volts), amperage, construction and plug sealing.
When installing the battery, make sure the ig­ nition and all electrical consumers are switch­
ed off.
(D Note
Make sure the ventilation hose on the side
of the battery is connected, otherwise
fumes or battery acid can leak out.
- Vehicles with the Start-Stop-System* are
equipped with a special cycle-proof AGM
battery. Installing a different type of
battery can cause problems in the vehi­
cle electrical system. When replacing the
vehicle battery, always install one with
the same specifications as the original
battery.
@ For the sake of the environment
Because of the problem of proper disposal
of a battery, we recommend your author­
ized Audi dealer change the battery for
you. Batteries contain sulfuric acid and
lead and must always be disposed of prop­
erly in compliance with all environmental
regulations. Disposing of vehicle batteries
improperly is very dangerous to the envi­
ronment.
Windshield/headlight*
washer container
Fig. 194 E ng in e compart ment : cov er on th e w in ds hield
and headl ig ht* washer f luid reservoir
II-
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,...., ..,., ,....,
A WARNING 1=
You or your passengers could be injured
while changing a wheel if you do not fol­
low these safety precautions:
- If you have a flat tire, move a safe dis­
tance off the road. Turn off the engine,
turn the emergency flashers on and use
other warning devices to alert other mo­
torists.
- Make sure that passengers wait in a safe
place away from the vehicle and well
away from the road and traffic.
- To help prevent the vehicle from moving
suddenly and possibly slipping off the
jack, always fully set the parking brake
and block the wheel diagonally opposite
the wheel being changed. When one
front wheel is lifted off the ground, plac­
ing the Automatic Transmission in P
(Park) will
not prevent the vehicle from
moving.
- Before you change a wheel, be sure the
ground is level and firm. If necessary,
use a sturdy board under the jack.
- Always store the vehicle tool kit, the jack
and the replaced tire in the luggage com­
partment
¢ page 132.
{!) Tips
Before changing the wheel, you must acti­
vate the jacking mode, so that the auto­ matic controls for the Adaptive Air Sus­
pension* do not make it more difficult to
lift the vehicle with the jack¢
page 2 75.
Changing a wheel
When you change a wheel, follow the se ­
quence described below step-by-step and in
exactly that order .
1. Activate the vehicle jack mode*
c::;. page 275.
-
2. Remove the decorative wheel cover* . For
more details see also
¢page 274, Deco­
rative wheel covers
or ¢ page 2 7 4,
Wheels with wheel bolt caps.
3. Loosen the wheel bolts¢ page 274.
What do I do now? 273
4.
5.
6.
7.
8.
9.
Locate the proper mounting point for the
jack and align the jack below that point
¢page 275.
Raise the car with the jack ¢page 275.
Remove the wheel with the flat tire and
then install
the spare <=> page 2 76.
Tighten all wheel bolts lightly.
Lower the vehicle with the jack .
Use the wheel bolt wrench and
firmly
tighten all wheel bolts¢ page 274 .
10. Replace the decorative wheel cover*.
11. Deactivate the vehicle jack mode* in the
MMI:
ICARI function button > (Car)* sys­
tems
control button > Servicing & checks
> Air susp.: jack mode > Off .
The vehicle jack mode* switches off automati­
cally at speeds above 6 mph (10 km/h).
A WARNING
Always read and follow all WARNINGS and information<=>
A in Raising the vehicle on
page 275
and <=> page 277.
After changing a wheel
A wheel change is not complete without the
doing the following.
.,. Always store the vehicle tool kit, the jack*
and the replaced tire in the luggage com­
partment
c::;. page 132.
.,. Check the tire pressure on the spare wheel
immediately after mounting it.
.,. As soon as possible, have the
tightening
torques
on all wheel bolts checked with a
torque wrench. The correct tightening tor­
que is
90 ft lb (120 Nm) .
.,. Have the flat tire
replaced as soon as possi­
ble.
(D Tips
- If you notice that the wheel bolts are
corroded and difficult to turn while
changing a tire, they should be replaced
before you check the tightening torque.
- Drive at reduced speed until you have the
tightening torques checked.
ll>
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298 Index
AUTO automatic climat e control . ... ... ... ..
71
Automatic headlights ....... .. .... .. 43
climate control . . . . . . . . . . . . . . . . . . . . . 68
Auto Lock . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3
Automatic belt retractor .. ... ..... .. .
139
Automatic climate control
Air vents . .... ........... .... .... ..
7 1
Automatic recirculation . . . . . . . . . . . . . . 72
Opera tion . . . . . . . . . . . . . . . . . . . . . . . . . 70
Setup . .. .. ................ ... .. .. 72
synchron izing .... ......... ... .. .. .. 71
Automatic Shift Lock (ASL) . . . . . . . . . . . 108
Automatic transmission ..... .. .. .. .. . 107
Automatic Shift Lock (ASL) .......... 108
Driving .................... ..... . 109
Emergency mode .......... ... .... . 112
Emergency release .......... .. .... . 113
Kick-down . . . . . . . . . . . . . . . . . . . . . . . . 111
Manual shift program ..... .... .... . 111
Selector lever . . . . . . . . . . . . . . . . . . . . . 107
Automatic wipers .................. .. 48
Auto Safety Hotline ........ .. .. .. .. . 134
Ave rage consumption ....... .. .. .. .. . . 25
Average speed . . . . . . . . . . . . . . . . . . . . . . .
25
Avoid damaging the vehicle .. .. .. .. .. . 201
B
Ba ttery . .. .. ... .. ..... ... .... .. .. . 232
Charging . .. ................ ... ... 234
Important warnings .. .... .. .. .. .. . 232
Jump starting . ........... .. .. .. .. . 283
Locat ion . .. ............. .. .. .... . 232
low ... .. .. .. . ... ....... .. .. .. .. . 198
Replacing the battery ......... .. .. . 235
State of charge ............ ... .... . 198
Winter operation .......... ... .... . 232
Working on the battery ...... .. .... . 232
Before driving ............. .. .. .... . 126
Blended gasoline ........... ... .. .. . 214
Blower (automatic climate control) . . . . . . 71
Blower (climate control) . . . . . . . . . . . . . . . 68
Booster seats ............. .. .. .... .
180
Brake fluid
Changing the brake fluid ............
231
Checking the brake fluid lev el ... .. .. . 231
What is the correct brake fluid level? . . 231
What should I do if the brake fluid warn-
ing light comes on? ................
231
Brake system
Anti- lock braking system ............ .
19
Brake assist system ................ 193
Brake booster .... ............. .... 196
Brake fluid . ..... ................ . 231
Brake fluid specifications for refill and re-
placement .... ... .............. ..
231
Brake pads .. .. .. .......... ...... . 200
Electromechanical parking brake ... .. . 77
Fluid reservoir ... ................ . 231
How does moisture or road salt affect the
brakes? . .. .. .. .. ............. .. ..
195
Warning/indicator lights ............. 15
Worn brake pads symbol . . . . . . . . . . . . . 20
braking guard
Settings .. .. .. .. .. ........... .. .. .
91
Braking guard . .. .. ............. .. .. . 84
Messages . .. .. .. .. ..... ... ... .... . 91
Break-in period .... ................ . 200
Brake pads .... .. ................ . 200
Tires ..... .... ................... 200
Bulbs ...... .. .. .. .. ... .... .... .... 282
C
Californ ia Proposition 65 Warning . .. .. 223
Battery specific ... .......... .... .. 233
Capacities .. .... ............. ...... 290
Engine oil ..... .. .......... ...... . 224
Carbon parts
Cleaning . . . . . . . . . . . . . . . . . . . .
211, 212
Car carrier
Transpo rting your vehicle ...........
287
Care ...... .... ... .. .............. . 209
Cargo area ...... .. .. .............. . 132
Cargo net . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Catalytic converter . ............. .... 201
Center armrest
Cockpit ...........................
55
Central locking .... ............. .... . 33
Emergency locking ............. .... .
37
Certification .. .. .. ..... ........... . 295
Changing a wheel .. ................ . 272
Changing engine oil ... .. ... ..... .. .. 227