2015 AUDI A6 Red light

M N
0 <.J 'SI: ,...., \!) 1.1"1 ,...., 1.1"1 ,....,
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. ..,.
•
•

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.

232 Checking and filling
@ For the sake of the environment
Because of the problem of proper disposal
of brake fluid as we ll as the special tools
required and the necessary expertise, we recommend that you have the brake fluid
changed by your author ized Audi dealer.
Battery
General information
Under normal operating conditions, the bat­
tery in your Audi does not need any mainte­
nance. With
high outside temperatures or
long daily drives we recommend that you have
the electro lyte level checked by a service fa­
cility . The electrolyte level should also be
checked each time the battery is charged
¢ page 234.
Have the battery checked when you take your
vehicle in for service . You are well adv ised to
replace a battery that is older than 5 years .
With certain types of airbag deployment, the battery is disconnected from the vehicle elec­
tr ical system for safety reasons¢
& in Re­
pair, care and disposal of the airbags on
page 161.
Disconnecting the battery terminals
Some vehicle functions (power window regu­
lators, for example) are lost if the battery ter­
minals are disconnected. These functions have
to be relearned after the battery terminals are
connected again. To prevent this , the battery
should only be disconnected from the vehicle
e lectrica l system when absolutely necessary
for repairs.
Vehicles not driven for long periods
If you do not drive your vehicle over a period
of severa l days or weeks, electrical compo­
nents are gradually cut back or switched off.
This reduces energy consumption and main­
tains starting capabi lity over a longer period
¢page 198. Some of the convenience func­
tions may not operate, such as the interior
lights or power seat adjustment. The conven- ience
functions will be available again when
you switch on the ignition and start the en­ gine.
Winter operation
During the winter months, battery capac ity
tends to decrease as temperatures drop. This
is because more power is a lso consumed whi le
starting, and the headlights, rear window de­
fogger, etc., are used more often.
Avoid unnecessary power consumption, par­
ticu larly in city traffic or when traveling only
short distances. Let your authorized Audi
deale r check the capacity of the vehicle bat ­
tery before winter sets in¢
page 234 . A well
charged battery will no t only prevent star ting
problems when the weather is cold, but will
also last longer .
@ Tips
If your vehicle is left standing for several
weeks at extremely low temperatures, the
vehicle battery shou ld be removed and
stored where it w ill not freeze. This will
prevent it from be ing damaged and having
to be replaced .
Working on the battery
Be especially careful when working on or near
the battery.
The battery is located in the luggage compart­
ment under the floor . Before you check any­
thing in the luggage compartment,
read and
heed all WARNINGS
¢ .&, .
Always heed the safety warnings , when work­
ing on the vehicle battery or the vehicle elec­
t rical system to prevent injury.
The following WARNINGS are very
important when working on the battery:
Always heed the following WARNING SYM-
BOLS and safety precautions when working
on the battery.
®
Always wear eye protection.

M N
0 <.J 'SI: ,...., \!) ..,.,
,...., ..,., ,....,
-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-
•
•

246 Tires and wheel s
If you wish to improve comfort See the illustration ¢ fig. 195
when operating the vehicle at for the locati on of the labe l on
normal load (up to 3 occu -driver's side B -pillar (color of
pants), you can adjust tire the actual label and exact loca-
pressures to those specified tion on the vehic le will vary
for normal vehicle load. Before slight ly) .
operat ing the vehicle at maxi -Note that the following table is
mum load , you must increase accurate at the time of going to
the ti re pressu res to those press and is subject to change .
specified for maximum vehicle In the event of discrepancies,
load¢&. the tire pressure labe l is locat-
Bear in mind that the tire pres- ed on the driver's side 8-pi llar
sure monitoring system can on -always takes precedence .
ly monitor the tire pressures The table below lists the rec-
you have stored . The system
ommended cold tire inflation
does not recogn ize the load
pressures for the Audi model
condition of your vehic le.
covered by your Owner's Litera-
T he effectiveness of the tire ture at the vehicle's capacity
pressure monitoring system weight and the tire sizes instal -
will be impaired if you store led on the respective mode ls as
normal load pressures but then original equipment, or as a fac-
operate the vehicle at its maxi- tory option.
...
mum load¢&.

250 Tires and wheels
amount of luggage into ac-Never exceed the maximum in-
count when adjusting tire pres-flation pressure listed on the
sure for a trip -even one that tire sidewall for any reason.
you would not consider to be
Remember that the vehicle
"long." See
q page 2 52, Tires manufacturer, not the tire man-
and vehicle load limits for more ufacturer, determines the car-
important information. rect tire pressure for the tires
Always use an accurate tire on your vehicle.
pressure gauge when checking It is important to check the tire
and adjusting inflation pres- pressure when the tires are
sures. Check all of the tires and cold.
be sure not to forget the spare -Read the required tire pres-
tire. If the pressure in any tire is
sure from the tire pressure la-
too high when the tire is "cold,"
bel. The tire pressure label is
let air out of the tire slowly
located on the driver's side B-
with the edge of the tire gauge
pillar.
and keep checking the pressure
-Turn the valve stem cap coun-
until you reach the pressure
ter-clockwise to remove it
that is correct for the load (pas-
from the tire valve.
sengers and luggage) and kind
-Place the air pressure gauge
of driving you plan to do .
on the valve.
If the pressure in any tire is too -The tire pressures should only
low, note the difference be-
be checked and adjusted when
tween the pressure in the cold the tires are cold. The slightly
tire and the pressure you need
raised pressures of warm tires
and add the air that you need to must not be reduced.
reach the correct pressure for -Adjust the tire pressure to the
the vehicle load (passengers load you are carrying.
and luggage) for the tires on
-Reinstall the valve stem cap
your vehicle as listed on the on on the valve.
...
your vehicle and in this manual
and the kind of driving you plan
to do.

268 Tires and wheels
Tire pressure indicator appears
The tire pressure indicator in the instrument
cluster informs you if the tire pressure is too
low or if there is a system malfunction.
Fig. 200 Display : und erinflatio n warn ing
Fig. 201 Display: Syste m malfunction
Using the ABS sensors , the tire pressure moni­
toring system compares the tire tread circum­
ference and vibration characteristics of the in­
dividual tires.
If the pressure decreases in one
or more tires, this is indicated in the instru­
ment cluster with a warning symbol
[9] and a
message ¢
fig. 200.
The tire pressure monitoring system must be
reset via MMI each time the pressures are ad­
justed (e. g. when switching between partial
and full load pressure) or after changing or re­
placing a tire on your vehicle¢
page 269 . The
TPMS indicator only monitors the tire pres­
sure that you have previously stored. You can
find the recommended tire pressures for your vehicle on the label on driver's side 8-pillar
¢page 244.
Tire tread circumference and vibration charac­
teristics can change and cause a tire pressure
warning if:
- the tire pressure in one or more tires is too
low, -
the tire has structural damage,
- th e tire pressure was changed, wheels rotat-
ed or replaced but the TPMS was not reset
¢page 269.
- the spare tire* is mounted .
Warning symbols
[9] Loss of pressure in at least one tire¢&. .
Check the tire or tires and replace or repair if
necessary. The indicator light
[9] in the instru­
ment cluster also illuminates
¢page 12.
Check/correct the pressures of all four tires
and reset TPMS via MMI.
Ill (Tire Pressure Monitoring System ) Tire
pressure! System malfunction . Iflll appears
after switching the ignition on or while driving
¢
fig. 201 and the indicator light [9] in the in­
strument cluster blinks for approximately one
minute and then stays on, there is a system
malfunction . Attempt to store the correct tire
pressure ¢
page 269. If the indicator light
does not turn off or if it turns on shortly
thereafter, immediately drive your vehicle to
an authorized Audi dealer or authorized repair
facility to have the malfunction corrected.
A WARNING
- If the tire pressure indicator appears in
the instrument cluster display, one or
more of your tires is significantly under­
inflated. Reduce your speed immediately
and avoid any hard steering or braking
maneuvers. Stop as soon as possible and
check the tires and their pressures. In­
flate the tire pressure to the proper pres ­
sure as indicated on the vehicle's tire
pressure label¢
page 244 . Driving on a
significantly under-inflated tire causes
the tire to overheat and can lead to tire
failure. Under-inflation also is likely to
impair the vehicle's handling and stop­
ping ability.
- The driver is responsible for maintaining the correct tire pressures. You must
check the tire pressures regularly. ..,

M N
0 <.J 'SI: ,...., \!) ..,.,
,...., ..,., ,....,
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>
•
•