2012 AUDI A7 overheating

Cruise control
Switching on
Applies to vehicles: with cr uise contro l
The cruise control system makes it possible to
drive at a constant speed starting at 20 mph
(30 km/h).
0
•
~
0
Fig . 79 Contro l lever with set button
Fig. 80 Display: Selected speed
• Pull the lever to position (D ¢ fig. 79 to
switch the system on.
• Drive at the speed you wish to set.
• Press button @to set that speed.
The stored speed and the indicator light
lff;(1)~1~ (US models) 111 (Canad ian models) ap­
pear in the instrument cluster display
¢ fig. 80. The display may vary, depending on
the type of display in your vehicle . The indica­
tor
light ll in the instrument cluster also illu­
minates.
This information is also shown briefly in the
Head-up Display*.
The speed is kept constant via an engine out­
put adjustment or active brake intervention .
On the road 77
A WARNING
-Always pay attention to traffic even when
the cruise control is switched on. You are
always responsible for your speed and
the distance between your veh icle and
other veh icles .
- For safety reasons, the cruise contro l
should not be used in the city, in stop­
and-go traffic, on twisting roads and
when road conditions are poor (such as
ice, fog, gravel, heavy rain and hydro­
planing) -risk of accident .
- Turn off the cruise control temporarily
when entering turn lanes, highway exit
lanes or in construction zones .
- Please note that inadvertently "resting"
your foot on the accelerator pedal causes the cruise control not to brake. This is
because the cruise control is overridden
by the driver's acceleration.
- If a brake system malfunction such as
overheating occurs when the cruise con­
trol system is switched on, the braking
function in the system may be switched off. The other cruise control functions re­
ma in active as long as the indicato r light
mmlm (US models) !Iii (Canadian mod­
e ls) is on.
(D Tips
The brake lights illuminate as soon as the
brakes decelerate automatically.
Changing speed
Applies to vehicles: wi th cruise co ntrol
• Press lever in the 0 or 0 direction
¢ page 77, fig. 79 to increase or decrease
your speed .
• Release the lever to
save that speed.
Change speed in in crements of 1 mph (1 km/
h) by lightly pressing the lever. If you keep the
lever pressed down, you will a lter your speed
in 5 mph (10 km/h) increments.
You can also press the accelerator pedal down
to increase your speed, e.g . if you want to
II>

ESP includes and/or works together with the
anti-lock brake system (ABS) , brake assist sys ­
tem, anti -slip regulation (ASR) , e lectronic dif­
ferential lock ( EDL) and e lectronic interax le
d ifferential lock* . ESP is swi tched on all the
time. In certain situat ions when you need less
traction , you can switch off ASR by pressing
the button
[ru <::;> page 186, fig . 161 . Be sure
to switch ASR on again when you no longer
n eed less t raction.
Anti-lock br aking s ystem (ABS)
ABS prevents the wheels from locking up
when braking . The veh icle can still be steered
even during hard braking . Apply steady pres­
sure to the brake pedal. Do not pump the ped ­
a l. A puls ing in the bra ke peda l indicates that
the system is he lping you to brake the vehicle.
Brake assist system
The brake assist system can decrease brak ing
d istance.
It increases braking power when the
d river p resses the brake pedal quic kly in emer­
gency situations. You must press and ho ld the
b rake peda l until the situation is over. In vehi­
cles with adaptive cruise control*, the brake
assist system is more sensitive if the distance
detected to the vehicle ahead is too small.
Anti -slip regulati on (ASR )
ASR reduces engine power when the drive
wheels begin to spin and adapts the force to
the road conditions. This makes it easier to
start, accelerate and drive up hills .
Electronic differential lock (EDL )
The ED L brakes wheels that are spinn ing and
transfers the drive power to the other drive
wheel or whee ls if the vehicle is equipped with
all-whee l drive* . This function is available up
to about 75 mph (120 km/h).
I n extreme cases, ED L automat ica lly switches
off to help keep the brake on the braked whee l
from overheating . EDL will switch on again au ­
tomatically when conditions have returned to
normal.
Int ellig ent technolog y 185
Electronic intera xle differ ential l ock */
s el ecti ve w heel torque cont rol *
The electronic interaxle differential lock (front
whee l drive) or the se lective whee l torque
control (all-wheel dr ive) operates when dr iv­
ing through curves . The front wheel on the in­
s ide of the curve or both wheels on the inside
of the curve are braked selectively as needed .
T his min imizes sliding in the front wheels and
allows for more p recise d riving through
curves . T he applicable system may no t acti­
vate when driv ing in wet or snowy conditions.
A WARNING
-
- ESP , ABS, ASR, EDL and the e lectronic in­
teraxle diffe rential lock function* cannot
overcome the laws of physics. This is es­
pecially important on slippery or wet
roads . If the systems begin acting to sta­
bilize your veh icle, you shou ld immedi­
ately change you r speed to match the
road and traffic cond itions. Do not let
the increased safety provided by these
systems tempt you to take risks. Do ing
so will increase the risk o f a loss of vehi ­
cle control, collision and serious persona l
inju ries.
-A lways adapt your speed to road, traffic
and weather conditions . The risk of los ­
ing control of the vehicle increases when
driving too fast, espec ially through
curves and on slippery or wet roads, and
when dr iv ing too close to vehicles up
ahead . ESP, ABS, the brake ass ist system,
EDL, ASR and the e lectronic interax le dif­
fe rential lock fu nction* cannot prevent
coll is ions .
- Always accelerate with spec ial care on
even, smooth su rfaces such as those that
are wet or covered with ice and snow.
The drive wheels can spin even with these assistance systems that cannot al­
ways he lp to red uce the risk of loss of ve -
hicle control. .,.
•
•

Catalytic converter
It is very important that your emission con­trol system (catalytic converter) is function­
ing properly to ensure that your vehicle is run­
ning in an environmentally sound manner .
.. Always use lead-free gasoline¢ page 211,
Fuel supply.
.,. Never run the tank down all the way to
empty.
.,. Never put too much motor oil in your en-
gine
¢ page 221, Adding engine oil~-
.,. Never try to push- or tow-start your veh icle.
The catalytic converter is an eff icient "clean­
up" device built into the exhaust system of
the vehicle . The catalytic converter burns
many of the pollutants in the exhaust gas be ­
fore they are released into the atmosphere.
The exclusive use of unleaded fuel is critically
importa nt for the life of the cata lytic convert­
e r and proper functioning of the engine.
A WARNING
-
- Do not park or operate the vehicle in
areas where the hot exhaust system may
come in contact with dry grass, brush,
fuel spill or other material which can cause a fire.
- Do not apply additional undercoating or
rustproofing on or near the exhaust
man ifold, exhaust pipes, catalytic con­
verter or heat shields. During driving, the
substance used for undercoating cou ld
overheat and cause a fire.
0 Note
- Be aware that just one tank filling with
leaded fuel will already seriously de­
grade the performance of the catalytic
converter.
- Do not exceed the correct engine oil level
¢ page 221.
-Do not drive until the fuel tank becomes
completely empty. The eng ine could mis­
fire . U nburned fuel could a lso get i nto
Dri vin g and en vironm ent 193
the exhaust system and this cou ld cause
the catalytic converter to overheat .
- Do not switch off the ignit ion while the
vehicle is mov ing.
- Do not continue to ope rate your veh icle
unde r these conditions, as othe rwise fuel
can reach the catalytic converter. This
co uld result in overheating of the con­
verter, requir ing its replacement .
- To assure efficient operation of the Emis ­
sion Control System:
- H ave your vehicle maintained prope rly
and in accordance w ith the se rv ice rec­
ommendat ions in you r Warranty &
M aintenance boo klet.
- L ack of prope r maintenance as we ll as
improper use of the vehi cle w il l impair
the function of the em ission contro l
system and could lead to damage .
@ For the sake of the environment
Even when the Emiss ion Control System is
operat ing properly, the exha ust gas can
have a sul fur -li ke exhaust gas smell under
some operating states . This depends on
the sulfur content of the fuel being used .
Using a different brand of fue l may help,
or filling the tank with lead-free super
grade gasoline .
Avoid damaging the
vehicle
When you are drivi ng on poo r roads, or over
c ur bs, s teep ramps, etc., ma ke certai n that
low -lying parts s uch as spoilers and exhaust
system pa rts do not bottom o ut and get dam­
aged.
T h is is espec ially true for veh icles w ith low­
s lung chassis (spor ts chassis)* and fully load­
ed vehicles. •
•

Engine cooling system
Coolant
The engine coolant performs two functions: it
keeps the engine from overheating and it pro ­
tects the engine from freezing in the winter .
The cooling system is sealed and generally re­
quires little attention .
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 water and the manufacturer's gly ­
col-based coolant additive G12++ antifreeze
with anticorrosion additives (50% for USA
models; 60% for Canadian models). This mix­
ture both assures the necessary frost protec­
tion and protects metal components in the
engine's cooling system from corrosion and
scaling. It also raises the boiling point of the
coolant.
Do not reduce the concentration of the cool­
ant in the summer by adding plain water.
The
proportion of coolant additive must be at
least 50% but not more than 60%
to main­
tain antifree ze protection and cooling efficien­
cy. If the coolant frost protection is too low,
the coolant could freeze and damage the vehi ­
cle heating and engine cooling system.
For year-round driving, antifreeze is added at
the factory for temperatures down to:
- -31 °F ( -3 5 °C) USA
- -40 °F ( - 40 °C) Canada.
You can mix the G12 ++ coolant additive with
other additives (G12+ or G12). Always check
with your authorized Audi dealer.
& WARNING
Before you check anything in the engine
compartment, always read and heed all
WARNINGS
~ .&. in Working in the engine
compartment on page 216.
(D Note
- Before winter sets in, have the coolant
checked to see if the coolant additive in
Checking and filling 223
your vehicle is sufficient to meet the cli­
mate conditions. This is especially impor­
tant if you live in a region where the win­
ter is extremely cold. If necessary, in­
crease the proportion of coolant additive
to 60% .
- When adding coolant additive to your
cooling system, remember :
- We recommend using only coolant ad­
ditive G12++ (check the label) for your
vehicle. This coolant additive is availa­
ble at authorized Audi dealers. Other
types of antifreeze can significantly re­
duce corrosion protection. The result­
ing corrosion can cause a loss of cool­
ant and serious engine damage.
- Do not add any type of radiator leak seal­
ant to your vehicle's engine coolant.
Adding radiator repair fluid may adverse­
ly affect the function and performance of
your cooling system and could result in
damage not covered by your New Vehicle
Limited Warranty.
Checking the engine coolant level
The engine coolant level can be checked with
a quick glance.
M AX f
MINf
Fig. 172 Engine compar tment: markings on the coo l­
an t expa nsion tank
Before you check anything in the engine com­
partment,
always read and heed all WARN­
INGS ¢.&, in Working in the engine compart­
ment on page 216 .
"' Park your vehicle on a level surface .
"' Switch off the ignition.
"' Read the engine coolant level from the
coolant expansion tank~
fig. 172. With a