2015 AUDI A8 radiator cap

16 Instruments and warning/indicator lights
If the engine coolant level is correct, then the
radiator fan may be the cause of the malfunc­
tion.
• Coolant temperature too high! Please let
engine run with vehicle s tationary
If the indicator light turns on and the mes­
sage appears, let the engine run at idle for a
few minutes to cool down.
A WARNING
- If your vehicle should break down for
mechanical or other reasons, park at a
safe distance from moving traffic, turn
off the engine and turn on the hazard
warning lights¢
page 47, Emergency
flasher .
-Never open the hood if you see or hear
steam or coolant escap ing from the en­
gine compartment -you risk being scald­
ed . Wait until you can no longer see or
hear steam or coo lant escaping.
- The engine compartment of any veh icle
is a dangerous area. Before you perform
any wor k in the engine compartment,
turn of the eng ine and allow it to cool.
Follow the warning sticke rs
¢page 228.
(D Note
Do not continue driving if the . symbol
illuminates. There is a malfunction in the
engine cooling system -you could damage
your eng ine.
0 Battery
This warning/indicator light detects a mal­
function in the generator or in the vehicle's
electrical system .
The. warni ng/indicator light illuminates
when you switch on the ignition and must go
out after the engine has started .
• Alternator fault: Battery is not being
charged
If the indicator light turns on and the mes ­
sage appears, there is a malfunction in the
generator or vehicle electr ica l system . Drive to
your authorized Audi dealer or quali­
fied workshop immediate ly. Because the vehi­
cle battery is discharg ing, turn off all unnec ­
essary electrical equipment such as the rad io .
Seek professional assistance if the battery
charge level is too low .
r•j Low battery charge: battery will be
charged while driving
If the indicator light turns on and the mes­
sage appears, there may be limited starting
ability.
If this message turns off after a litt le while,
the battery charged enough while driving.
If the message does not turn off, have your
authorized Aud i dealer or qualified workshop
correct the malfunction.
L'h Engine
• Engine stopped: No power steering and
brake support.
The re is a malfunction in the engine or in the
fuel supply system.
A large amount of steering and braking force
is required when driving a rolling vehicle with
the engine stopped. Tr y to stop a rolling vehi­
cle carefu lly on the side of the road. See your
authorized Audi dealer or qualified repair fa­
cility.
A WARNING
-If the engine stops while driving, a large
amount of braking force is required. This
in creases the r isk of an accident. As long
as the vehicle rolls with the ignit ion
switched on and there is enough battery
cha rge, the power steering will sti ll work.
If not, a large amount of steering force is
r equired.
-

228 Checking and filling
Checking and filling Engine hood
Releasing the engine hood
The engine hood is released from inside the
vehicle .
Fig. 197 Driver foo twell: release lever
Fig. 198 Rocker switch un der the hood
Make sure the wiper arms are not raised up
from the windshield. Otherwise the paint
could be damaged.
.,. Pull the lever under the instrument panel in
the direction of the arrow
¢ fig. 197.
.,. Raise the hood slightly¢,&. .
... Press the rocker switch under the hood up­
ward ~
fig. 198. This releases the catch.
• Open the hood.
&_ WARNING
Hot engine coolant can burn you.
- 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 .
'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
¢ ,&. .
A WARNING
To help avoid injury, before you check any­
thing under the hood:
- Turn off the engine.
- Switch off the ignition .
- Apply the parking brake.
- Move selector lever to "P" (Park) .
- Always let the engine cool down. Hot
components will burn skin on contact.
- 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.
- Keep children away from the engine com­
partment.
- Never spill fluids on hot engine compo­
nents . They can cause a fire .
- Never touch the radiator fan. The auxili­
ary electric fan is temperature controlled
and can switch on suddenly .
- Never open the coolant reservoir cap
when the engine is still warm . The cool­
ant system is pressurized and hot cool­
ant could spray out.
- Protect your face, hands and arm from
steam or hot engine coolant by placing a
thick rag over the cap when you open the
coolant reservoir.
- Do not
remove the engine cover under
any circumstances. This increases the
risk of burns.
- If work on the fuel system or the electri­
cal system is necessary:

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Checking the engine coolant level
The engine coolant level can be checked with
a quick glance .
Fig. 204 Eng ine compartme nt: cover o n the coolant
expansion tank
Before you check anything in the engine com­
partment,
a lway s read and he ed all WARN ­
INGS ¢ & in Working in the engine compart­
ment on page 228.
Park your vehicle on a level surface.
~ Switch off the ignition.
~ Read the engine coolant leve l from the cool­
ant expansion tank¢
fig. 204, ¢ page 230.
With a cold engine, the coolant level should
be between the "min" and "max" markings.
When the engine is warm, the level may be sl ightly above the ''max" marking.
The location of the coolant expansion tank
can be seen in the engine compartment illus­
tration ¢
page 230 .
To obtain an accurate reading, the engine
must be switched off.
The expansio n tank in your vehicle is equipped
with an electric coolant level sensor.
When t he coo lant level is too low, the warning
light in the Auto-Check System¢
page 15 will
illuminate unti l yo u add coolant and the level
has been restored to normal. Even thoug h
there is an electric coolant level sensor, we
still recommend you check the coolant level
from time to time.
Coolant loss
Coolant loss may indicate a leak in the cooling
system. In the event of coolant loss, the cool-
Checkin g and fillin g 237
ing system shou ld be inspected immediately
by your authorized Audi dealer . It is not
eno ugh merely to add coo lant .
In a
s ealed system, losses can occu r on ly if
the boiling point of the coo lant is exceeded as
a resu lt of overheating.
A WARNING
The cooling system is under pressure and
can get very hot. Red uce the risk of scald­
ing from hot coolant by follow ing these
steps.
- Turn off the engine and allow it to cool
down.
- Protect your face, hands and arms from
escaping flu id a nd steam by cover ing the
cap with a la rge, th ick rag.
- Turn the cap slowly and very carefully in
a counter-clockwise d irect ion while ap­
p lyi ng lig ht, dow nward pressure on the
top of the cap.
- To avo id being burned, do not sp ill anti­
freeze o r coolan t on the exhaust system
or ho t engine parts. Und er certa in cond i­
tions, the ethylene gly co l in engine coo l­
an t can catch fire.
(D Note
Do not add any type of radiator leak sea l­
ant to your veh icle's engine coo lant. Add­
i ng radia to r repa ir flui d may adverse ly af­
fe ct the fun ct io n and perfor man ce o f you r
coo ling system and could result in damage
not cove red by your New Vehicle Limi ted
War ranty.
Adding coolant
Be very careful when adding engine coolant .
Before you che ck a nyt hing in the eng ine com­
partmen t,
alway s re ad and he ed alt WARN­
INGS ¢ & in Working in the engine compart­
ment on page 228.
~ Requirement: There must be a residua l
a mo unt of coolan t in the expansion ta nk
¢(D.
~Tu rnoff the engine . •
•

238 Check ing and filling
• Let the engine coo l down .
• Place a thick rag over the coolant expansion
tank
¢ page 237, fig . 204 and care full y
twist the cap counter-clockwise¢ _&..
• Add coolant mixed in the correct ratio
¢
page 236, Coolant up to the MAX mark­
i ng.
• Make sure that the fluid level rema ins sta-
ble. Add more coolant if necessary.
• Twist the cap on again
tightly.
Replacement engine coolant must conform to
exact specifications ¢
page 236, Coolant.
We recommend using only coolant additive
G12++, G13 or in an emergency G12+ . Do not
use a different additive . In an emergency use
p la in water unt il you can get the correct add i­
tive and can restore the correct ratio. This
should be done as soon as possible .
If you have lost a considerable amount of
coolant, then you should add co ld antifreeze
and cold water only when the engine is co ld.
Always use
new eng ine coolant when refilling .
Do not fi ll coolant above the "MAX" mark. Ex­
cess coolant will be forced out through the pressure relief valve in the cap when the en­
g ine becomes hot .
A WARNING
- T he coo ling system is under p ressure and
can get very hot. Reduce the risk of
scalding from ho t coolant by following
these steps.
-Turn off the eng ine and a llow it to cool
down.
- Protect your face, hands and arms from escaping flu id and steam by cover ing
the cap with a large, thick rag.
- T urn the cap slowly and very carefully
in a counter-clockwise d irect ion while
apply ing light, downward pressure 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 certa in cond
it ions, the ethylene g lycol in en­
gine coolant can catch fire.
- Antifreeze is poisonous . A lways store an­
tifreeze in its origina l container and well
out of the reach of children.
- If you dra in the coo lant, it must be
caught and safely stored in a proper con­
tainer clearly marked "po ison".
@ Note
- Do not add coolant if the expansion tank
is empty. Air co uld enter the cooling sys­
tem and damage the engine. If this is
the case, do not cont inue driving. Seek
professional assistance .
- Coo lant pollutes the environment and
cou ld cause an engine f ire. Excess cool­
ant will be forced out through 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 co rrect ratio between water
and antifreeze ¢
page 236 must be re­
stored as soon as possible.
@ For the sake of the environment
D rained coolant should not be reused . Al­
ways d ispose of used coolant while observ­
i ng all envi ro nmental regula tions.
Radiator fan
The radiator fan switches on automatically by
itself
The rad iator fan is driven by the e ngine via the
V-belt. The viscous clutch regulates the speed of the fan acco rding to the temperatu re of the
coolant.
An auxiliary electric radiato r fan* sw itches on
and off depending on coolant temperature
and ot her vehicle ope rat ing condit io ns.
After you switch the eng ine off, the aux iliary
fan can continue running for up to 10 m inutes
- even w ith the ignition off .
It can even switch
o n aga in later by itself¢.& , if
1111>

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Settings ... .. ........... .. .. .. .... 34
Unlocking and locking vehicle ... .. .. .. 35
Pow er seat adjustment
Front seats . . . . . . . . . . . . . . . . . . . . . . . . S9
Rear seats . . . . . . . . . . . . . . . . . . . . . . . . . 61
Power steering
refer to Electromechanical power assist 201
Power windows ............ .... .. .... 41
malfunction ............. .... .. .. .. 42
Pregnant women
Special considerations when wearing a
safety belt . . . . . . . . . . . . . . . . . . . . . . . 148
pre sense .. .. .. ........... .. .. .. .. . 194
Preventative passenger protection . . . . . 194
Programming the Hom elink universa l re-
mote control ................. ... ... 131
Proper occupant seating positions .. .. . 134
Proper safety belt position ... .. .. .. .. . 147
Proper seating position
Front passenger ................... 135
Occupants .. ................. .. ... 134
Rear passengers .......... .. .. .. ... 136
Protecting 216
Q
quattro
refer to All Wheel Drive ............. 202
Question What happens to unbelted occupants? 144
Why safety belts? ............... .. 143
R
Radiator fan ... ........... .. .. .. ... 238
Radio clock .. .. .............. ... .... 27
Rain/light sensor Headlights .............. .... .. .... 46
I ntermittent (windshield wipers) . . . . . . 53
Sensor defective . . . . . . . . . . . . . . . . . . . . 22
RangeffuelleveO .................... 25
Reading lights . ............... ... .... 50
Rear fog lights ............ .... .. .. .. 46
Rear lid
Escape handle
Rear light 266
Defective .. ............. .... .. .... 22
Index 303
Rear seats
Adjusting individual seats ......... .. . 61
Entry assistance . ... .............. .. 64
Front passenger seat adjustment . . . . . . 64
Reclining rear seat .................. 63
Rear view mirror ... .. .............. .. 56
Rear window heating . ................ 80
Recircu lation mode (automatic climate
control) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Reclining rear seat ... .............. .. 63
Recuperat ion .. .. .. .. . .. ... .... .... .. 25
Refuelling ... ... .. .. ............... 223
Remote control Garage door opener (HomeLink) ...... 131
Massage function . . . . . . . . . . . . . . . . . . . 64
Unlock ing and locking .............. . 35
Remote luggage compartment lid release 37
Repair manuals .. ................... 290
Repairs Airbag system ..... .............. . 164
Replacing Fuses ......... .. ................. 276
Light bulbs .. .. .. .... ........... .. 280
Tires and wheels ... .............. . 257
Windshield wiper blades ............ . 54
Reporting Safety Defects ............. 141
Request to warm engine by driving Warning/indicator lights ........ .. .. . 21
Reset button . . . . . . . . . . . . . . . . . . . . . . . . 26
Retractor . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Rims Cl eaning ...... .... ............... 215
Roof rack . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Loading ........................... 73
Roof weight . .. .. .... ........... .. . 73
s
SAFE ................... ........... 26
Safe driving habits ... .............. . 133
Safety belt pos ition . . . . . . . . . . . . . . . . . 14 7
Safety belts worn by pregnant women . 148
Safety belt pretensioner . . . . . . . . . . . . . . 149
Serv ice and disposal ... ... .... ..... 150
Safety belt pretensioners Pre sense . . . . . . . . . . . . . . . . . . . . . . . . 194
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