2016 AUDI A4 check engine

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dealer to have the cause of your concern
properly diagnosed. Keep in mind that the
accurate measurement of oil consumption
requires great care and may take some
time. An authorized Audi dealer has instruc­
t ions about how to measure oil consump­
tion acc urately.
Checking the engine oil level
Fig. 1 82 MMI D is pl ay: O il leve l indicator
Read o il level
• Park yo ur vehicle so that it is horizonta lly level.
• Shut the engine off when it is at operat ing tem -
perature .
• Switch only the ignition back on.
• Wait approx . two minutes .
• Se lect: Funct ion button
~ IC ~A ~R~ I > Oil level. Or
• Se lect: Funct ion but ton
ICARI > Car systems *
contro l butto n > Servicing & che cks > Oil leve l.
• Read the o il level in the MMI* Disp lay
r:::> fig. 182. Add engine o il if the bar o f the oil
level indicator is nea r "m in"
r:::> page 207
Depending on t he way the ve hicl e is driven a nd
the operati ng cond itions, o il cons umption can be
up to a 1/2 quart per 600 mi les (0 .5 liter per
1,000 km). Cons umption may be highe r within
the first 3,000 miles (5,000 km).
@ Tips
T he oi l level indicator in the M MI* Disp lay is
only an information d isp lay . If the oil leve l is
too low, a minimum o il warning appears in
the instrument cluster . Add oi l
r=>page 207.
If the hood has been opened, the current oil
level is shown i n the instrument cluster the
next time the ignition is sw itc hed on.
Checking and Filling
~ Adding engine oil
Fi g. 18 3 En g in e compa rtment: Cover o n the o il filler neck
• Before you check anything in the engine com­
pa rtment,
always read and heed all WARN­
INGS
¢ .&. in Working in the engine compart­
ment on page 203.
• Shu t the eng ine off.
• Uns crew the cap
'e::1': to the engine oil f illing
hole
r:::> fig. 183, ¢page 205, fig . 181.
• Carefully top off with 0 .5 quarts (0 .5 liters) of
the approp riate oil¢
page 205.
• Check the oil level again after two minutes
r=> page 20 7, Checking the engine oil level.
• Top off the o il agai n, if necessary.
• Screw the cap back on the fil ling ho le.
A WARNING
-
- Wh ile topping off, the o il must not com e in
con tact w ith ho t engine parts - fi re hazard!
- The o il filler cap must be p roperly secured
to p reve nt o il from being sprayed on the h ot
engine and exha ust system whe n the e ng in e
is ru nning - fire haz ard!
- I f you r skin has come in cont act wi th the en­
g ine oil, yo u m ust s ubsequently cleanse i t
thoroug hly.
CJ) Note
- Check the oil level using the ra dio or MMI*.
If the message
Please reduce oil level ap­
pea rs, con tact your authori zed A udi dealer
or qualifie d workshop to have excess oi l ex­
tracted if necessary.
- Audi does not recommend the u se of oil
additives . They may damage the engine
and adve rsely affect your New Vehicle
Warranty.
207

Check ing and F illing
@ For the sake of the environment
- Under no circumstances can the oil come in
contact with the sewage network or the soil.
- Observe and fo llow legal regulations when
disposing of empty oil containers .
Changing the engine oil
We recommend that hove your oil changed by on
authorized Audi dealer or a qualified service sta­
tion .
Before you che ck anything in the eng ine compart ­
ment,
always read and heed all WARNINGS ¢ A
in Working in the engine comportment on
page 203.
The engine oil must be changed according to the i n tervals specified in your Warranty
& Mainte­
nance booklet . This is very important because the
lubricat ing propert ies of oil diminish gradually
during normal vehicle use.
Under some circ umstances the eng ine oi l sho uld
be changed more frequently. Change oil more of­
ten if yo u drive most ly short distances, operate
the vehicle in dusty areas or under predominantly
stop-and-go traffic cond it ions , or have your vehi­
cle where temperatures remain below freezing
for extended periods .
Detergent additives in the oil will make fresh oil
look dark after t he engine has been run ning for a
short t ime . T his is normal and is not a reason to
cha nge the oil mo re often than recommended .
Because of the prob lem of proper disposal, along
with the special tools and necessary expertise re­
qu ired, we strongly recommend that you have
your oil c hanged by an aut ho rized
Audi dealer o r
a qualif ied se rvice station .
If you choose to change your o il yourself , please
note the following important informat ion:
A WARNING
To re duce the risk of pe rsonal injury if you
must c hange t he engine oil in your ve hicle
yo urs elf:
- W ear eye protection .
208
-
-To reduce the r is k of burns from hot engine
oil, let the engine cool down to the touch .
- W hen removing the oil drain plug with your
fingers, stay as far away as possible. Always
keep your forearm pa rallel to the ground to
he lp prevent hot oil from run ning down your
arm .
- Drain t he oil into a container designed for
this purpose, one large enough to hold at
leas t the tota l amou nt of oil in you r engine.
- Engi ne oil is poisonous . Keep it well out of
the reach of childre n.
- Continuous contact wit h used engine o il is
ha rmf ul to your skin. Always protect your
skin by washi ng oil
off thoroughly with soap
and wate r.
(D Note
Neve r mix oil additives with yo ur engine oil.
These additives can damage your e ngine and
adverse ly affect your A udi L imi ted New Vehi ­
cle Warranty .
@ For the sake of the environment
-Be fore chang ing you r oi l, first make sure
you know where you can properly dispose o f
t h e used oil.
- Always dispose of used e ngine o il pro perly .
Do not d ump it on garden so il, wooded
areas, into op en streams o r down sewage
drains.
- Recycle used e ngine o il by tak ing it to a used
eng ine oil collect io n fa cil ity in you r area, o r
c o nta ct a servi ce st ation .
Cooling system
Coolant '
The engine coolant performs two functions: it
keeps the engine from overheating and it pro ­
tects the engine from free zing in the winter.
The coolin g system is sealed and generally re­
quires little attention .
The coo lin g sys tem h as been filled a t the fac to ry
wi th a pe rmanent coolan t which does not need to
be changed. The coo lant consists of a mixture of .,.

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er's g lycol-bas edcoo lant additive Gl3 antifreeze
with anticorrosion additives (50% for USA mod­
e ls; 60% for Canadian models). This m ixture
both assures the necessary frost protection and
protects metal components in the engine's cool­
ing system from corrosion and scaling.
It also
raises the boiling point of the coolant .
Do not reduce the concentration of the coolant in
the summer by adding p lain water .
The propor­
tion of coolant addit ive must be at l eas t 50° /4
but not more th an 60 %
to maintain antifreeze
p rotection and cooling effic iency. If the coolant
frost protec tion is too low, the coolant co uld
freeze and damage the vehicle heating and en­
gine cooling system.
F or yea r-round driving, antifreeze is added at the
factory for temperatures down to :
- -31 °F (- 35 °C) USA
- -40 °F ( - 40 °C) Canada.
If you must add coolant, use a mixture of water
and coolant addit ive. Mixing the coolant additive
with d istilled water is recommended.
A WARNING
Before you check anything in the engine com­
partment, always read and heed all WARN ­
INGS
Q &. in Working in the engine compart­
ment on page 203.
(D Note
- Before winter sets in, have the coolant
checked to see if the coolant additive in your
vehicle is sufficient to meet the climate con­
dit ions. This is especially important if you
li ve in a reg ion where the w inte r is ext reme­
l y co ld. If ne cessary, in cre ase the proport io n
of coo lant add itive to 60%.
- When addi ng coolant addit ive to you r cool­
i ng system, remember:
- We recommend using only coolant addi­
tive Gl2 ++ or Gl3 for your ve hicle. T his
coolant additive is available at authorized
Audi dea lers. Othe r types of antifreeze can
significant ly reduce cor ros ion p rotection .
Ch eck ing and Filling
The resulting co rrosion can cause a loss of
coolant and serious engine damage.
- Do not add any type of radiator lea k sealant
to your vehicle's engine coolant. Adding ra­
diator repair fluid may adversely affect the
function and performance of your cooling
system and cou ld resu lt in damage not cov­
ered by your New Veh icle Limited Warranty.
Checking the engine coolant level
The engine coolant level can be checked with a
quick glance.
F ig. 184 En gin e co mpa rt men t: Cover o n the coo la nt ex ­
pans ion t ank
.. Before you check anything in the eng ine com ­
partment,
al ways read and heed all WARN ­
INGS
q ..&. in Working in the engine compart­
ment on page 203 .
.. Park your ve hicle on a leve l sur face .
.. Tu rn off the ignit io n .
.. Read the eng ine coolan t level from the coo lant
expansion tank
q fig . 184, Q page 205,
fig. 181 .
With a cold engine, the coolant level
should be between the " MIN" and "MAX" mark­
ings. When the engine is warm, the level may
be slightly above the "MAX" marking.
The location of the coo lant expansion tank can be
seen in the engine compartment illustration
q page 205.
To obtain an accurate reading, the engine must
be switched off.
T he expansion ta nk in your veh icle is eq uipped
with an electric coo lant level senso r.
When the coolant leve l is too low , the warning
light i n the Auto-Check System
Q page 17 will
209

Check ing and F illing
blink until you add coolant and the level has been
restored to normal. Even though there is an e lec ­
tr ic coolant level sensor, we still recommend you
check the coo lant level from time to time.
Coolant los s
Coolant loss may indicate a l e ak in the cooling
system. In the event of coolant loss, the cooling
syst em should be insp ected immediately by your
authorized Audi dealer. It is not enough merely
to add coolant.
I n a
s e aled system, losses can occur only if the
boiling point of the coo lant is exceeded as a re­
sult of overheating.
A WARNING
The cooling system is under pressure and can get very hot. Reduce the risk of scalding from
hot coolant by following these steps.
- Turn off the eng ine and allow it to cool
down .
- Protect your face, hands and arms from es­
caping fluid and steam by covering the cap
with a large, thick rag.
- Turn the cap slowly and very carefully in a
counter-clockwise direction wh ile apply ing
l ight, 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 eng ine parts . Under certain conditions,
the ethy lene g lycol i n engine coolant can
catch fire.
{Q) Note
Do not add any type of radiator leak seala nt
to your veh icle's engine coolant . Adding radia­
to r repa ir fluid may adversely affec t the func­
tion and performance of yo ur cooling system
and could result in damage not covered by
your New Vehicle Limited Warranty.
Adding coolant
Be very careful when adding engine coolant.
Before you check anyth ing in the eng ine compart­
ment,
a lwa ys re ad an d heed all WARNINGS
210
¢ A in Working in the engine compartment on
page 203.
Requireme nt: The re must be a res idual amount
of coo lant in the expans ion tank
~CD-
.,,. Turn off the engine .
.,,. Let the engine cool down.
.,,. Place a thick rag over the coolan t expa nsion
tank ¢ page 209, fig. 184 and
carefull y turn
the cap counter-clockwise ¢.&_ .
.,,. Add coo lant mixed in the correct ratio
~ page 208, Coolant up to the MAX marking.
.,,. Make sure that the fluid level remains stab le.
Add more coolant if necessary .
.,,. Twist the cap on aga in tightly.
Replacement engine coolant must conform to ex­
act specifications ¢ page 208, Coolan t.
We recommend using only coo lant additive
G l2 +
+ , Gl3
or in an emergency Gl2+. Do not use a
different additive . In an emergency use plain wa ­
ter unt il you can get the correct addit ive and can
restore the correct rat io. Th is should be done as
soon as possible.
If you have lost a considerable amount of cool­
ant, then you should add cold antifreeze and cold
water only when the engine is cold.
Always use new engine coo lant when refilling .
Do not fi ll coolant above the "MAX " mark. Excess
coolant will be forced out th rough the pressure
relief valve in the cap when the engine becomes
hot.
A WARNING
- The cooling system is under pressure and can get very hot. Reduce the risk of scalding
from hot coolant by following these steps.
- Turn off the engine and a llow it to cool
down.
- Protect your face, hands and arms from
escaping fluid and steam by covering the
cap with a large, thick rag.
- Turn the cap s low ly and very ca refully in a
counter-clo ckwise direction wh ile app ly ing
li ght, downward pressure on the top o f
the cap.
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-To avoid being burned, do not spill anti­
freeze or coolant on the exhaust system or hot engine parts. Under certain condi­
tions, the ethylene glycol in engine cool­ ant can catch fire.
- Antifreeze is poisonous. Always store anti­
freeze in its original container and well out
of the reach of children.
- If you drain the coolant, it must be caught
and safely stored in a proper container
clearly marked "poison".
(D Note
-Do not add coolant if the expansion tank is
empty . Air could enter the cooling system
and damage the engine. If this is the case,
do not continue driving. Seek professional
assistance.
- Coolant pollutes the environment and could
cause an engine fire. Excess coolant will be
forced out through the pressure relief valve
in the cap when the engine becomes hot.
- If, in an emergency, only water can be add­
ed, the correct ratio between water and an­
tifreeze
c::> page 208 must be restored as
soon as possible.
@) For the sake of the environment
Drained coolant should not be reused. Always
dispose of used coolant while observing all
environmental regulations.
Radiator fan
The radiator fan switches on automatically by it­
self.
The radiator fan is driven by the engine via the V­
belt . The viscous clutch regulates the speed of
the fan according to the temperature of the cool­
ant.
An auxiliary electric radiator fan* switches on and
off depending on coolant temperature and other
vehicle operating conditions.
After you switch the engine off, the auxiliary fan
can continue running for up to 10 minutes -even
Checking and Filling
with the ignition off. It can even switch on again
later by itself
c::> & , if
- the temperature of the engine coolant rises due
to the heat build-up from the engine in the en­
gine compartment, or
- the engine compartment heats up because the
vehicle is parked in intense sunlight.
A WARNING
-To reduce the risk of personal injury never
touch the radiator fan.
- The auxiliary electric fan is temperature
controlled and can switch on suddenly even
when the engine is not running.
- The auxiliary radiator fan switches on auto­
matically when the engine coolant reaches a
certain temperature and will continue to run
until the coolant temperature drops.
Brake fluid
Checking brake fluid level
The broke fluid level con be checked with o quick
glance .
Fig. 185 En gi ne compartmen t: Cover on the b rake fl uid
reservoir
Before you check anything in the engine compart ­
ment,
always read and heed all WARNINGS
c::> _.& in Working in the engine comportment on
page 203.
.,. Read the brake fluid level from the brake fluid
reservoir
c::> fig. 185, c::> page 205, fig . 181 . The
brake fluid level must be between the "MIN"
and "MAX" markings.
211

Check ing and F illing
The brake fluid rese rvoir is located at the rear
partition of the engine compartment on the l eft
side ¢
page 205 .
The fl uid level may drop slightly after some time
due to the automatic adjustment of the brake
pads . This is not cause for alarm.
If th e b rake fl uid level fa lls considerably be low
the "M IN" mark, the b rake warning/ind icator
lig ht ( U.S. mode ls :
1111 , Canadian models:. )
will come on ¢
page 15. Do not contin ue to oper ­
ate the vehicle . T he comp lete brake system
should be thoroughly checked by an authori zed
Aud i dealer or qualified workshop and the cause
corrected . If the brake flu id level is too low, the
b rake warning/indicator light will i llum inate.
Contact a n author ized Audi dealer
immediately .
{D) Tips
The brake fluid reservoir is located under­
neath the cover .
Changing brake fluid
Have the brake fluid changed by an experienced
technician .
Brake fluid absorbs mo isture from the air. If the
water content in the b rake fluid is too high, cor­
rosion in the brake system may resu lt afte r ape ­
riod of t ime. The boiling poi nt of the brake flu id
will also decrease cons iderably and decrease
b raking perfo rman ce.
Therefore, the brake fluid must be changed
every
two year s.
Always use new brake fluid wh ic h con­
forms to Fede ral Motor Veh icle Standard "FMVSS
1 16 DO T 4".
The brake fluid reservoir can be diff icult to reach,
therefore, we recommend that yo u have the
brake fl uid changed by yo ur autho rized
Audi
dealer .
Your dealer has t he corre ct tools, t he
right brake fluid and the know-how to do this for
you.
A WARNING
- Brake fluid is poisonous. It must be stored
only in the closed orig inal container out of
the reach of chi ldren!
212
- Bra ke fa ilure ca n result from old or inapp ro­
priate brake fluid . Observe these precau­
tions:
- Use only brake fluid t hat meets SA E speci­
fi ca ti on
J 170 3 and con forms to Federa l
Motor Ve hicle Standard 116 . Always check
wi th yo ur autho rized Audi dea le r to make
s ur e yo u are using the correct brake fluid .
The correct type of brake flu id is also ind i­
cated on the b rake fluid reservo ir .
- The brake fluid m ust be new . Heavy use of
the brakes can cause a vapo r lock if the
brake fluid is left in the system too long .
This can se riously affect the efficiency of
the b rakes as well as your safety . This
could resu lt in an accident .
(D Note
Brake fluid will damage the paint of your veh i­
cle.
@ For the sake of the environment
Because of the problem o f proper d isposa l o f
brake fluid as well as the spec ial too ls re­
q ui red a nd the necessary expertise, we rec­
omme nd that you have the bra ke f luid
changed by yo ur autho rized Aud i dea le r.
Battery
, General information
U nder normal operating condit ions, the battery
i n your Audi does not need any maintenance.
With
high outside temperatures or long daily
drives we recommend that you have the elect ro ­
lyte level c hecked by an au thorized Aud i dealer o r
qualified workshop. The electro lyte level shou ld
a lso be che cked each time the battery is c ha rged
~ page 214.
Have the batte ry chec ked when you take yo ur ve­
hicle in for service. You are we ll adv ised to re­
pla ce a battery tha t is older than 5 yea rs.
With certain types of airbag deployment, t he
batte ry is d iscon nected from the ve hicle electri­
ca l system for safety reasons ¢.&.
in Repair, care
and disposal of the airbags on page 151. .,.

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0 ::..:: co ..... ..... Disconnecting the battery terminals
Some vehicle func tion s (p ower w indow reg ula­
tors, for example) are lost i f th e battery termi ­
na ls are d isconnected. These functions have to be
relearned afte r the battery termina ls are con­
nected aga in. To prevent th is, the batte ry shou ld
only be disconnected from the vehicle e lectr ica l
system w hen abso lute ly necessary for repairs.
Vehicles not driven for long periods
If yo u do not drive you r vehicle over a period of
seve ral days or weeks, e lectrical components a re
g radually c ut back or sw itched off. This reduces
e nergy consumption and ma inta ins starting ca ­
pability over a longer pe riod
c> page 182.
Some o f the conven ience f unctions may not ope r­
ate, s uch as the inte rior lights or the power seat
ad justment. The convenience functions will be
ava ila ble aga in whe n you tu rn o n the ignition and
start the engine .
Winter operation
During the winter months, battery capacity tends
to dec rease as temperatu res dr op. This is be­
cause more power is also consumed wh ile start ­
in g, and the head lights , rear wi ndow defogge r,
etc., are used more of ten .
Avoid un necessa ry power consumption, part icu­
l arly in city traffic or when t rave ling on ly short
d ista nces . Let your authorized Audi dealer check
the capaci ty of the vehicle battery be fore w inte r
sets in
r=;, pag e 214. A well cha rged batt ery w ill
n o t onl y preven t st arti ng p roble ms w hen the
wea ther is cold, but will also last l on ger .
(D Tips
If your v ehicle is left stand ing fo r se ve ral
wee ks at extre mely low tem per at ures, the ve­
hicle b attery sh ould be re moved and stor ed
w here it will not free ze . Th is will preve nt i t
from being dama ged and hav ing to be re ­
placed .
Checking and Filling
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. Befo re you check anything
i n the luggage compart ment ,
read and heed all
WARNINGS
c> &_ .
Always heed the safety warnings , when working
o n the veh icle batte ry or t he ve hicle elec trical
system to prevent in jury .
The following WARNINGS are very important
when working on the battery :
Always heed the following WARNING SYM-
BOLS and safety precautions when wo rking on
the battery.
®
Always wear eye protection.
A
Battery acid contains sulfuric acid. Al-
ways wear gloves and eye protection.
@
No
- sparks
- flames
- smoking.
~
When a battery is charged , it produces
hydrogen gas which is explosive and
could cause personal injury.
®
Always keep the battery well out of reach
of children.
A WARNING
= -
Whenever working on t he battery or on the
e lectr ica l system, the re is the r isk of injury,
accide nt a nd eve n fire. Read and he ed the fol­
l ow ing W AR NIN GS:
- Always wear eye protection. Do not let bat­
tery acid or any l ead particles ge t on you r
skin o r clothing. Shield yo ur eyes. E xplosiv e
g ases can ca use b lindne ss or other in jury.
- Ba tte ry acid contai ns sulfur ic acid. Sulfu ric
acid can ca use blindness and s evere burns.
- Always wea r gloves and eye protection . Do
n ot tilt t he batte ry because aci d could lea k
out of the ventilation openings. ""
213

Checking and Filling
-If you get batt ery acid in your eyes or on
your skin, immediately rinse with cold wa ­
ter for several minutes and get medical at­
tention .
- If you should ingest any battery acid, seek
medical attention immediately.
- Do not expose the battery to an open flame, electric sparks or an open light .
- Do not smoke.
- Do not interchange the positive and nega-
tive cables.
- When working on the battery, be sure not to short-circuit the terminals with tools or oth­
er metal objects. This would cause the bat ­
tery to heat up very quickly, which could lead to damage or explosion and personal
injury.
- When a battery is charged, it produces hy­
drogen gas which is explosive and could
cause personal injury.
- Always keep the battery well out of the
reach of children.
- Before work is done on the electrical sys­
tem, disconnect the nega tive ground cable .
- Before performing any work on the electri­ cal system, switch off the engine and igni­
tion as well as any electrical equipment. The negative cable on the battery must be dis­
connected. If you are just going to replace a
light bulb, then it is enough to switch off
the lights.
- Before disconnecting the battery, sw itch off
the anti-theft alarm system! Otherwise you
will set off the alarm.
- When disconnecting the battery, first dis­
connect the negative cable and then the
positive cable.
- Before reconnecting the battery, make sure
all electrical consumers are switched off.
Reconnect the positive cable first and then
the negative cable. Never interchange the
cabl es - this could start a fire!
- Never charge a frozen or a thawed-out bat­
tery . It could explode! If a battery has fro­
zen, then it must be replaced. A discharged
battery can freeze over at 32°F (0°C).
- Make sure the vent hose is always attached
to the opening on the side of the battery.
214
- Never use batteries which are damaged .
There is the danger of an explosion! Always
replace a damaged battery.
A WARNING
California Proposition 65 Warning:
- Battery posts, terminals and related acces­
sories contain lead and lead compounds,
chemicals known to the State of California
to cause cancer and reproductive problems.
Wash hands after handling .
(D Note
- Do not disconnect the vehicle battery when
the ignition is switched on or when the en­
gine is running, otherwise, you will damage
electronic components in the electrical sys­
tem .
-If your vehicle is going to stand for a long
period of time without being driven, protect
the battery from "freezing" , otherwise it
will be damaged and will then have to be re­
placed.
Battery charging
Starting the engine requires a well charged bat­ tery .
Fig. 186 En g in e compar tment : Co nnectors for charger and
jumper cab les
Always read and heed all WARNINGS below
9 A and ¢ A in Working on the battery on
page 213.
.,. Turn off the ignition and all electrical consum­
ers.
.,. Make sure the area is well ventilated when you
charge the battery.
Iii>-