2016 AUDI A4 check engine light

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Tire pressure
When tow ing a tra ile r, infl ate the tires of yo ur
ve hicl e to the co ld tire press ure listed under "Fu ll
l oad" on the label located on the driver's side B­
pi llar (visib le when th e door is open). Inflate
tra ile r tir es to t railer and tire manufacture rs'
specifications.
Light s
The headlight settings should be checked wi th
the trai ler attached before driv ing
off . Check to
make sure both veh icle and trai ler lights are
wo rking prope rly .
Safety chains
Be s ure trai ler s afety chains are p ro p erly conne ct­
ed from the trailer to the hitc h on the vehicle .
L eave enough slack in the chains to permit turn­
ing corners . When you install safety cha ins, make
sure they w ill not drag on the road when yo u are
driving.
The chains s hou ld cross under the t railer tongue
to p revent it from dropp ing in case of separat ion
from t he hitc h.
Driving instructions
Driving with a trailer always requires extra core
and consideration.
To ob tain the best possible handling of vehicle
and trailer, please note the fo llowing :
.,. Do no t tow a lo ad ed t railer w hen yo ur car i tse lf
i s not lo ad ed.
.,. Be especia lly caref ul when passing ot he r
vehicles .
.,. Observe speed limits.
.,. Do not d rive at the maximum permissible
speed .
.,. Always apply brakes early .
.,. Moni to r th e temperature gauge .
Weight distribution
T owing a loaded trailer w ith an empty car res ults
in a high ly unstable distribution of weight . If this
cannot be avo ided, drive at very low speeds o nly
to avoid the risk of losing steering control.
Trailer mode
A "ba lanced" rig is easier to opera te and co ntrol.
This means that the tow vehicle sho uld be loaded
to the extent possib le and permissib le, w hile
keeping the trailer as light as possible under the
cir cumstances . Wheneve r poss ib le, transfer
some cargo to the luggage compartment of the
tow ve hicle while observing tongue load require­
ments and vehicle loa ding consi de rations .
Speed
The higher the speed, the mo re diff icult it be­
comes for the driver to control the r ig. Do not
drive at t he max imum permissib le speed. Reduce
you r sp eed even more if load, weathe r or wind
cond it ions are u nfavo rab le -pa rticularly when
go ing down hill.
Reduce vehicle speed
immediately if the trailer
shows the slightes t sign of sway ing .
Do not try
to stop the swaying by accelerating .
Observe speed limits . In some a reas, speeds fo r
vehicles towing trailers are lower tha n for regular
vehicles .
Always apply bra kes early . When d riving down­
hill, shift into a lower gear to use the e ngine
braki ng effect to slow the vehicle . Use of the
brakes alone can cause them to overhea t and fa il.
Coolant temperature
The coo lant tempe rature gauge c:> page 10 m ust
be obse rved caref ully. If the needle moves close
to the upper end of the scale, reduce speed im­
me diate ly and/or t urn
off th e a ir cond it io ne r .
If the coolant temperat ure warning light . in
t h e instr ument cluster starts flashing, pull
off
the road, stop and let the engine idle for about
two m inu tes to pre vent heat build -u p .
A WARNING ,.__ -
A nyone not prope rly restr ained in a moving
ve hicl e is at a m uch grea te r risk in an a cci ­
d ent. Never le t anyon e ride in your car w ho is
n o t pr ope rly we arin g th e res tra ints p ro vid ed
by Au di .
191

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Checking and Filling Hood
Releasing and opening the engine hood
The engine hood is released from inside the vehi­
cle.
Fig. 179 Driver's side footwell: engine hood re lease lever
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Fig. 1 80 Release lever under the engine hood
Before opening the engine hood, make sure that
the windshield wipers are flat against the w ind­
shie ld. Otherwise, they could damage the paint
on the hood.
.. Wi th the driver's door open, pu ll the leve r un­
der the instrument panel in the direction of the
arrow ¢
fig. 179 .
.. Raise the hood slightly¢&.
.. Press the rocker switch under the hood upward
¢fig . 180. This releases the catch.
.. Open the hood.
A WARNING
Hot engine coo lant can burn you.
- To reduce the risk of be ing burned, never
open t he hood if yo u see or hear steam or
coolant esca ping from the eng ine compart­
me nt. Wait unt il no s team or coolant ca n be
Checking and Filling
seen or hea rd before carefully opening the
hood.
Closing the engine hood
.. Pull the hood down until the pressure from the
struts is reduced.
"' Le t the hood
drop down and latch in p lace. Do
not try to push it shut;
it may fail to engage
¢ &, .
A WARNING
A hood that i s not comple tely latched co uld
fly up a nd blo ck your view while driv ing.
- W hen you close the engine hood, check it to
ma ke sure the s afety catch h as prope rly en­
ga ged. The hood should be flush with t he
surroundi ng ve hicl e body pa rts.
- If you no tic e while driv ing t hat t he hoo d is
not secured properly, stop at once and close
it.
Working in the engine compartment
Be e specially careful whenever you work in the
engine compartment.
-
Whenever you mu st perform an y work in the
engine compartment, for example checking and
filling different fluids, there is a risk of injury, burn s and a ccidents. To prevent per sonal injury
always observe the following WARNINGS. The
eng ine compa rtment of any vehicle is a hazard ­
ous area
¢ .&. .
A WARNING
-~
To help avoid injury, before you check any­
th ing under the hood:
- Turn off the engine.
- Remove the ignition key .
- Apply the par king brake.
- Move selector leve r of autom atic t ransm is-
sion to "P" (Park); put manual transm ission
in Neutral.
- Always let the engine cool down. Ho t com ­
ponents w ill bur n skin on contact .
203

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Checking and Filling
Engine compartment
Engine compartment
These are the most important items that you can check.
Fig. 181 Typical layout for containers and e ngin e oil fille r cap
(D Eng ine o il filler cap ( @ Jump start po int(+) under a cover
@ Brake fluid reservoir
((0) ...... .
@ Coolant expansion tank (- L) .... .
® Jump start point( -) with hex head 207
214,251
211 210
screw . . . . . . . . . . . . . . . . . . . . . . . 214, 251
@ Windshield/headlight* washer con-
tainer
(W) . . . . . . . . . . . . . . . . . . . 216
The position of the engine oil filling hole
c:> fig. 181 (item @) can differ depending on the
engine design .
A WARNING
Before you check anything in the engine com­
partment, always read and heed all WARN­
INGS
c:> &. in Working in the engine compart­
ment on page 203.
Engine oil
Engine oil specifications
The engine oil used must conform to exact speci­
fications.
The service interval display in the instrument
cluster of your vehicle will inform you when it is
time for an oi l change . We recommend that you
have your oi l changed by an authorized Audi Serv­
ice Advisor.
If you have to top off the oil between oil changes,
use the Audi oil quality standard specified in the
table .
Audi oil quality standard
Gasoline
VW 502 00 or
engine vw 504 00
205

Check ing and F illing
Using the proper engine oil is impo rtant for the
functionality and service life of the engine. Your engine was facto ry-filled with a h igh-quality oi l
which can usually be used throughout the entire
year.
@) Note
Your Limited New Vehicle War ranty does not
cover damage or malfunctions due to failure
to follow recommended maintenance and use
requirements as set forth in the Audi Owner's
Manual and Warran ty
& Maintenance booklet.
- Use only a high quality eng ine oil t hat ex-
p ressly complies with the Audi oil qua lity
standard specified for your vehicle's engine .
Using a ny o ther oil can cause serious engine
d am age.
- D o not mix any lubricants o r other addit ives
i nto the engine oil. Doing so ca n cause en­
g ine damage.
(D Tips
I f you need to add oil and there is none availa­
ble t hat meets the Audi o il quality standard
your eng ine requi res , you m ay ad d a tot al of
no more than 0.5 qu art /li ter o f a h igh-quality
"synthe tic"oil that meets t he following speci ­
fications.
- Vehicles w it h gasoline eng ine: AC EA A3 o r
API SM with a viscosity grade of SAE 0W-30,
SAE SW -30 or SAE SW-40.
- Fo r more information about en gine o il that
has been approve d for your ve hicle, please
contact eithe r you r a uthorized Aud i dea ler
or A udi C ustome r Relat ions at
1 (800) 822-2834 or visit our web site at
www .audiusa .com or www.aud icanada .ca .
Engine oil consumption
The engine in your vehicle depends on an ade­
quate amoun t of oil to lubricate and cool all of
its moving parts .
In order to provide effective lubr ication and coo l­
ing of in ternal engine components, all internal
combustion eng ines consume a certain amou nt
of oil. Oil co nsumption varies from engine to en­
g ine and may change significant ly over the life of
206
th e engine. Typically, engines w ith a specified
break-in period (see
r=:> poge 185) consume more
o il dur ing the b reak-in per iod than they consume
after oil consumption has stabili zed .
U nder normal cond itions, the rate of oil con ­
sumption depends on the q ua lity and viscosity of
the oil, the RPM (revo lutions per m inute) at
which the engine is operated, the ambient tem­ perature and road condit ions. Further factors are
the amo unt of o il di lution from water condensa ­
t ion or fuel residue a nd the oxidation level of the
o il. As any engine is subject to wea r as mileage
builds up, the o il cons umption may increase ove r
t i me unt il repla ce m ent of wo rn components m ay
be come necessary .
With a ll these va riab les coming into p lay, no
sta ndard rate of o il cons umption can be estab­
li sh ed or spec ified . T he re is no alte rn ative to reg­
ul ar and frequen t checking of the oi l level, see
Note .
If the yellow engine oi l leve l wa rning symbo l Ill
in the instrument clus ter lights up , you sho uld
c h eck t he o il level as soon as possible
r=:> page 207 . Top off the oi l at your ea rliest con­
venience
r=:> poge 207.
A WARNING
Before you check anyth ing in the engine com­
partment, always read and heed all WARN­
INGS
r=:> .&. in Working in the engine compart­
ment on page 203 .
@ Note
Driving wit h an insuffic ient oil level is like ly to
cause severe damage to the eng ine.
(D Tips
- The oil pressure warning display. is not
an indicator of the oil level. Do not rely on
it . Instead, check the oil level in your en­
gine at regular intervals, preferably each
time you refuel, and always before going
on a long trip .
-If you have the impress io n your e ngine con­
sumes excessive amou nts of oil, we recom-
mend th at yo u consult an authori zed A udi .,.

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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
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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. ""
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