2017 AUDI A4 check engine light

Trailer towing
Trailer towing
Driving with a trailer
General information
Your Audi was designed primarily for passenger
transportation.
If you plan to tow a trailer, please remember that
the additional load will affect durability, econo­my and performance.
Trailer towing not on ly places more stress on the
ve hicle, it also ca lls for more concentration from
the dr iver.
F or this reason, always follow the operating and
driving instructions provided and use common
sense.
Technical requirements
Trailer hitch
Use a weight-carrying hitch conforming to the
gross tra iler weight. The hitch must be suitab le
for your veh icle and tra iler and must be mounted
securely on the vehicle's chassis at a technically
sound
locat ion . Use on ly a trailer hitch with a re­
movable ba ll mount . Always che ck with the t rail ­
er hitch man ufac tur er to make s ure t hat you are
using the co rrect hi tc h.
Do not use a bumper hitch.
The hitch must be installed in such a way that it
does not interfere with the impact -absorbing
bumper system. No mod ificat ions should be
made to the vehicle exhaust and b rake systems .
Fr om t ime to t ime, che ck that all hitch mo unti ng
bol ts rem ain securely f aste ned.
W hen you are not tow ing a tra iler, remove the
tra ile r hitc h ba ll mount . This prevents the hit ch
from caus ing damage s hou ld your veh icle be
s truck from be hind ¢
,&..
Trailer brakes
If you r trailer is equipped with a brak ing system,
check to be su re that it conforms to all regula­
tions .
90
The t rai ler hydraulic bra ke system must not be
directly connected to the vehicle's hydraulic
bra ke system ¢&. .
Safety chains
Always use s afety chains be tween you r vehi cle
and t he tra ile r.
Trailer lights
Traile r lights must meet all regula tions . B e s ure
to check w ith your author ized Audi dealer for cor­
r ec t wir ing, swi tches and relays.
Mirrors
If you are unable to see t he traffic behind you us­
i ng t he regular outs ide mirrors, then yo u
must in­
stall ex tended mirrors . It is impo rtant that you
al ways have clear vision to the rear.
.&_ WARNING
Afte r remov ing the tra ile r hi tc h, do not s tore
it i n y our vehicle. In case o f su dden brak ing,
the hitch could fly fo rward and injure you or
your passengers.
Operating instructions
Maximum trailer weight
A tra iler f or yo ur vehicle is lim ite d to a typical
class 1 or class 2 trailer.
Trailer load distribution
Be sure the load in the t rai le r i s he ld se curely in
pla ce to p reve nt i t from shi fting forwar d, bac k­
ward or si deways.
Never allow a passenger to ride in a trailer ¢ &.
in Driver messages on page 91.
Engine cooling system
Towi ng a tra iler makes the engine work harder. It
is important that the cooling system's perform ­
ance is up to the additional load . Make sure tha t
the coo ling system has enoug h fluid.
Tire pressure
When towing a trailer, inflate the tires of your
vehicle to the cold tire p ressure listed under "Full
load" on the t ire press ure label. The t ire pressure
1111-

label is located on the driver's side B-pillar. In­
f late trai ler tires to trailer and tire manufactur­
ers' specifications.
Lights
The headlight settings should be checked with
the trailer attached before driving off. Check to
make sure both vehicle and trailer lights are
working properly.
Safety chains
Be sure trailer safety chains are properly connect­
ed from the tra iler to the hitch on the vehicle.
L eave enough slack in the chains to permit turn­
ing corners. When you install safety chains, make
sure they wi ll not drag on the road when you are
driving.
The chains shou ld cross under the trailer tongue
to prevent it from dropping in case of separation
from the hitch.
Driver messages
Driving with a trailer requires extra caution .
Weight distribution
Towing a loaded trailer w ith an empty car results
in a high ly unstable dist ribution of weight . If this
cannot be avo ided, drive at very low speeds only
to avoid the risk of losing steering control.
A "balanced" rig is easier to operate and cont rol.
This means that the tow vehicle should be loaded
to the extent possible and permissible, while
keeping th e trailer as light as possib le under the
circumstances . Whenever possib le, transfer
some cargo to the luggage compartment of the
tow vehicle whi le observing tong ue load require­
ments and vehicle loading considerations.
Speed
The higher the speed, the more difficult it be­
comes for the driver to contro l the rig. Do not
drive at the maximum permissible speed. Reduce
your speed even more if load, weather or wind
<( conditions are unfavorable -particularly when a,
;::; going downhill. ,....
N .... 0 0
3 a,
Trailer towing
Reduce vehicle speed immediately if the trailer
shows the slightest sign of swaying.
Do not try
to stop the swaying by accelerating.
Observe speed limits. In some areas, speeds for
vehicles towing trailers are lower than for regular
vehicles .
Always apply brakes early. When driving down­
hill, shift into a lower gear to use the eng ine
braking effect to slow the vehicle . Use of the
brakes alone can cause them to overheat and fail.
Coolant temperature
T he coolant temperature gauge~ page 11 must
be obse rved carefully. The coolant temperature
can increase if you drive on long inclines in a low
gear at high engine speeds . Reduce your speed
immediately if the LEDs in the top part of the dis­
play turn on.
For more information about indicator lights, re­
fer to.
~ page 31 .
A WARNING
= -
Anyone not properly restrained in a moving
vehicle is at a much greater risk in an acci­
dent. Never let anyone ride in your car who is
not properly wearing the restraints provided
by Aud i.
Trailer towing
information
Important to know
Your vehicle handles differently when towing a
trailer because of the addit ional weight and dif­
ferent weight distribution . Safety, performance
and economy will greatly depend on how careful­
ly you load your trailer and operate you r rig.
Before you actually tow your trailer, pract ice
turning, stopping and backing up in an area away
from traffic . Keep pract ic ing until you have be­
come complete ly familiar w ith the way your vehi­
cle-trailer combination behaves and responds.
91

Check ing and F illing
Checking and Filling
Gasoline
Fuel supply
Applies to: vehicles with gaso line engine
Using the right fuel helps keep the environment
clean and prevents engine damage.
F u el r eco mmend ati on
The fuel recommended for your vehicle is unle ad­
e d pr em ium
grade gasoline . Audi recommends
using TOP TIER Detergent Gasoline with a mini­
mum octane rating of 91 AKI (95 RON). For more
information on TOP TIER Detergent Gasoline,
p lease go to the offic ial website
(www.toptiergas .com).
The recommended gasoline octane rating for
your engine can also be found on a label located on the ins ide of the fuel filler flap . This rating
may be specified as AK I or RON .
Your veh icle may also be operated using unlead­
ed regular gasoline with a minimum octane rat ­
ing of 87 AKl/91 RON. However, using 87 AKI/91
RON octane fuel w il l slightly reduce engine pe r­
forma nce.
Us e un leade d gaso lin e onl y. Unleaded gasoline
is availab le throughout the USA , Canada, and in
most European countries . We recommend that
you do not ta ke your vehicle to areas or co unt ries
where un leaded gaso line may not be availab le.
For more information on refueling your vehicle,
see
¢ page 298 .
Octane rating
Octane rating indicates a gasoline's ability to re­
sist engine damaging "knock" caused by prema­
ture ignit ion and detonation . Therefore, buy ing
the correct grade of gasoline is very important to
he lp prevent poss ible engine damage and a loss
of eng ine performance.
Gasoline most commonly used in the Un ited
States and Canada has the following octane rat­
i n gs that ca n usually be found on the filler pump:
- Premium Grade: 91 - 96 AKI
296
- Regu la r Grade: 87 - 90 AK I
Explanation of the abbreviations:
AKI = Anti Knock Index = (R +M)/2 = (RON +MON)/
2
RON = Research Octane Number
MON = Motor Octane Number.
{[) Note
-Do not use a ny fue l w ith o ctane ratings low­
er than 87 AKI or 91 RON othe rw ise expen­
sive engine damage wi ll occur .
- Do
not use leaded gasoline. The use of lead­
ed gasoline will severely damage your vehi­
cle's catalyt ic converter and its ability to
control exhaust emissions .
Blended gasoline
Applies to: vehicles with gasoline engine
Use of gaso lin e conta ining alcoho l or MTBE
(meth yl tertia ry butyl ether )
You may use unleaded gasoline blended with al­
cohol or MTB E (commonly referred to as oxygen ­
ates) if the blended m ixture meets the follow ing
criteria:
Blend of g asoline methanol (wood alcohol o r
m eth yl alcoho l)
-Anti -knock index must be 87 AKI or h igher.
- Blend must contain no more than 3% metha-
nol.
- Blend must contain more than 2% co -solvents.
Blend of ga soline and ethanol (grain alcohol or
ethyl alc ohol )
- Anti-knock index must be 87 AKI or h igher .
- Blend must not conta in more than 15% etha-
nol.
Blend of gas oline and M TBE
- Anti-knock index must be 87 AK I or h igher .
- Blend must contain not mo re than 1S% MTB E.
S easonall y adjusted gasoline
Many gasoline grades are blended to perform es­
pecially well for winter or summer dr iv ing . Dur-
i ng seasonal change-over, we suggest that you .,..

Checking and Filling
the engine. See an authorized Audi dealer or
authorized Audi Service Facility for assis­
tance.
- Ad Blue attacks surfaces such as painted ve­
hicle components, plastic and carpet. Re­
move the fluid as quickly as possible with a
damp cloth and plenty of cold water. If the
Ad Blue has already crystallized, use warm
water and a sponge . Ad Blue residue that is
not removed will crystallize and can damage
the affected surface.
- Do not store refill bottles or canisters per­
manently in the vehicle. If the container
leaks, the escaping AdBlue could damage
the vehicle interior.
- Do not allow Ad Blue to come into contact
with clothing.
If there is contact with the
fluid , flush immediately with plenty of wa­
ter.
(D Tips
Follow the Ad Blue manufacturer 's instruc­
tions for use and storage.
Refilling AdBlue using the bottle
Applies to: veh icles with selective catalyt ic reduction
.. Remove the cap from the refill bottle¢ A in
Preparation on page 301,
~ CD in Preparation
on page 301.
.. Position the bottle on the filler tube and turn
the bottle clockwise until it stops turning.
.. Press lightly against the bottom of the bottle
to empty it. Continue pressing the bottom of
the bottle until it is empty or until fluid stops
flowing into the tank.
.,. Remove the bottle and seal the filler neck
¢ page 303, Completing AdBlue refill.
(D Note
Only use refill bottles that are approved for
your vehicle. Using other systems can cause
Ad Blue to leak.
(j) Tips
- You can obtain refill bottles from an author­
ized Audi dealer or authorized Audi Service
Facility.
302
- A permitted refill bottle contains approxi­
mately 0.5 gallon (1.9 liters) of AdBlue.
Refilling AdBlue using a canister
Applies to: vehicles with selective catalyt ic reduct ion
@
+®
Fig. 244 Canis te r w ith attachable hose
.,. Remove the cover from the refill canister ¢ A
in Preparation on page 301, ¢(Din Prepara­
tion on page 301 .
.. Secure the end of the hose (Don the opening in
the canister @by turning the hose to the right .
.. Remove the cap @from the other end of the
hose @ .
.. Position the end of the hose@on the filler
neck in the vehicle and turn the hose to the
right to tighten it .
.,. Lift the canister up and then tip it. Continue
holding the canister in a tipped position until it
is empty or until no more fluid flows into the
tank .
.. Remove the canister and close the filler tube
¢ page 303, Completing AdBlue refill .
([) Note
Only use refill canisters that are approved for
your vehicle. Using other systems can cause
AdBlue to leak.
(D Tips
- An authorized Audi dealer or authorized
Audi repair facility can tell you which refill
canisters are approved for your vehicle .
- A permitted refill canister contains approxi­
mately 1.3 gallons (5 liters) of Ad Blue.

reproductive harm. In addition, certain flu­
ids contained in vehicles and certain prod­
ucts of component wear contain or emit
chemicals known to the State of California
to cause cancer and birth defects or other
reproduct ive harm.
- Battery posts, terminals and related acces­
sories contain lead and lead compounds,
chem icals known to the State of California
to cause cance r and rep roductive harms.
Wash hands after handling.
(D Note
When filling flu ids, be sure not to mix the flu­
ids up . Otherwise severe ma lfunctions and en­
gine damage w ill occur.
@ For the sake of the environment
You should regularly check the grou nd under
your veh icle in order to detect Leaks qu ickly . If
there are v isible spots from oil or other fluids,
bring your vehicle to an authorized Aud i dea l­
er or authorized Audi Service Facility to be
checked.
Opening the hood
The hood is released from the interior.
F ig. 2 45 Dri ver fo otw ell : rele ase leve r
Checki ng an d Fill in g
Fig. 246 Unlocke d hood: lever
Make sure the wiper arms are not raised up from
the windshield. Otherwise the paint could be
damaged .
.,. With the driver's door open, pull the lever be­
low the instrument pane l in the direction of the
arrow
c;> fig. 245 .
.,. Raise the hood slightly c;> ,&. .
.,. Press the lever c;> fig. 246 in the direct ion of the
arrow. This releases the hooks .
.. Open the hood .
A WARNING
-
Never open the hood if you can see steam or
coolant escaping from the engine compart­ ment, because this increases the risk of
burns. Wait until no steam or coolant is es­
cap ing .
Closing the hood
.,. Push the hood down until you override the
force of the str uts .
.,. Let the hood fall lightly into the latch .
Do not
press it in.
c;> &_ .
A WARNING
-===
If the hood is not latched complete ly, it could
fly up wh ile you are driving and obstruct your
vis ion.
- For safety reasons, the hood must always be
closed securely while driv ing. Because of
this, always check the hood after closing it
to make sure it is latched correctly . The
hood is latched if the front corners cannot
be lifted.
~
305

<( a, .... N ,....
N .... 0 0
3 a,
Audi oil quality standard
Gas oline
VW 502 00 or
engi ne vw 504 00
Diesel vw 507 00
eng ine
A udi recomm ends
~ Castrot /jglQ,Y j;-11Jt ?rtwF«J.o,.11-J.
Audi recomm ends Longlife high perf orma nce
engine oil from Aud i Genuine Parts
Using the proper engine oil is important for the
functionality and service life of the eng ine. Your
engine was factory-filled with a high-quality oil
which can usually be used throughout the entire
year.
(D Note
Your Limited New Vehicle Warranty does not
cover damage or malfunctions due to failure
to follow recommended maintenance and use
requirements as set forth in the Aud i Owner's
Manual and Warranty
& Maintenance booklet .
- Use only a high quality eng ine oil that ex-
pressly complies with the Aud i oil quality
standard specified for your vehicle's engine .
U si ng a ny other oil can cause serious engine
damage.
- Do not mix any lubr icants or othe r additives
i nto the engine oil. Doing so can cause en­
gine damage.
If you need to add oil and there is none availa­
ble that meets the Audi o il quality standard
your eng ine requ ires, you may add a tota l of
no more than 0 .5 qua rt/liter of a h igh-quality
"synthetic"oil that meets the following speci­
fications.
- Vehicles with gasoline engine: AC EA A3 or
API SM with a viscosity grade of SAE OW-30,
SAE SW-30 or SAE 5W-40.
- Vehicles with diesel engine: ACEA C3 or API CF with a viscosity grade of SAE OW-30
or SAE 5W-30.
- For more information about engine oil that
has been approved for your vehicle, please
contact either your authorized Audi dea ler
Ch eck ing and Filling
or Audi Customer Relations at
1 (800) 822-2834 or visit our web site at
www.aud iusa .com or www .a udicanada .ca.
Engine oil consumption
The engine in your vehicle depends on on ade­
quate amount of oil to lubricate and cool all of
its moving ports.
In order to provide effective lubrication and cool ­
ing of internal engine components, all internal
combust ion eng ines consume a certa in amount
of oil. Oil consumption varies from eng ine to en­
gine and may change s ignificantly over the life of
the engine. Typ ically, engines w ith a specified
break-in period (see
c::> page 73) consume more
o il during the break-in per iod than they consume
after oil consumpt ion has stabil ized.
Under normal cond itions, the rate of oil con­
sumption depends on the quality and viscos ity of
the oil, the RPM (revolutions per minute) at
which the engine is operated, the amb ient tem­
peratu re and road co ndit ions. Furt her fac to rs a re
the amo unt of oil di lution from wate r condensa­
tion or fuel residue and the oxidation level of the oi l. As any engine is subject to wear as mileage
builds up, the oil consumption may increase over
time unt il replacement of worn components may
become necessary.
With a ll these variab les coming into play, no
standard rate of oil consumption can be estab­
lished or spec ified . There is no alternative to reg­
ular and frequent checking of the oi l level, see
Not e.
If the yellow engine oil level warning symbo l El
in the instrument cluster lights up, you should
check the oil level as soon as possible
c::> page 308 . Top off the o il at your earliest con­
venience
c::> page 308 .
A WARNING
Before you check anyt hing in the engine com­
partment, always read and heed all WARN­
IN GS
c::> .&. in Working in the engine compart-
ment on page 304. ..,_
307

Checking and Filling
Cooling system
Coolant
The engine coo ling system is filled with a mixture
of pur ified water and coolan t addit ive at the fa c­
tory. This coo lant must not be not changed.
The coolant leve l is monito red throug h the . in­
dicator light~
page 31. Howeve r, we do recom­
mend occasionally check ing the coo lan t level
manually.
I f you must add coolant, use a m ixture of water
and coolant additive. M ixing the coolant additive
with d istilled wate r is recommended.
Coolant additive
The coolant additive is made of anti-freezing a nd
corros ion protection agents. Only use the fo llow­
ing coo lant add it ives. These additives may be
m ixed w ith each other.
Coolant additive Specification
G13
TL 774)
G12++ TL 774 G
The amount of coo lant add itive that needs to be
mixed w it h water depends on the climate where
the vehicle will be operated. If the coolant addi­
tive percentage is too low, the coolant can freeze
and damage the engine.
Coolant Freeze protec-
additive tion
Warm min. 40% m in. -13 °F
reg ions max. 45% (-25 °C)
Cold min. 50% max. -40 °F
reg ions max. 55% (-40 °C)
(D Note
- Befo re the start of winter, have your author­
i zed Audi dealer or authorized A udi Service
Fac ility check if the coolant additive in yo ur
vehicle matc hes the percentage approp riate
fo r the climate. Th is is especially important
when driving in co lde r climates.
- If the appropriate coolant additive is not
available in an emergency, do not add any
other additive. You cou ld damage the en-
310
gine . If this happens, only use water and re ­
store the correct m ixt ure ratio with the
specified coo lant add itive as soon as poss i­
ble.
- On ly ref ill with new coolant .
- Rad iator sealant mus t not be mixed wi th
the coolant.
Adding coolant
Fig. 24 9 Eng ine co mpart m ent: re lease button on coolant
expansio n tank
Check ing the engine coolant level
.,. Park your veh icle on a level surface.
.,. Switch the ignit ion off.
.,. Read the coolant level on the coolant expansion
tank
c:> fig . 249 .
.,. The coolant leve l mus t be between the MIN and
MAX mar kings when the engine in co ld. Whe n
t he engi ne is warm i t ca n be sligh tly above the
MAX mar kin g.
Adding coolant
.,. Let the engi ne cool down.
.,. Place a cloth over the coo lant expansion tank
cap.
.,. Push the rele ase button¢
fig. 249 and carefu l­
ly unsc rew the cap to the left un til you feel re­
sis tance ¢,&. .
.,. Push the release button again and remove the
cap completely.
.,. Make sure that the fluid level remains stab le.
Add more coolant if necessary .
.,. Turn the cap to the right to secure it until you
feel res istance a second time.
Coolant loss usually ind icates there is a leak. Im­
med iate ly dr ive your vehicle to an author ized
Audi dealer or authorized A udi Service Fac ility ..,.

and have the cooling system inspected. If the
cooling system is not leaking, a loss can come
from the coolant boiling through overheating and being pushed out of the cooling system.
A WARNING
- The cooling system is under pressure. Do
not open the coolant expansion tank cap
when the engine is hot. This increases the
risk of burns .
- The coolant add itive and the coolant can be
dangerous to your health. For this reason,
keep the coolant in the original container
and away from children. There is a risk of
poisoning.
- When working in the engine compartment,
remember that the radiator fan can switch
on even if the ignition is switched off, which
increases the risk of injury.
(D Note
Do not add coolant if the expansion tank is
empty. There may be a ir in the cooling sys­
tem, which increases the risk of engine dam­
age . If this is the case, do not continue driv­
ing . See an authorized Audi dealer or author­
ized Audi Service Facility for assistance.
Brake fluid
Checking brake fluid level
The brake fluid level can be checked with a quick
glance .
Fig. 250 Engine compa rtment: Cover o n the brake fluid
rese rvoir
Before you check anything in the eng ine compart ­
ment,
always read and heed all WARNINGS
Checking and Filling
c::> .&. in Working in the engine compartment on
page 304.
" Read the brake fluid level from the brake fluid
reservoir
c::> fig. 250, c::> page 306, fig. 247. The
brake fluid level must be between the "MIN"
and "MAX" markings.
The brake flu id reservoir is located at the rear
partition of the engine compartment on the left
side
~ page 306 .
The fluid level may drop slightly after some time
due to the automatic adjustment of the brake
pads . This is not cause for alarm.
If the brake fluid level falls considerably below
the "MIN" mark, the brake warning/indicato r
light (USA models:
11111 , Canada models : II>
will come on c::> page 29. Do not continue to oper­
ate the vehicle. The complete brake system
should be thoroughly checked by an authorized
Audi dealer or qualified workshop and the cause
corrected . If the brake fluid level is too low, the
brake warning/indicator light will illuminate .
Contact an authorized Audi dealer
immediately .
@ Tips
The brake fluid reservoir is located under­
neath the cover.
Changing brake fluid
Hove the broke fluid changed by on experienced
technician.
Brake fluid absorbs moisture from the air. If the
water content in the brake fluid is too high, cor­
rosion in the brake system may result after ape­
riod of time. The boiling point of the brake fluid
will also decrease considerably and decrease braking performance .
Therefore, the brake fluid must be changed
every
two years .
Always use new brake fluid which con­
forms to Federal Motor Vehicle Standard "FMVSS
116 DOT 4" .
The brake fluid reservoir can be difficult to reach,
therefore, we recommend that you have the brake fluid changed by your authorized
Audi
dealer.
Your dealer has the correct tools, the
311