auxiliary battery AUDI S4 2021 Owners Manual

Checking and Filling


accident. Do not continue driving. See an au-
thorized Audi dealer or authorized Audi
Service Facility for assistance.
— If the brake fluid is old, bubbles may form in
the brake system during heavy braking. This
could impair braking performance and driv-
ing safety, which increases the risk of an ac-
cident.
— The brake fluid in your vehicle must meet
the standard VW 501 14 and is available at
an authorized Audi dealer or authorized
Audi Service Facility. If this brake fluid is not
available, another high-grade brake fluid of
equivalent quality may be used, and it must
meet the U.S. Federal Motor Vehicle Stand-
ard (FMVSS) 116 DOT 4, Class 6.

Switch off all electrical equipment that is not
needed. If necessary, some equipment will be
switched off automatically. Vehicle functions or
driving stability may be limited. Drive to an au-
thorized Audi dealer or authorized Audi Service
Facility immediately.
z= Electrical system: low battery charge. Bat-
tery
will be charged while driving
The starting ability may be impaired.
If this message turns off after a little while, the
vehicle battery has charged enough while driving.
If this message does not turn off, drive immedi-
ately to an authorized Audi dealer or authorized
Audi Service Facility.

@) Note
— If the brake fluid level is above the MAX
marking, brake fluid may leak out over the
edge of the reservoir and result in damage
to the vehicle.
— Do not allow any brake fluid to come into
contact with the vehicle paint, because it
will corrode the paint.
Electrical system
If the = / B or = indicator light turns on,
there is a malfunction in the power supply, the
battery, or the vehicle electrical system.
mz / B Electrical system: malfunction! Safely
stop vehicle
Do not continue driving and switch the ignition
off > A\. See an authorized Audi dealer or author-
ized Audi Service Facility for assistance.
= Electrical system: malfunction! Restart not
possible. Please contact Service
If you switch the ignition off, you will not be able
to restart the vehicle. Vehicle functions or driving
stability may be limited. Drive to an authorized
Audi dealer or authorized Audi Service Facility im-
mediately.
= Electrical system: malfunction! Please con-
tact Service
230
ZA\ WARNING
When there is an electrical system malfunc-
tion, vehicle functions may not work and driv-
ing stability may be limited, which increases
the risk of an accident. Do not continue driv-
ing and switch the ignition off. See an author-
ized Audi dealer or authorized Audi Service Fa-
cility for assistance.

Battery
ela lame (Tem eeecela)
Because of the complex power supply, all work on
batteries such as disconnecting, replacing, etc.,
should only be performed by an authorized Audi
dealer or authorized Audi Service Facility > A\.
Multiple batteries with different technologies
may be installed in your vehicle:
— Vehicle battery (for example, for starting the
engine, basic power supply) > page 231, 12
Volt vehicle battery or > page 232, Other bat-
tery types
— Auxiliary battery (for example, for recuperation
or optional equipment) > page 232, Other bat-
tery types
Not running the vehicle for long periods of
time
The battery will gradually drain if the vehicle
does not run for long periods of time. To ensure >

Fuses and bulbs


2 | Audi phone box

Right front seat electronics, lumbar sup-
port, massaging seat
4 |Side assist


6 |Tire pressure monitoring system

Convenience access and start authoriza-
tion control module

8 | Auxiliary heating, tank module

TV tuner, data exchange and telematics
10 control module

11 | Auxiliary battery control module

12 | Garage door opener

13 | Rearview camera, peripheral cameras
14 | Right tail lights
16 | Airbag control module



No. | Equipment

Exhaust treatment
Right trailer hitch light
Trailer hitch
Left trailer hitch light
Trailer hitch socket


WO)
O};N]/
Mm|
Ww

All wheel drive control module, sport dif-
10
ferential


11 | Exhaust treatment

Bulbs
Replacing bulbs
Audi recommends having a bulb replaced by an
authorized Audi dealer or authorized Audi Service
Facility in cases of doubt. These facilities have
the correct tools and replacement parts as well
as the required technical knowledge.
LED lights*
Your vehicle is equipped with maintenance-free
headlights and tail lights. However, if a light bulb
needs to be replaced, please contact an author-
ized Audi dealer or authorized Audi Service Facili-
ty.
276

If you still would like to try replacing the
bulbs in your vehicle yourself, read the warn-
ings regarding working in the engine compart-
ment > A\ in General information on
page 221.

Make sure the covers are fitted correctly on
the headlight and tail light so that no water
will leak in from the outside and the light
function will not be impaired.