2020 AUDI A3 wiring

High-voltage system

High-voltage system
General information
Introduction
Applies to: vehicles with plug-in hybrid drive
All work done on the high-voltage system must
only be performed by certified high-voltage tech-
nicians at authorized Audi dealers or authorized
Audi Service Facilities in accordance with Audi
guidelines.
The high-voltage system is composed of the fol-
lowing high-voltage components, among other
things: the high-voltage battery, the power elec-
tronics, the electric motor, the high-voltage A/C
compressor, the high-voltage heater, the charg-
ing system and charging port, and the orange
high-voltage wiring.
The high-voltage battery is located on the vehicle
underbody in front of the rear axle and does not
require any maintenance from the driver.

ZA WARNING
The voltage in the high-voltage system is life-
threatening. Touching a damaged high-volt-
age component can result in a fatal electric
shock. The components in the high-voltage
system are marked with a warning label which
warns against the high-voltage.
— The voltage level in the high-voltage system
is still dangerous and potentially life-threat-
ening when the ignition is switched off.
— Never perform work on the orange high-
voltage cables or on other high-voltage
components. Only authorized repair facili-
ties that are certified may perform work on
the high-voltage system.
— Never damage, alter or remove the orange
high-voltage cable or disconnect it from the
high-voltage system.
— Never perform any work using cutting, shap-
ing or sharp-edged tools or heat sources
near the high-voltage system and high-volt-
age cables.
— Gases that escape from the high-voltage
battery can be poisonous or flammable.

96

— Damage to the high-voltage battery could
cause the high-voltage battery to leak im-
mediately or in the future, and poisonous or
flammable gases could escape. Do not in-
hale the gases!
— Do not expose yourself to any leaking fluids
and do not come into contact with them.
— The high-voltage battery electrolyte fluid is
caustic. If electrolyte fluid comes into con-
tact with the skin, flush the affected area for
at least 15 minutes with clean water. Then
wash the affected area with soap. Have the
affected area examined by a medical profes-
sional.
— In the event of a technical emergency, in-
form the responders that the vehicle is
equipped with a high-voltage battery.
@) Note
— The high-voltage system can be damaged if
the vehicle underbody comes into contact
with the ground. Immediately drive your ve-
hicle to an authorized repair facility and
have it inspected.
— The electric drive motor can become very
hot during operation. Do not stop the vehi-
cle if there is oil, fuel residue or other flam-
mable substances under or next to the vehi-
cle.
Special considerations for the high-voltage
battery
Applies to: vehicles with plug-in hybrid drive

Please first read and note the introductory infor-
mation and heed the warnings > page 96.
All batteries age with use and over time. There
are things you should know about the care of the
high voltage battery that will help it keep giving
you good service and reliability over time. Please
read and keep the following information in mind
while you enjoy the performance and economy of
your vehicle.
— Be sure to charge the high voltage battery be-
fore leaving the vehicle parked and unused for a
longer period of time. Ideally the high-voltage >

Airbag system


— If you are unrestrained, leaning forward, sit-
ting sideways or out of position in any way,
your risk of injury is much higher.
— You will also receive serious injuries and
could even be killed if you are up against the
airbag or too close to it when it inflates -
even with an Advanced Airbag > page 253.

Z\ WARNING
A child in a rearward-facing child seat instal-
led on the front passenger seat will be seri-
ously injured and can be killed if the front air-
bag inflates - even with an Advanced Airbag
System.
— Although the Advanced Airbag System in
your vehicle is designed to turn off the front
airbag when a rearward-facing child re-
straint has been installed on the front pas-
senger seat, nobody can absolutely guaran-
tee that deployment is impossible in all con-
ceivable situations that may happen during
the useful life of your vehicle.
— The inflating airbag will hit the child seat or
infant carrier with great force and will
smash the child seat and child against the
backrest, center armrest, door, or roof.
— Always install rearward-facing child re-
straints on the rear seat.
— If you must install a rearward facing child
seat on the front passenger seat because of
exceptional circumstances and the PASSEN-
GER AIR BAG OFF light does not come on
and stay on, immediately install the rear-
facing child seat in a rear seating position
and have the airbag system inspected by
your Audi dealer.

Z\ WARNING
If, in exceptional circumstances, you must in-
stall a forward-facing child restraint on the
front passenger's seat:
— Always make sure the forward-facing seat
has been designed and certified by its manu-
facturer for use on a front seat with a pas-
senger front and side airbag.

260
— Never put the forward-facing child restraint
up against or very near the instrument pan-
el,
— Always move the front passenger seat to the
highest position in the up and down adjust-
ment range and move it back to the rear-
most position in the seat's fore and aft ad-
justment range, as far away from the airbag
as possible, before installing the forward-
facing child restraint.
— Always make sure that the safety belt upper
anchorage is behind the child restraint and
not next to or in front of the child restraint
so that the safety belt will be properly posi-
tioned.
— Always make sure that there is nothing on
the front passenger seat that will cause the
capacitive passenger detection system in
the seat to signal to the Airbag System that
the seat is occupied by a person when it is
not, or to signal that it is occupied by some-
one who is heavier than the person actually
sitting on the seat. The presence of addi-
tional objects could cause the passenger
front airbag to be turned on when it should
be off, or could cause the airbag to work ina
way that is different from the way it would
have worked without the object on the seat.
— Make sure that the PASSENGER AIR BAG
OFF light comes on and stays on all the time
whenever the ignition is switched on.
Advanced Airbag System components
The front passenger seat in your vehicle has a lot
of very important parts of the Advanced Airbag
System in it. These parts include the capacitive
passenger detection system, wiring, brackets,
and more. The control unit monitors the system
on the front passenger seat when the ignition is
switched on and turns the airbag indicator light
on
when a malfunction in the one of the system
components is detected > page 265. Because the
front passenger seat contains important parts of
the Advanced Airbag System, you must take care
to prevent it from being damaged. Damage to

>

8V2012721BK
Airbag system

Monitoring the
Advanced Airbag System

‘oring indicator light
Two separate indicators monitor the function of
the Advanced Airbag System: the ka light and
the PASSENGER AIR BAG OFF light.
The Advanced Airbag System as well as the side
airbags and side curtain airbags with ejection
mitigation features (including the electronic con-
trol unit, sensors and system wiring) are all
monitored continuously to make sure that they
are functioning properly whenever the ignition is
on. Every time you turn on the ignition, the air-
bag system indicator light ka will come on fora
few seconds (function check).
The system must be inspected when the
indicator light Ba:
— does not come on when the ignition is switched
on,
— does not go out a few seconds after you have
switched on the ignition, or
— comes on while driving.
If an airbag system malfunction is detected, the
indicator light will come on to serve as a constant
reminder to have the system inspected immedi-
ately.
If a malfunction occurs that turns the front air-
bag on the passenger side off, the PASSENGER
AIR BAG OFF light will come on and stay on
whenever the ignition is on.

ZA\ WARNING
An airbag system that is not functioning prop-
erly cannot provide supplemental protection
in a frontal crash.
- If the airbag indicator light > page 238
comes when the vehicle is being used, have
the system inspected immediately by your
authorized Audi dealer. It is possible that
the airbag will inflate when it is not sup-
posed to, or will not inflate when it should.

PASSENGER AIR BAG OFF light


B8V-0215

Fig. 218 Center console: passenger airbag off warning
light
The PASSENGER AIR BAG OFF light is located in
the center of the instrument panel > fig. 218.
The PASSENGER AIR BAG OFF light will come on
and stay on to tell you when the front Advanced
Airbag on the passenger side has been turned off
by the electronic control unit. If the bulb for the
PASSENGER AIR BAG OFF light burns out, the
airbag indicator light 2 will come on to signal a
malfunction in the Advanced Airbag System. Al-
though the burned-out bulb will not change the
way the front passenger's frontal airbag works, it
will no longer be possible to use the PASSENGER
AIR BAG OFF light to make sure that the airbag
on/off status is correct for the occupant on the
front passenger seat. Have the airbag system in-
spected immediately by your authorized Audi
dealer.
The PASSENGER AIR BAG OFF light will blink
for about 5 seconds when:
— the ignition is switched on and
— the capacitive passenger detection system,
which switches the front seat passenger's fron-
tal Advanced Airbag on and off, detects a
change in the status of the front passenger
seat.
As soon as the PASSENGER AIR BAG OFF light
stops blinking, always make sure that the airbag
status
(on or off) as shown by the PASSENGER
AIR BAG OFF light is proper for the age, size and
electrical capacitance of the person occupying
the front passenger seat. Always make sure that
the safety belt for the front passenger seat is
properly fastened.
265

8V2012721BK
Accessories and technical changes

Usually maintenance and repair work requires
special tools, measuring devices, and other
equipment that is available to trained vehicle
technicians in order to help ensure that your vehi-
cle and all of its systems operate correctly, relia-
bly, and safely. Performing work on the vehicle
incorrectly can impair the operation and reliabili-
ty of your vehicle and may void one or more of
your vehicle's warranties.
Technical Modifications
Interference with electronic components, their
software, the wiring, and data transfer may cause
malfunctions. Because of the way electronic com-
ponents are interconnected, such malfunctions
can also impair systems that are not directly in-
volved. This means that you risk both a substan-
tial reduction in the operational safety of your ve-
hicle and increased wear of vehicle components.
Some convenience functions, such as the conven-
ience turn signal function, individual door open-
ing function, and displays, can be reprogrammed
using special workshop equipment. If functions
are reprogrammed, the information and descrip-
tions about these functions in this Owner's Man-
ual may no longer apply to the changed func-
tions. Audi recommends that an authorized Audi
dealer or authorized Audi Service Facility perform
and verify any reprogramming procedures.


carry out the job and have the correct tech-
nical information and the correct tools.
— If you are uncertain about what to do, have
the work performed by an authorized Audi
dealer, an authorized Audi Service Facility,
or another qualified workshop. Serious per-
sonal injury may result from improperly per-
formed work.


ZA WARNING
Maintenance procedures, repairs, or technical
modifications that are performed incorrectly
increase the risk of an accident and can lead
to serious injuries.


ZA WARNING
The engine compartment of any motor vehicle
is a potentially dangerous area and can cause
serious personal injury.
— Always use extreme caution when doing any
work in the engine compartment. Always
follow commonly accepted safety practices
and use common sense. Never risk personal
injury.
— Never perform any work in the engine com-
partment unless you know exactly how to

@) Note
— Maintenance procedures, repairs or techni-
cal modifications that are performed incor-
rectly can cause damage to the vehicle, such
as corrosion.
— If emergency repairs must be performed,
take your vehicle to an authorized Audi deal-
er or authorized Audi Service Facility as soon
as possible.
— Audi is not liable for damage to the vehicle
resulting from failure to comply with these
guidelines.
@) For the sake of the environment
— Regular maintenance can help protect the
environment.
— Technical modifications to the vehicle can
have a negative impact on fuel consumption
and vehicle emissions.
(@) For the sake of the environment
Undeployed airbag modules and pretension-
ers are classified as Perchlorate Material -
special handling may apply, See www.dtsc.ca.
gov/hazardouswaste/perchlorate. When the
vehicle or parts of the restraint system includ-
ing airbag modules and safety belts with pre-
tensioners are scrapped, all applicable laws
and regulations must be observed. Your au-
thorized Audi dealer is familiar with these re-
quirements and we recommend that you have
your dealer perform this service for you.
G) Tips
Because of your vehicle's aluminum body de-
sign, all service and repair procedures affect-
ing the body should be performed by an au-
thorized Audi dealer or authorized Audi
375