›› Y7 is a LIN user of the Vehicle Electrical System Control
Module J519 and can, therefore, be accessed via Address
Word 09 with the VAS Scan Tool.

›› Glare sensors located behind trans-reflective (semipermeable) glass – not visible to the driver.

Schematic diagram

J533

J519

EX5

Y7

G399
664_129

Key:
EX5
G399
J519
J533
Y7

48

Interior Rear View Mirror
Light Recognition Sensor
Vehicle Electrical System Control Module
Data Bus on Board Diagnostic Interface
Automatic Dimming Interior Rearview Mirror

If the incidence of light on the rear-view mirror is impaired,
the automatic dimming mirrors will not function properly.

The automatic dimming mirrors are not dimmed when the
inteiror lighting is on and when reverse gear is selected.

Rear-view mirror EX5

664_130

Rain/Light Recognition
Sensor
G397

Light Recognition Sensor
G399
(concealed behind the mirror glass)

Automatic Dimming Interior Rearview Mirror
Y7

49

Windshield wiper and washer system
Windshield washer system
The standard windshield washer system is similar in design
and working principle to the systems used on previous Audi
models. The wiper linkage integrated in the plenum
chamber including the wiper motor with integrated control
unit drives two wiper arms with Aero wiper blades.

Wiper Motor Control Module J400 is a LIN slave of the
Vehicle Electrical System Control Module J519 and has a
number of functions:
›› Touch wipe.
›› Tear drop wipe.
›› Alternating park position of the wiper blades.
›› Speed reduction at reversal points.
›› Speed-dependent wiping speed.
›› Service position of the wiper arms for wiper blade
replacement.

Washer fluid tank with Windshield
Washer Pump
V5
Wiper Motor Control Module
J400

664_102

Function diagram
The signals from Windshield Wiper Switch E are sent to the
Data Bus on Board Diagnostic Interface J533 by the Steering Column Electronics Control Module J527 via FlexRay.
These messages are then transfered to the Vehicle Electrical System Control Module J519 via comfort/convenience
systems CAN 2.
Windshield Wiper
Switch
E
Steering Column Electronics Control Module
J527

FlexRay

J519 activates the Wiper Motor Control Module J400 via
the LIN connection.
Windshield Washer Pump V5 is activated by J519 (it is
discretely wired).

Data Bus on Board
Diagnostic Interface
J533

Comfort/convenience
systems CAN 2
Electrical system
control unit
J519

LIN

Wiper Motor Control
Module
J400

Discrete
wiring

Windshield Washer
Pump
V5
50

664_103

Windshield washer
The standard windshield washer system consists of the
washer fluid tank with windshield washer pump, the
washer fluid hoses and the three windshield washer jets.
The windshield washer jets are integrated into the underside of the hood.

They are heatable and have an adjusting screw for exact
adjustment and optimal distribution of the washer fluid on
the windshield. The washer jet heating resistors are energized directly by Vehicle Electrical System Control Module
J519.

Wash water connection

Jet heater connection

Adjusting screw

Windshield washer jet

664_104

Three windshield washer jets on
the underside of the hood

51

Adaptive windshield wiper with integrated washer jets (wet arm wipers)
General description
The 2019 A8 may be equipped with adaptive windshield
washers (cold weather package) with integrated washer
jets. These are also known commonly as wet arm wipers. In
this version the windshield washer jets are integrated in
both wiper arms above and below the wiper blade. Both of
the washer jet channels in each wiper arm are heated.

The washer fluid is applied to the windshield directly next
to the wiper blade, which provides better cleaning results
and water economy compared to the standard windshield
wiper system. There is no splash of water onto windshield
to impair the driver's visibility. This means that the driver
has a clear view during the wiping cycle.

Washer jets above wiper blade are active

664_109

Washer jets below wiper blade are active

664_163

52

Windshield washer system
The wiper linkage and the Wiper Motor Control Module
J400 are identical to those of the standard windshield
washer system. The wet arm wipers have 2 integrated,
heatable washer jet channels each.

Each wiper arm has two washer fluid connections for both
washer jet channels as well as an electrical connection for
the heating resistors.

Washer fluid connections

664_108

Connections for the heating resistors

Wiper arms
Two washer jet channels are integrated in each wiper arm,
one for the windshield washer jets on the top of the wiper
blade and one for the windshield washer jets on the bottom
of the wiper blade. 11 jet outlets are integrated into in each
washer jet channel.

The jet at the tip of the washer jet channel is designed as
an adjustable ball nozzle. The direction of the washer fluid
outlet can be controlled. All other jets are non-adjustable.

Adjustable ball nozzle

Windshield washer jets,
non-adjustable

664_106

664_107

53

Windshield Washer Pump Control Module J1100
General description
Models with the optional wet arm wipers feature a newly
developed control module: Windshield Washer Pump
Control Module J1100. It is located in the plenum chamber
and uses a pulse-width-modulated (PWM) signal to activate
both Windshield Washer Pump V5 and the heating resistors
in the wiper arms.

The windshield washer pump of the wet arm wiper system
is designed as a dual pump. When the pump turns in one
direction, the windshield washer jets on the top of the
wiper arm are supplied with washer fluid. When the pump
turns in the opposite direction, the windshield washer jets
on the bottom of the wiper arm are active.

Windshield Washer Pump Control
Module
J1100

664_111

Function diagram
Windshield Washer Pump Control Module J1100 is a slave
of Vehicle Electrical System Control Module J519. The wiper
motor sensor, the rain light and moisture sensor as well as
the light switch are connected to the same LIN branch.

Vehicle Electrical System
Control Module
J519

Windshield Washer Pump Control Module
J1100
Thermal Resistor 1 in Driver Side Windshield Wiper Arm Z139 and Thermal Resistor 1 in Front Passenger Side Windshield
Wiper Arm Z141

LIN
Terminal 30
Terminal 31

PWM

PWM

Windshield Washer Pump
V5
664_114

54

Operating the windshield washer pump

The PWM signal controls both the quantity of washer fluid
and the time at which water is applied to the windshield.
The windshield washer jets on the top or bottom of the
wiper blade are selected when the pump reverses direction.
The way in which the windshield washer pump is activated
depends on the ambient temperature, the position of the
wiper arm and the speed at which the vehicle is travelling.
Basically, a distinction is made between two characteristics:
winter mode and summer mode. Winter mode is active at
temperatures below 41 °F (5 °C). When the ambient temperature rises above 44.6 °F (7 °C), the summer mode
characteristic is selected. Each mode (summer/winter) is
subdivided into a further four characteristics, depending on
the speed at which the vehicle is travelling.
Diagram 1

This means that, overall, there are eight different scenarios
for the activation of the windshield washer pump. The
diagrams below show how the windshield washer pump is
activated in winter model one. The first diagram shows the
movement of the wiper blade from the lower reversal point
to the upper reversal point. In the area highlighted red the
windshield washer jets on the top of the wiper blade are
activated, while in the area highlighted blue the windshield
washer jets on the bottom of the wiper blade are activated.
The second diagram shows the water distribution during
the movement of the wiper blade from bottom to top. The
washer jets on the opposite side are activated shortly
before the reversal point is reached.

Top wiper arm reversal point

Windshield washer jets on bottom of wiper blade are active

Wiping direction

Windshield washer jets on top of wiper blade are active

Bottom wiper arm reversal point
664_115

Top wiper arm reversal point
Diagram 2

Windshield washer jets on bottom of wiper
blade are active
Wiping direction

Bottom wiper arm reversal point
Windshield washer jets on top of wiper
blade are active

664_116

The heating resistors in the wiper arms are also activated
by a PWM signal. The heating resistors are not activated at
ambient temperatures above 39.2 °F (4 °C). At an ambient
temperature of 28.4 °F (-2 °C) and below, the heating
resistors are fully activated (100 % PWM signal). Between
these two temperature values, the PWM signal has a linear
characteristic.

PWM signal

Activation of the heating resistors

Temperature
664_117
55

Washer system for headlights and night vision
General description
The 2019 A8 can be equipped with a headlight washer
system with two washer jets per headlight. The washer jets
are concealed below covers in the bumper and do not
extend until they are activated.

If the vehicle is equipped with night vision assist, the
accompanying camera also has a washer jet. Both systems
are supplied with washer fluid by a common pump.
Washing is initiated by the driver via the wiper stalk.

Cover for headlight
washer system jets

Cover for headlight
washer system jets

Night Vision System Camera
R212

Washer jet

664_105

Function diagram
A condition for cleaning the headlights and the camera for
the night vision system is that the driving lights are on.
When Vehicle Electrical System Control Module J519
receives information via a LIN connection from the light
switch that the low beam is on, or when the rain and light
sensor indicates that it is dark. If Windshield Wiper Switch
E is now actuated, its signal is sent to J533 by the Steering
Column Electronics Control Module J527 via FlexRay.

Windshield Wiper
Switch
E
Steering Column Electronics Control ModuleJ527

FlexRay

These messages are then transfered to Vehicle Electrical
System Control Module J519 via comfort/convenience
systems CAN 2.
J519 then activates Headlamp Washer System Pump V11.
The headlights and the night vision system camera are
cleaned when the wiper stalk is actuated for the first time,
and then at preset intervals. Night vision assist does not
have to be activated.

Data Bus on Board
Diagnostic Interface
J533

Comfort/convenience systems CAN 2

Vehicle Electrical System Control Module
J519

Discrete
wiring

Headlamp Washer
System Pump V11
V11

56

LIN

Light Switch
E1

Rain/Light Recognition Sensor
G397

664_112

Laser scanner washer system
General description
The 2019 A8 available with adaptive cruise assist. This
system includes a laser scanner for the recognition of
objects in front of the vehicle. The laser scanner forms a
unit together with the Laser Distance Regulation Control
Module J1122. If dirty, the laser scanner must be cleaned
to ensure that it functions properly.

This is done by a washer jet on the left and right hand sides
of the laser scanner. If Laser Distance Regulation Control
Module J1122 detects that the signals from the laser
scanner are too weak, it automatically requests a cleaning
cycle. The driver cannot activate this cleaning function.

Laser Distance Regulation Control
Module
J1122

Washer jets
664_113

Function diagram
Laser Distance Regulation Control Module J1122 requests
that its laser scanner be cleaned. It sends a data message
via FlexRay to Data Bus on Board Diagnostic Interface J533,
which in turn transfers the message to Vehicle Electrical
System Control Module J519 via comfort/convenience
systems CAN 2. J519 must now activate Rear Window
Washer Pump V13. V13, which then takes care of cleaning
the laser scanner. The characteristic of this activation signal
is dependent on the equipment fitted.

Laser Distance Regulation Control Module
J1122

FlexRay

There are two possible scenarios:
1. The vehicle is equipped with a standard wiper system and
a laser distance control system:
›› J519 sends a LIN message to the Windshield Washer
Pump Control Module J1100, which activates V13 via
discrete wiring.
2. The vehicle is equipped with a wet arm wiper system and
a laser distance control system:
›› J519 activates V13 directly via discrete wiring.

Data Bus on Board
Diagnostic Interface
J533

Comfort/convenience systems CAN 2

Vehicle Electrical
System Control
Module
J519

Discrete
wiring

Rear Window
Washer Pump
V13

LIN

Windshield Washer
Pump Control Module
J1100

Discrete
wiring

Rear Window
Washer Pump
V13

664_118

57

Rear view camera washer system
General description
Due to the fact that the rear view camera is installed in the
trunk lid handle, it is prone to being obstructed by dirt
build-up under certain ambient conditions. The 2019 A8
has a washer jet for cleaning the camera lens. Camera lens
cleaning can be initiated in two ways by brief activation of
the washer jet.

1. Driver-initiated cleaning cycle:
›› The driver has the option of initiating a rear view
camera lens cleaning cycle in the parking aid settings
menu. To do this, the driver selects the "Clean reversing
camera" option.
2. Cleaning cycle requested by the rear view camera:
›› If Rearview Camera System Control Module J772 determines that the camera lens is dirty when evaluating the
camera images, it initiates a cleaning cycle.

Washer jet

Rearview Camera System Control
Module
J772
664_119

Function diagram
If the rear view camera cleaning cycle is initiated by the
driver, Information Electronics Control Module 1 J794
sends a corresponding message to Data Bus on Board
Diagnostic Interface J533 via the infotainment CAN. If
cleaning of the camera lens is requested, J533 receives a
corresponding message from the Rearview Camera System
Control Module J772 via extended CAN.

Information Electronics
Control Module 1
J794

Infotainment CAN

This second option is only implemented in models in which
the rear view camera is installed in combination with the
surround view camera. The data is transfered from J533 to
the Vehicle Electrical System Control Module J519 via
comfort/convenience systems CAN 2. Depending on equipment, J519 activates either Windshield Washer Pump V5 or
Rear Window Washer Pump V13 via the discrete wiring.

Data Bus on Board
Diagnostic Interface
J533

Extended CAN

Rearview Camera System
Control Module
J772

Comfort/convenience systems CAN 2

Vehicle Electrical
System Control
Module
J519