Oil bleed port for double
shaft oil seal

Oil change intervals
The Haldex oil must be changed every 3 years, regardless of
mileage. The axle oil is not subject to a change interval.

Note

Haldex oil and rear axle oil are NOT the same. Do not mix them up during service work or irreparable damage
to components will occur.
20

Engine/transmission mounting
The engine/transmission mounting is a key factor in
reducing unwanted noise and vibration transfer to the
passenger compartment.

The engine torque is absorbed by the stabilizer link rod,
which is designed as an elastomer bearing and connected
directly to the gearbox and vehicle body via the subframe.

The hydraulic damping in the bearings essentially reduces
low frequency engine/transmission movements to optimize
occupant comfort.

Overview

Hydraulic engine bearing
Damping fluid with injector plate

Carrier part

Support arm

Diaphragm

Hydraulic transmission bearing

602_097

Stabilizer link bar

21

Fuel system
The Q3 has a 16.9 gal (64.0l) saddle-type fuel tank. The
fuel tank version for the North Amerian market will also
have the required ORVR system (not shown.)

The lever-type sensor is mounted to the bottom-supported
swirlpot of the fuel delivery unit. Fuel supply is regulated
according to demand. Only the actual amount of fuel
needed is made available. Brushless, electrically
commutated fuel pumps are used.

A lever-type sender in each of the main and secondary
chambers ensures a high display accuracy. A three-wire
thick film sensor is used. The additional wire supplies a
redundant signal which is used to arithmetically eliminate
contact resistance factors created by the use of aggressive
fuels. Consequently, resistance is no longer a factor
affecting the accuracy of the display.

Fuel tank and fuel level sender

Connections for the activated charcoal filter (ACF)

Lever-type sender

Expansion tank
Bracket for
Fuel Pump Control Module J538
Float-type vent valve
with roll-over function

Main chamber

Fuel Pump
G23
Lever-type
sender 1
Lever-type
sender 2
Tank ventilation
Suction jet pump

Secondary
chamber
602_096

22

Exhaust system
The overall weight of the exhaust system was kept low
through the use of high grade stainless steel, low wall
thickness pipes and lightweight mufflers.

Both ceramic and metal catalytic converter substrates are
used in the exhaust gas after treatment system. To reduce
structure-borne sound, the shells of the rear silencer have
reinforcing beads.

Due to its low weight and low exhaust backpressure, the
overall catalytic converter and silencer system significantly
reduces CO2 emissions.

The 2.0l TFSI engine

Close-coupled catalytic converter with ceramic substrate

Decoupling element

Catalytic converter with ceramic substrate

Center muffler
(designed as a reflection muffler)

Rear muffler
(designed as an absorption muffler)

602_098

23

Running gear
Overview
A fundamental goal in the development of the suspension
system for the Audi Q3 was to set new standards in driving
experience in this premium SUV segment.

A vehicle weight distribution of 58% on the front suspension, the wide front and rear vehicle tracks, and the use of
larger diameter wheel and tire combinations enhances the
excellent driving characteristics of the Q3.

To achieve this, use is made of a newly designed MacPherson strut front axle with aluminium wishbones and a multilink rear suspension.

Versions
Only the standard suspension version will be available at
the launch of the Q3.

602_043

24

Front suspension
The front suspension of the Q3 is based on the transverse
platform (MQB) used throughout the Group.
A key new development is the control arm rear bearing. It is
a major factor contributing to outstanding steering
response and agility. Minimal bearing motion in the transverse direction provides a high camber thrust rate and
optimal cornering stability.
The front axle configuration in combination with the design
of the rubber bearings results in neutral handling at the
limit of adhesion with a slight understeer.
A large positive caster angle and wheel offset provides
excellent straight line stability.

602_044

Linear-rate steel springs with
progressive-rate polyurethane auxiliary
springs

Tube-type anti-roll bar

Anti-roll bar link

Coil-over suspension strut bearings with
separate spring/damper mountings

602_045

The control arm and wheel
carrier are connected by a
ball joint.

Wishbone
(forged aluminum part)

Three-piece engine/transmission
mounting
(aluminium chill casting)

Wheel carrier
(nodular cast iron)

25

Rear suspension
The rear suspension components of the front wheel drive
and quattro models are identical.

Upper control arm
(Welded sheet metal)

Spring link
(Welded steel)

Engine/final drive mount
(Sheet steel construction)

High-strength linearrate steel spring

602_046

Anti-roll bar link
(Steel construction)

Tie rod
(Sheet steel construction)

Suspension alignment
The front axle camber can be adjusted by equalization.
Front toe can be adjusted individually. Toe and rear camber
can be adjusted individually on the rear suspension.

Thin-walled
tubular anti-roll bars

Wheel carrier
(Aluminum
casting)

Wheel bearing with
integral wheel hub

Brake system
Overview
The Q3 uses a high performance ABS/ESP system by TRW
specially designed to meet the demands of an SUV.
The use of an electromechanical parking brake allows the
additional features of Hold Assist and speed dependent
emergency braking to be available for the Q3.

602_049

Brake specifications
Front axle

Rear axle

Engine type

2.0l TFSI

2.0l TFSI

Brake type

16“ FN3 57/25/13.5 floating caliper brake

16“ CII 41 EPB aluminium floating caliper with
actuators for the Electric Parking Brake (EPB)

Number of pistons

1

1

Piston diameter

2.24 in (57 mm)

1.61 in (41 mm)

Brake disc diameter

12.3 in (312 mm), vented brake discs

11.1 in (282 mm), solid brake discs

27

Brake servo and master brake cylinder
An 11-inch single brake booster with a “single rate”
characteristic is used on the Q3.
The aluminum tandem master brake cylinder with a 0.9 in
(23.8 mm) diameter provides the necessary performance
with short brake pedal travel and a low pedal actuation
force.
A non-contact Hall sensor is used to actuate the brake
lights.

602_052

Brake application
The foot pedal assembly is a modular design to save
weight. The pedals are manufactured from fiber-reinforced
plastic while the brake pedal bearing assembly is
manufactured as a sheet steel component with a weight
saving shell design.

612_030

Service operations
The service operations on the brake system are the same as
for systems already in use on other Audi models.

28

Electro-mechanical parking brake (EPB)
Design and operation
The Q3 uses an electromechanical parking brake system
similar those used in other Audi models.
In the Q3, Transverse Acceleration Sensor G200, Rotation
Rate Sensor G202 and Longitudinal Acceleration Sensor
G251 are integral with Electromechanical Parking Brake
Control Module J540. These integrated sensors replace ESP
Sensor Unit G419.

Parking Brake Pressure Switch
F234

Right Parking Brake Motor
V283

Electromechanical Parking Brake Control Module J540 with
Transverse Acceleration Sensor G200, Rotation Rate Sensor
G202 and Longitudinal Acceleration Sensor G251

602_054

Left Parking Brake Motor
V282

Service operations
If Electromechanical Parking Brake Control Module J540 is
replaced, it must be coded online. After the online coding,
the basic setting procedure must be carried out to calibrate
Transverse Acceleration Sensor G200 and Longitudinal
Acceleration Sensor G251.
29

ESP
Design and operation
The Audi Q3 uses and ABS/ESP system by TRW (TRW 450).
In addition to the basic functions EBD, ABS, ASR, EDL and
ESP, the following additional functions have been implemented:
Standard features:

•
•
•
•
•
•

Torque vectoring on vehicles with quattro drive
Hydraulic Brake Assist
Hydraulic brake booster
Brake disc wiper
Hydraulic brake fading compensation
Driver steering recommendation (DSR)
602_055

Active wheel speed senders are used on the Audi Q3.

602_056

Service operations
The ABS/ESP Control Module and hydraulic unit can be
sepa­rated for repair. The same condition applies here as to
the other Audi models: control modules can be replaced
indi­vidually but the entire ABS/ESP module must be
replaced if hydraulic modules are faulty.

After replacing an ABS/ESP Control Module, it must be
encoded online. Steering Angle Sensor G85 must be
calibrated and initialized through Power Steering Control
Module J500.
Several basic settings must then be configured. At the
same time, the brake pressure, longitudinal acceleration,
transverse acceleration and yaw rate senders are calibrated.

30

Steering system
Overview
The Q3 uses an electromechanical power steering system
similar to that used in the A7 Sportback. When compared
to conventional hydraulically boosted steering systems, the
electromechanical system reduces fuel consumption and
provides greater potential for optional equipment.

Mechanically adjustable steering column.
(approximately 2 in [50 mm] of vertical and
horizontal adjustment)

602_057

Electromechanical steering system with
axial parallel drive

31

Electromechanical steering
Overview
The compact unit consists of the actual steering gear, an
electric motor for power assistance, a control module, a
sensor for measuring steering torque and a sensor for
monitoring the position of the electric motor rotor.

Electromechanical Power
Steering Motor V187

Rack and pinion steering gear

Steering Torque Sensor G269

Power Steering Control Module J500

602_058

Recirculating ball nut

Drive
V187 is powered directly by Power Steering Control
Module J500.
The rotational movement of the motor is converted to the
linear movement of the steering rack by a recirculating ball
nut assembly. The ball nut is driven by a toothed belt.
The current intensity with which the motor is activated
regulates the amount of assist of the steering torque.

602_059

Electromechanical Power
Steering Motor V187

Toothed belt

Reference

For detailed information about the general design and function of the steering gear, refer to eSelf-Study
Program 990303, The 2012 Audi A7 Running Gear and Suspension Systems.
32

The recirculating ball nut is fixed in a longitudinal direction.
If it is turned, there is a linear movement of the spindle in
the direction of the arrow.

Direction of rotation of the
recirculating ball nut

Linear movement of the
spindle/rack

To restrict the contact among the ball bearings, “ball
circuits” that are as short as possible are used. This is why
the ball nut has individual circuits.

Rotation direction of the
recirculating ball nut

602_060

Ball race

Return channel

Recirculating ball nut

602_061

Linear movement of
the spindle/rack

Steering Torque Sensor G289
Steering torque is measured by Steering Torque Sensor G289.
The steering input shaft and steering pinion are
interconnected by a torsion bar. Turning the steering wheel
results in minimal rotation of the torsion bar and also the
input shaft relative to the steering pinion. The angle of
rotation is measured by the the sensor and is a direct
measure of steering torque.

Steering input
shaft

Steering Torque
Sensor G289

Steering pinion

602_062

33

Electromechanical Power Steering Motor V187
Toothed belt drive
pinion

The Audi Q3 uses a permanently excited three-phase AC
synchronous motor for steering assistance. This motor
concept was chosen on the basis of the following key
advantages:

• Synchronous motors are noted for their compact design
and high performance.

• Permanent excitation eliminates the need for slip rings
for transmitting the exciter current to the rotor.

The necessary phase voltages are calculated by the Power
Steering Control Module and applied through the power
output stages.
The stator has nine field coils arranged in groups of three
and connected in series. They are energized by a sine-wave
current. The three electric currents are phase offset
relative to one another. The three magnetic fields
generated produce a rotating magnetic field which induces
a synchronous rotational movement in the rotor.

Rotor position sensor

The rotor has six permanent magnets alternately arranged
in a north/south direction. For smoother running, the six
pole ring magnet is magnetized at an angle.

Stator

Rotor

602_063

Receiver coils

Rotor disc

Rotor position detection
The rotor position sensor monitors the position of the
rotor. The control module must know the exact position of
the rotor to be able to calculate the phase voltages
required for the rotating magnetic field (electronic sensor
controlled commutation). The measured value of the rotor
position sensor is also utilized to define the steering stops.
To avoid hard mechanical stops, "soft" limits stops are
implemented by the electromechanical steering system.

The exciter coil is supplied with a sine-wave exciter voltage.
The alternating magnetic field which develops around the
exciter coil acts upon the rotor disc. The rotor disc conducts
the magnetic flux of the alternating magnetic field
generated by the exciter coil to the receiver coils. This
induces in the receiver coils an alternating voltage which is
phase offset proportional to the position of the rotor disc
relative to the exciter voltage.

602_064

Exciter coil

34

General functional principle
When the steering wheel starts to turn, the torsion bar
connecting the steering input shaft to the steering pinion is
rotated. This rotation is measured by the steering torque
sensor and sent to the control module. At the same time,