eSelf Study Program 960143

The 2015 Audi A3
Running Gear and Suspension System

Audi of America, LLC
Service Training
Created in the U.S.A.
Created 11/2013
Course Number 960143
©2013 Audi of America, LLC
All rights reserved. Information contained in this manual is based on
the latest information available at the time of printing and is subject to
the copyright and other intellectual property rights of Audi of America,
LLC., its affiliated companies and its licensors. All rights are reserved
to make changes at any time without notice. No part of this document
may be reproduced, stored in a retrieval system, or transmitted in any
form or by any means, electronic, mechanical, photocopying, recording
or otherwise, nor may these materials be modified or reposted to other
sites without the prior expressed written permission of the publisher.
All requests for permission to copy and redistribute information should
be referred to Audi of America, LLC.
Always check Technical Bulletins and the latest electronic service repair
literature for information that may supersede any information included
in this booklet.

Revision 2: 12/2013
3

Contents
Suspension system - overall concept...................................................6
Suspension..........................................................................................7
Overview ..................................................................................................................................................................... 7

Axles and suspension alignment.........................................................8
Front suspension ....................................................................................................................................................... 8
Four-link rear suspension ......................................................................................................................................... 9
Suspension alignment and set-up ..........................................................................................................................10

Brake system.................................................................................... 12
Overview ....................................................................................................................................................................12
Design and function .................................................................................................................................................16
Service operations ....................................................................................................................................................17
ESP overview .............................................................................................................................................................18
System components .................................................................................................................................................18
Service operations ....................................................................................................................................................20

Steering system................................................................................ 21
Overview ....................................................................................................................................................................21
Electro-mechanical steering ....................................................................................................................................21

Audi magnetic ride........................................................................... 24
Overview ....................................................................................................................................................................24
Service operations ....................................................................................................................................................27

Adaptive cruise control (ACC)........................................................... 28
Overview ....................................................................................................................................................................28
Design and function .................................................................................................................................................28
Operation and driver information ...........................................................................................................................28
Service and diagnostic operations ..........................................................................................................................28

Wheels and tires............................................................................... 29
Overview ....................................................................................................................................................................29
Tire Pressure Monitoring System ............................................................................................................................30

eSelf Study Program......................................................................... 31
Knowledge Assessment................................................................... 32

4

This eSelf Study Program teaches a basic knowledge of the design and functions of new models,
new automotive components or technologies.
It is not a Repair Manual! All values given are intended as a guideline only.
For maintenance and repair work, always refer to the current technical literature.

Note

Reference

Suspension system - overall concept
A major developmental goal for the suspension system of
the Audi A3 was to achieve a high level of agility, sporty
handling and high driving comfort without making any
compromises to driving dynamics.
Even it its basic configuration, the 2015 A3 affords a brandtypical driving experience and comfort with a strong
emphasis on sporty attributes. The A3 offers a high level of
driving enjoyment.
This has been accomplished by using the proven concept of
the MacPherson front suspension in combination with
newly developed torsion beam and four link rear suspensions. The torsion beam version of the rear suspension is
33 lb (15 kg) lighter than an equivalent multi-link rear
suspension in addition to having aerodynamic advantages.
The use of the torsion beam rear suspension or the fourlink suspension is dependent on engine horsepower output.

A reduced weight electro-mechanical power steering
system with speed dependent assistance (Servotronic) is
standard equipment on the A3.
A variable steering ratio is achieved through the special
geometry of the rack and pinion system. A range of newly
developed steering wheels extends from the conventional
four-spoke wheel to the three-spoke multi-function sport
steering wheel with leather trim and shift paddles.
The 15 and 16 inch service brakes (engine dependent) are
larger than those of the predecessor model and provide
excellent braking capability relative to engine power
output. A newly developed Continental Mk100 ESP system
is being used for the first time by Audi.

The A3 will also be available with all wheel drive in combination with the four-link rear suspension. An electronic
damping control system based on the established Audi
magnetic ride system will also be available as an option.

612_001a

6

Suspension
Overview
The following suspension system versions will be offered
for the 2015 A3 sedan:

Dynamic suspension
The dynamic suspension system is standard in the 2015
Audi A3.
612_002a

Sports suspension
The sports suspension is optional. In models with sports
suspension, ride height is 0.59 in (15 mm) lower than in
models with the standard suspension. The S3 model will
have its own version of the sport suspension featuring
more sporty characteristics.

612_002b

Suspension system with electronic
damping control
This suspension system is currently available only on S3
models. It is based on the Audi magnetic ride system
currently used in other Audi models.
612_002c

Components of the 2015 Audi A3 suspension systems are
also used by other Group brands. The production control
numbers denoting the suspension type therefore deviate
from those of suspension systems used exclusively by Audi.

7

The production control numbers (PR numbers) are
explained in the repair manual (ElsaWeb or ElsaPro). Under
Repair Group 44 "Wheels, tires and suspension alignment".

Axles and suspension alignment
Front suspension
A newly developed MacPherson strut front suspension is
used on the 2015 A3. The kinematics give the vehicle sporty
and dynamic qualities; agile handling, roll comfort, reduced
vibration, low roll angle and good dynamic stability.

Spring
−− Steel spring with linear
characteristic

Shock absorber
−− Twin-tube shock absorber with
additional polyurethane spring

Steering forces are transmitted directly to the swivel bearings to provide immediate steering response.

Anti-roll bar
−− Tubular anti-roll bars

Swivel bearing
−− Two versions are available
depending on engine output
−− 15“ wheels, steel swivel bearing
−− 16/17“ wheels, aluminium swivel
bearing

612_003

Joint
−− Ball joint for connecting the wishbone and swivel
bearing

Engine/transmission mount
−− Aluminium casting

Wishbone
−− One-piece stamped
steel design

Wheel bearing / wheel hub
−− Third generation wheel
bearing with integrated wheel
hub

8

Rear suspension
Torsion beam suspension
A newly developed torsion beam suspension system is used
for front wheel drive models with the 2.0L TDI engine. This
axle is used to accommodate the AdBlue tank necessary for
the Diesel fuel system. Torsion is produced by a downwardfacing U profile. Due to the axle design, there is no need for
an anti-roll bar.

Shock absorber
−− Twin-tube shock absorber
with additional polyurethane
spring

The axle locating bearings are highly rigid in the vehicle’s
transverse direction to ensure a rapid build-up of lateral
traction.
Because the shock absorbers are in approximately the same
position as in the multi-link rear suspension versions, only
minor bodyshell modifications were required.

Steel springs
−− Steel spring with
linear characteristic

Wheel bearings
−− Third generation wheel bearing
with integrated wheel hub
−− Bolted to the axle

612_004

Bearing pedestal
−− Stamped steel part
−− Supports the rear axle at
the bearing and is bolted
to the vehicle body

9

Torsion beam suspension
−− Made of welded steel
components

Bearing
−− Rubber-metal bearing

Four-link rear suspension
A four-link suspension for quattro and front wheel drive is
used on vehicles with engine outputs of 114 hp (85 kW)
and higher. This suspension will be standard equipment for
gasoline powered vehicles in the North American region.
The basis for the new development is the proven rear suspension from the predecessor model. The shock absorbers
are now coupled to the spring link instead of to the wheel
carrier. The anti-roll bars are also connected to the spring
link.

Shock absorber
−− Twin-tube shock absorber
with additional polyurethane spring

Steel springs
−− Steel springs with
linear characteristic

Spring travel has been increased in order to enhance
comfort. The repositioning of the upper damper bearings
has allowed the fuel tank filler design to be optimized. The
weight of the axle has been significantly reduced by
approximately 10 lb (4.5 kg) when compared to the predecessor model.

Anti-roll bar
−− Tubular anti-roll
bars

Tie rod
−− Plastic component

Spring link
−− Made of hightensile steel

Wheel bearing / wheel hub
−− Third generation wheel bearing
with integrated wheel hub
−− Adopted from predecessor
model for front wheel drive
−− New part for quattro drive

Upper track control arm
−− Made of steel

612_005

Trailing arm
−− Stamped steel
part

Wheel carrier
−− Steel casting for
front wheel drive
−− Aluminium casting for
quattro drive

Rear sub-frame
−− Made of steel

Bearing pedestal
−− Stamped steel
part

Bearing
−− Rubber metal bearing

Track link
−− Made of steel

10

Suspension alignment and set-up
The left and right toe-in angles on the front axle can be
adjusted separately by changing the length of the track
rods. The camber can be balanced (centered) within narrow
limits by moving the sub-frame transversely.

Individual toe and camber angles can be adjusted on the
four-link rear suspension. There are no adjustments on the
torsion beam rear suspension.

Toe adjustment at the spring link/subframe attachment point (not shown).

Toe adjustment

Camber adjustment

612_006

11

Brake system
Overview
The brake system of the 2015 A3 is a logical progression of
its predecessor. It is the first Audi to be equipped with the
Continental ESP MK100 brake system. At the start of
production, 15 inch and 16 inch systems will be used
depending on engine output. Around mid-year, 2014 the
Audi S3 will come standard with 17 inch brakes. Pistons
with larger diameters than those of the predecessor model
are used on all models.

The electro-mechanical parking brake (EPB) is now used on
the 2015 A3. The brake servo and pedal assembly are
newly designed.

ESP MK 100 by Continental

612_001a

15”, 16” or 17”
brakes

Tandem master brake cylinder
with single 10“ or 11“ brake servo

15" or 17” rear wheel brakes with
electro-mechanical parking brake
(EPB)

12

Front wheel brakes
Engine type

R4 2.0 TDI 150 hp (111 kW)

R4 1.8 TFSI 170 hp (125 kW)
R4 2.0 TFSI 220 hp (162 kW)

R4 2.0 TFSI 285 hp (206 kW)

Minimum wheel size

15“

16“

17“

Brake type

PC57-25/14 15“
TRW

PC57-25/14 16“
TRW

C60-30/13 17“
TRW

Number of pistons

1

1

1

Piston diameter

2.24 in (57 mm)

2.24 in (57 mm)

2.36 in (60 mm)

Brake disc diameter

11.33 in (288 mm)

12.28 in (312 mm)

13.38 in (340 mm)

612_027

13

Rear wheel brakes
Engine type

R4 1.8 TFSI 170 hp (125 kW)
R4 2.0 TDI 150 hp (112 kW)

R4 2.0 TFSI 220 hp (162 kW)
R4 2.0 TFSI 285 hp (210kW)

Minimum wheel size

15“

17“

Brake type

FNc-M38-1510 TMD
Continental

FNc-M42-1722 TMD
Continental

Number of pistons

1

1

Piston diameter

1.49 in (38 mm)

1.65 in (42 mm)

Brake disc diameter

10.70 in (272 mm)

12.20 in (310 mm)

612_028

14

Brake servo, master brake cylinder,
pedal assembly