Technical Service Bulletin
47 Hard brake pedal while attempting to start the vehicle
47 23 25 2055646/5 November 22, 2023. Supersedes Technical Service Bulletin Group 47 number 22-16 dated
August 11, 2022 for reasons listed below.
Model(s)

Year

Q7

2017 – 2023

A4, and A4
allroad

2017 – 2021

S4, A5, A6
Cabriolet, A5
Sportback, S5,
S5 Cabriolet, S5
Sportback, Q5,
and SQ5

2018 – 2021

VIN Range

Vehicle-Specific Equipment

All

Not Applicable

2018 – 2019

RS 5

2021
2019

RS 5 Sportback

2021

Q8

2019 – 2023

Q5 e quattro

2020 – 2021

SQ7, SQ8, and
RS Q8

2020 – 2023

A6, A6 allroad,
S6, RS 6 Avant,
A7, A7 e quattro,
S7, RS 7, Q5
Sportback, and
SQ5 Sportback

2021

Condition
REVISION HISTORY
Revision

Date

Purpose

5

-

Revised header (Updated Model Year)
Revised Warranty (Updated table)

4

08/11/2023

Revised header (Added Model Years)
Revised Service (Updated procedure)

© 2023 Audi of America, Inc.
Internal

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All rights reserved. Information contained in this document 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, Inc., 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.

Technical Service Bulletin
3

06/09/2022

Revised Warranty (Updated table)

Customer states:
• After a short stationary period, the vehicle sporadically does not start and there is a hard brake pedal concern.

Technical Background
Due to dirt particles in the non-return valve in the vacuum hose for the brake servo, the vacuum in the brake servo
cannot be held on a parked vehicle.
When starting the vehicle the usual brake force is not enough to get the start authorization of the brake light
switch.
Normally, a vacuum of 600 to 950 mbar is reached.
Depending on the parking position (slope) or the user behavior the vehicle is parked with a small vacuum within
12 hours the vacuum may drop by up to 400 mbar.

Production Solution
Not applicable.

Service
Proceed as follows:
• Check the following components for possible damages: vacuum hose; sensor G608; connectors, seals, valves.
• Check for leaks according to Elsa >> Brake System >> 47 Hydraulic Components >> Vacuum System.
• Check for small cracks in the vacuum hose or in the connection points between check valves.
• If damages/cracks/leaks are found: Replace the necessary components according to: Elsa Repair Manual,
Elsa >> Brake System >> 47 Hydraulic Components >> Vacuum System.

Warranty
Claim Type:

• 110 up to 48 Months/50,000 Miles.
• G10 for CPO Covered Vehicles – Verify Owner.
• If the vehicle is outside any warranty, this Technical Service Bulletin is
informational only.

Service Number:

4777

Damage Code:

0010

Labor Operations:

Vacuum hose remove + reinstall

© 2023 Audi of America, Inc.
Internal

4777 1999

10 TU

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All rights reserved. Information contained in this document 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, Inc., 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.

Technical Service Bulletin

Diagnostic Time:

Claim Comment:

Brace remove + reinstall (Only if installed in 4086 1999
the vehicle)

50 TU

Cowl panel trim remove + reinstall

6644 19XX

See SRT with
associated
operations

GFF

No allowance

0 TU

Road test prior to the service procedure

No allowance

0 TU

Road test after the service procedure

No allowance

0 TU

As per TSB 2055646/5

All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures
Manual. Claims are subject to review or audit by Audi Warranty.

Required Parts and Tools
Part Number Part Description

Quantity

See ETKA

Vacuum hose with non-return valve and pressure sensor

01

See ETKA

Fasteners, Bolts, Nuts, and Screws as needed per the Repair Manual

See ETKA/ELSA

Additional Information
More information on this system can be found in the following resources:
• Elsa: Brake System >> 47 Hydraulic Components >> Vacuum System.
All parts and service references provided in this TSB (2055646) are subject to change and/or removal.
©2023 Audi of America, Inc. All rights reserved. The information contained in this document 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, Inc., 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.

© 2023 Audi of America, Inc.
Internal

Page 3 of 3

All rights reserved. Information contained in this document 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, Inc., 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.