Technical Service Bulletin
94 Warning in instrument cluster relating to exterior lighting/Audi adaptive light DTC: B126A29, U112100,
U110B00
94 24 84 2074942/1 August 29, 2024.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

Q3

2022 - 2024

All

Not Applicable

Condition
Customer states:
•

A warning lamp for the exterior lighting or Audi adaptive light is displayed in the instrument cluster. No
fault is apparent in the lighting system.

Workshop findings:
The complaint can be reproduced. The following DTCs are stored in the onboard supply control unit J519
(diagnostic address 0009):
•

B126A29 Light switch; implausible signal.

•

U112100 Data bus missing message.

•

U110B00 Light switch no communication.

All lighting functions are working.

Technical Background 1
Software issue.

Production Solution
Optimized software for model year 2025.

© 2024 Audi of America, Inc.
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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
Service
Check whether the situation is as described above. This phenomenon occurs very occasionally. Pressing the
“AUTO” button will cause the warning lamp to go out and the DTCs to change to intermittent. The DTCs can
then be erased.
If only DTC “U110B00 Light switch no communication” is stored without the others, the cause may be a
loose connector, a pin that has been pushed back or a wiring problem.

Warranty
Claim Type:

•

If the vehicle is outside of any warranty, this Technical Service Bulletin
is informational only.

Service Number:

9405

Damage Code:

0040

Labor Operations:

GFF / Guided Functions

0150 0010

See SRT with
associated operations

GFF / Guided Functions

0150 0060

Time stated on the
diagnostic protocol

Claim Comment:

As per TSB 2074942/1

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.

Additional Information
All part and service references provided in this TSB (2074942) are subject to change and/or removal. Always
check with your Parts Department and/or ETKA for the latest information and parts bulletins. Please check
the Repair Manual for fasteners, bolts, nuts, and screws that require replacement during the repair.
©2024 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
© 2024 Audi of America, Inc.
Internal

Page 2 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.

Technical Service Bulletin
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.

© 2024 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.