Technical Service Bulletin
94 Exterior lights, moisture accumulation
94 12 92 2012749/11 October 24, 2012. Supersedes Technical Service Bulletin Group 94 number 11-52 dated
October 11, 2011 for reasons listed below.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

All

1996-2013

All

Not Applicable

Condition
REVISION HISTORY
Revision

Date

Purpose

11

-

Revised Service (Added Q7 specific TSB)

10

10/5/2011

Revised header data (Added new A6)

9

7/11/2011

Revised header data (Added model A7)

8

5/25/2011

Revised header data (Added model years)

7

11/18/2008

Revised Title to include Repair Group

Condensation is visible on the inside of the headlight, taillight, fog light, side marker light, front turn signal,
daytime running lights, or third brake light lens.

Technical Background
Damp air settles on the inside of a cold lens, which creates condensation.
The headlight circulation system allows air from the outside to flow through the headlights. This open waterprotected ventilation system (needed for pressure compensation) creates different climate zones in the headlight:
very warm areas, where the lens is warmed up by the light, and relatively cool areas, where the lens is cooled
down by the air flow.
Considerable differences in humidity and temperature between the inside and the outside of the headlights, even
while driving, can lead to condensation. This is especially true in cold and wet weather, but it can also happen
after a car wash, after steam cleaning the engine or the front end, with overnight temperature changes, etc. This

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© 2012 Audi of America, Inc.
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
phenomenon is more visible on lenses made of clear glass than on lenses with patterns. The moisture does not
affect the headlight function (light performance) and does not lead to corrosion or other damage to headlight
parts.

Production Solution
Not applicable.

Service
For headlights, the affected lens surface should be clear after approximately 10 minutes of light operation,
although the entire lens surface may not clear. The clearing process depends on the outside temperature and the
humidity.
In cases where water droplets have formed on the inside of the lens or water has collected at the bottom of the
light assembly, check for leaking seals and/or cracks in the lens or light assembly. If no damage is found, use
compressed air (less than 30 PSI) to clear the lens.
On light assemblies with LED lights, e.g. S6 daytime running lights, the LED lights do not emit enough heat to
clear the moisture from the lens. Only the pressure difference of the ventilation system provides the air flow to
clear the moisture on the inside of the lens. The design of the ventilation system on these types of lights will
ensure the lens is clear after a few miles have been driven.
For Audi Q7, please see TSB 2028277 94 Moisture accumulation in headlamps for the installation of headlight
ventilation valves. Do not replace light or lens assemblies for these conditions.

Warranty
This TSB is informational only and not applicable to any Audi warranty.

Additional Information
All part and service references provided in this TSB are subject to change and/or removal. Always check with
your Parts Dept. and service manuals for the latest information.

Page 2 of 2
© 2012 Audi of America, Inc.
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.