TSB_2078039_2 Service Bulletin/Repair Instructions

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Technical Service Bulletin Transaction No.: 2078039/2
90 Warning message about high-voltage electrical system; U014600, U112100,
041200 Release date: Jan 14, 2026
Condition
Model(s) Year(s) VIN Range Vehicle Specific Equipment
A6 Sportback e-tron,

S6 Sportback e-tron,

Q6 e-tron, Q6

Sportback e-tron,

$Q6 e-tron, and SQ6

Sportback e-tron
2025 All Not applicable
REVISION HISTORY
Revision |Date Purpose
2 - Revised Condition (Added model table)

Revised Service (updated repair to KD2)

Revised Warranty (Updated warranty table)
1 05/22/2025 | Initial publication
Customer states:
At the start of a trip, the warning “High-voltage electrical system: fault. Please contact workshop” (Figure 1) appears

in the instrument cluster. The drive system is not activated. The remaining range is displayed as 0 miles (0 km).
* The concern is sporadic. After switching off the ignition and waiting for several minutes (bus sleep), the

concern is remedied.
ee et

ee Rela
erty S|

abr ecly

Lage
Figure 1. The above message appears at the start of the trip in the instrument cluster.
Workshop findings:
Corresponding DTCs are stored (passive/intermittent) in several control units at the time when the fault occurred.
Module address Module description DTC description
008C Hybrid battery U014600 Lost communication with Serial Data Gateway Module

management “A”
00C5 Thermal Management |U014600: Lost communication with Serial Data Gateway Module
"A”
8133 Low-voltage power U112100: Databus missing message

distribution 1
812C Drive and chassis main | U014600: Lost communication with Serial Data Gateway Module

control module "A"
0044 Power steering U112100: Databus missing message
0019 Data bus OBD U041200: Invalid Data Received From Battery Energy Control

interface Module “A”
0017 Instrument cluster U112100 Data bus missing message
If the complaint is active during the workshop visit, the drive system can be activated by performing a bus

sleep cycle. A bus sleep cycle can be achieved by locking the vehicle, and then waiting for five minutes, for
example.
Technical Background
Software issue.
Production Solution

Optimized software from week 12/2025.
Service
This TSB replaces PSS 2076787, 90 PSS Warning message about high-voltage electrical system; U014600,
U112100, U041200.
To permanently rectify the fault, please perform the software update described in TSB 2079690 00 Combined

software update 03.10.00/C (28.13.01) KD2.
Warranty
Claim Type:
¢ — If the vehicle is outside of any warranty, this Technical Service Bulletin is
informational only.
Service Number:
9035
Damage Code:
KDO2
Labor Operations:
Software update, including connecting battery
charger
0151 0010 See SRT with
associated
operations
Fixed rate for software update, including all 0151 0040 130 TU

required preliminary and follow-up work (including

bus sleep cycle, calibration drives, and additional

work)
In the case of additional attempts after flash abort |0150 9999 50 TU

occurred, an additional lump sum of 50 time units
can be claimed per flash cancellation Per each
documented attempt
Claim Comment: As per TSB 2078039/2
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.
When performing the combined software update, time stamps are not required for billing under warranty. You are

therefore permitted to work on other vehicles at the same time. The combined software update can also be

performed by non-productive personnel.
Additional Information
The following Technical Service Bulletin(s) will be necessary to complete this procedure:

* TSB 2079690, 00 Combined software update 03.10.00/C (28.13.01) KD2
All part and service references provided in this TSB (2078039) 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.
©2026 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.

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