Technical Service Bulletin
64 Warning instrument cluster: "Child lock: fault" w/ B177901: Function Lighting Child Safety Electrical
Error
64 24 00 2074791/1 August 8, 2024.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

Q4 e-tron, and
Q4 Sportback etron

2022

All

Not Applicable

Condition
Customer states:
The message “Child lock: fault” is displayed in the instrument cluster.

Workshop findings:
The customer complaint is confirmed. The following DTC is logged in the Driver’s Door Electronics control
unit -J386 (diagnostic address 0042):
B177901: Function lighting child safety electrical error

Technical Background 1
Optimized target data container for the Driver’s Door Electronics control unit, J386 (diagnostic address 0042).

Production Solution
Not applicable.

Service
First, check whether there are any service campaigns for the vehicle that have not yet been completed
and carry them out.

© 2024 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
To prevent charging of the high-voltage battery during the software update, the high-voltage cable is
to be removed BEFORE entry of the SVM code on vehicles with high-voltage components. Charging
the high-voltage battery during a software update can damage the high-voltage components.

The flashing procedure may be performed using either a USB cable or a point-to-point Wi-Fi
connection with adequate reception. We strongly recommend flashing using a USB cable. This
ensures that data transmission is as reliable as possible. If you wish to perform flashing in Wi-Fi
mode, please ensure that you are using a point-to-point connection. Infrastructure mode is not
permissible as it is very prone to interference/errors. If the Wi-Fi reception is insufficient, a message
will appear, and the USB cable must be used. Bluetooth connections are not permitted. Remove
diagnosis head from diagnostic socket to connect USB cable. If the USB cable is plugged in while the
diagnostic head is connected, the communication still takes place via Bluetooth.

Performing update:

TIP: Prior to performing the SVM update, fully open and close all electric windows via the window
regulator switches immediately BEFORE using the SVM code. This ensures that all of the door control
modules are “awake” for the update.
Follow all instructions in TSB 2011732: 00 Software Version Management (SVM), operating instructions.
•

Perform the function “SVM – control module configuration” in the driver door control unit (diagnostic
address 0042). This will give the control unit the latest target data container.

Once completed successfully, perform basic setting of the window regulator for the driver door.

Warranty
Claim Type:

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

Service Number:

© 2024 Audi of America, Inc.
Internal

6438

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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
Damage Code:

0039

Labor Operations:

Software Update

0151 00xx

Time stated on
the diagnostic
protocol

Charge Battery

2706 8950

See SRT with
associated
operations

Claim Comment:

As per TSB 2074791/1

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 (2074791) 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
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.