91 SOS Emergency call function deactivated message in the cluster, DTC U153E00 is stored in the
telematics module
91 21 36 2055945/7 September 22, 2021. Supersedes Technical Service Bulletin Group 91 number 21-29 dated
September 7, 2021 for reasons listed below.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

A4, A4
allroad, S4,
A5, A5
Cabriolet,
A5
sportback,
S5, S5
Cabriolet,
S5
sportback,
RS 5, and
RS 5
Cabriolet

2019

All

ConBox Low

A6 allroad,
RS 7, SQ8,
RS Q8, and
Audi e-tron
sportback

2020

All

ConBox Low

A6, A7, A8,
S6, S7, S8,
Q5, Q7, Q8,
SQ5, SQ7,
and Audi etron quattro

2019 - 2020

All

ConBox Low

Condition
REVISION HISTORY
Revision

Date

Purpose

7

-

Revised Service (Updated Steps in Scenario 1 and 3)

6

09/07/2021

Revised header (Updated Elsa display)
Revised Service (Added clear DTC instructions to Scenario 3)
Revised Warranty (Updated Labor Operations)

5

10/19/2020

Revised Technical Background (Added information for high occurrence)
Revised Service (Added service solution for high occurrence)
Revised Required Parts and Tools (Added table)

Page 1 of 7
© 2021 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.

Customer states:
 The warning message “SOS Emergency call
function deactivated” is seen in the instrument
cluster (Figure 1 or 2).

Figure 1. SOS warning in the instrument cluster.

Figure 2. SOS warning in the instrument cluster.

Technical Background
The warning message is generated by the telematics control module (ConBox Low for MY19), J949 (address
word 0075) and is primarily seen in two different scenarios:
 When there is a hardware or software malfunction of the control module.
 When there is a problem connecting to the Mobile Network Operator (AT&T).
For problems related to the cellular network (MNO), the following DTC may be found in in the telematics control
module, J949 (address word 0075):
 DTC U153E00 (Emergency call module and communication unit Recognition in mobile communications
network not possible).
This DTC will trigger the warning message in the cluster immediately when the signal to the MNO (AT&T) is
lost. However, depending on how long of a period the signal loss occurs, the vehicle may require a full sleep cycle

Page 2 of 7
© 2021 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.

in order for the DTC to change to sporadic. The warning message in the cluster will only turn off when the DTC
changes to sporadic.
Example Customer Scenarios:
 When a customer is on a long drive through an area where AT&T has little-to-no service, the warning message
can occur. If the customer drives the vehicle for 15-30 minutes with no service, then the vehicle may take a full
hour before it retries to connect to the AT&T network. This is a requirement of AT&T. When the customer
drives the vehicle back into an area of service, the SOS light may stay off, or red, until the vehicle has been in
a service area for up to one hour, or until the vehicle is turned off long enough for the vehicle systems to go
through a sleep cycle.
 If the customer operates the vehicle continuously in an area with no service, then each time the vehicle starts
the warning message will be present. This is true of when the vehicle is operated outside of the United States
of America (Canada, Mexico, or overseas) since there are no supported cellular service providers in these
areas.
 For certain MY20 vehicles, the telematics control module changes to a new ConBox High system. This new
system will be updated so that the warning message is not seen or heard in the above two scenarios. Instead,
the customer will need to rely on the SOS button LED status to understand if the system is functioning
normally.
 A service solution is available for vehicles with a high occurrence of the instrument cluster message.
A general service solution is being prepared.

Production Solution
Certain models for MY20 with ConBox High will receive new hardware and software that resolves this concern. All
MY21 vehicles will receive the solution with the ConBox High integration in series production.

Service
Scenario 1: If the DTC is sporadic:
1.

Please note the time and date when the DTC set and document it in the repair order in the event
the car returns for a repeat repair.

2.

In some cases, if the LED is not green, it might be necessary to clear the vehicle’s DTCs

3.

If the SOS button LED is green, then tell the customer that this warning is normal and is shown
whenever the vehicle is driven in an area with little-to-no LTE service with AT&T.

4.

No further analysis is required.

Page 3 of 7
© 2021 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.

Scenario 2:

If the DTC is static and the warning message does not go away after a bus sleep cycle:

1.

Follow the recommended troubleshooting steps provided by GFF for all other DTCs.

2.

Ignore the recommendation to replace the hardware if recommended by GFF unless there is a DTC for
“Control Module Faulty”, only then should the hardware be replaced.

3.

If the SOS button LED is red or off, then gain access to the telematics control module, J949 (address word
0075) (see Elsa).

4.

Move the vehicle outside where it can get a full view of the sky for better cellular reception.

5.

With the ignition off, remove the backup battery from the module and disconnect the main connector from
the telematics control module, J949 (address word 0075).

6.

Let the vehicle sit for 2-3 minutes.

7.

Insert the backup battery into the telematics control module and reconnect the connector.

8.

Turn the ignition on and let the vehicle sit for 5-10 minutes to allow the GPS system to gain a full 3D lock on
the vehicle’s position. A GPS lock is required for the system to activate with the Audi connect backend.

9.

Check for the SOS button LED to be green. In some cases, clearing the vehicle’s DTCs is required if the
LED is not green at this point.
If the LED is still not green then check with someone at the dealership that has AT&T mobile service and
see if the LTE reception in the area is poor or if the cell phone is not able to access the internet or make
calls using AT&T’s LTE service (try accessing a web page or YouTube on the phone). It is important to note
that in some cases, it is possible the phone can show multiple bars of service but cannot make a call or
receive data. This happens when the network is overloaded or there is an issue with the MNO.

10. If there is no issue with AT&T mobile reception on a cell phone then open a TAC contact for further
assistance. Do not replace any hardware until consulting with TAC.

Scenario 3: If DTC U153E00’s Frequency Counter is greater than 5 (Figure 3):

Page 4 of 7
© 2021 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.

Figure 3. Frequency counter in diagnostics log.
1.

Replace the telematics control module (ConBox High), J949 (address word 0075) with part
number 992035286C.

2.

Upload the initial diagnostics log showing the vehicle is eligible for the parts replacement to GFF
Paperless and include the GFF Paperless ID in the warranty claim comments.
Note:
The telematics control module (ConBox High) may only be replaced if DTC U153E00’s Frequency
Counter is greater than 5. Claims that do not meet this criteria for replaced parts will be subject to
review.

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:

9170

Damage Code:

0010

Labor Operations:

If only the battery has been removed and reinstalled:

Page 5 of 7
© 2021 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.

Onboard computer ECM backup battery
replace

9178 5500

See SRT with
associated
operations

Telematics control module remove + reinstall

9170 19XX

See SRT with
associated
operations

GFF

0150 0000

Time stated on
the diagnostic
protocol (Max
50 TU)

Road test prior to the service procedure

No allowance

0 TU

Road test after the service procedure

No allowance

0 TU

If the control module has been replaced:

Diagnostic Time:

Claim Comment:

As per TSB #2055945/7

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
The part numbers mentioned in this TSB are different than the ones listed in ETKA. Only use parts listed in this
TSB, this includes superseding part numbers!
Part Number

Part Description

Quantity

992035286C

Telematics Control Module

01 (High occurrence only)

Additional Information
All part and service references provided in this TSB (2055945) 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.
©2021 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

Page 6 of 7
© 2021 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.

these materials be modified or reposted to other sites, without the prior expressed written permission of the
publisher.

Page 7 of 7
© 2021 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.