80 The interior vehicle heating is insufficient and the engine coolant is discolored
80 21 11 2062583/1 March 19, 2021.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

All

2012 - 2021

All

Not Applicable

Condition
Customer states:
 Insufficient or uneven cabin heating performance from the HVAC system. The cabin heating may be slow to
get warm.

Technical Background
The symptom can easily be duplicated. The engine coolant may contain contaminants that are visually apparent.
These contaminants can obstruct the coolant flow through the heater core and diminish the cabin heating
capability of the HVAC system.

Production Solution
There has been a change in the coolant standard to G12 evo.

Service
Diagnosis will reveal a drastic temperature difference between the inlet and outlet heater hoses to the heater
core with the inlet being warmer than the outlet suggesting an obstruction in the heater core.

Warning:
Risk of scalding due to hot coolant. The cooling system is under pressure when the engine is warm. Risk of
scalding due to hot steam and hot coolant.

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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.

While there may be any number of causes for insufficient cabin heating, the subject matter covered in this TSB
addresses only one possible cause. Should the symptom profile be inconsistent with the root cause described in
this TSB continue diagnosis to find an alternative cause.
1.

Examples of what the appearance of the
discoloration of both the coolant as well as the
coolant reservoir (Figures 1 – 4). This coolant
contamination is not engine oil or transmission
fluid.

Figure 1. Suspended particulate matter.
2.

Figure 2. ‘Brownish” discoloration.

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© 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.

3.

Figure 3. Discoloration on the inside of the coolant
reservoir.
4.

Figure 4. Particulate matter.

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© 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.

5.

Clean and flush the cooling system using cooling
system cleaning set, part number G 052 525 A3 as
follows (Figure 5):

Figure 5. Cooling system cleaning set.
6.

Drain coolant when the engine is warm and the
coolant thermostat is open according to the
procedure in ElsaPro (Figure 6).

Figure 6. Drain the coolant.

Page 4 of 11
© 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.

7.

Flush the heat exchanger(s) with water in the
opposite flow direction. Do not exceed 2 bar of
water pressure (Figure 7).

Figure 7. Heater core connections.
8.

Blow the coolant out of the heat exchanger(s) in
the opposite flow direction (Figure 8).

Figure 8. Blowing out heater core.

Page 5 of 11
© 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.

9.

Add 3.0 liters of cooling system cleaner ‘S’ and the
balance of the fill with coolant (Figure 9). Perform
bleeding procedure. Run the engine for 90 minutes
with this mixture with the cabin heating on full hot
and HI fan. If equipped, also set the rear HVAC
unit to full hot and HI fan.

Figure 9. Cooling system cleaner ‘S’.
10. Drain the cleaning solution.
11. Add 3.0 liters of neutralizer ‘S’ and the balance of
the fill with coolant. Perform bleeding procedure
(Figure 10). Run the engine for 15 minutes with
this mixture with the cabin heating on full hot and
HI fan. If equipped, also set the rear HVAC unit to
full hot and HI fan.

Figure 10. Neutralizer ‘S’.
12. Drain the neutralizer solution.

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© 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.

13. Fill the cooling system with plain distilled water
(Figure 11). Perform bleeding procedure. Again,
set the cabin heating to full hot and HI fan. If
equipped, also set the rear HVAC unit to full hot
and HI fan. Run the engine at approximately 2000
rpm until the cooling fans activate. Continue to run
the engine at this speed for an additional 3
minutes.

Figure 11. Cooling system filling.
14. Drain the distilled water fill.
15. Repeat this rinse process an additional cycle (repeat steps 13 and 14).
16. Once again, drain the distilled water fill.
17. If the coolant expansion tank is still discolored
after the cleaning process it must be replaced
(Figure 12).

Figure 12. Discolored coolant expansion tank.

Page 7 of 11
© 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.

18. Fill the cooling system with coolant at the proper
mix ratio of coolant and distilled water according to
the procedure in ElsaPro (Figure 13). Perform
bleeding procedure.

Figure 13. Cooling system filling.
Note:
Do not reuse any of the cleaning and coolant solutions used during this process.
19. Replace the heater core only in cases where normal cabin heating performance is not restored after
performing this cleaning and flush procedure and the root cause is confirmed to be an obstructed heater
core.

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:

8023

Damage Code:

0016

Labor Operations:

Drain and fill cooling system (4 x drain, fill and
bleed operations)

1938 17XX

See SRT with
associated
operations

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© 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.

Empty and clear out heater core, fill and clean
using cooling system cleaning set (4 cylinder
engines)

8023 9999

160 TU

Empty and clear out heater core, fill and clean
using cooling system cleaning set (‘V’ and ‘W’
engines)

8023 9999

250 TU

For vehicles that have a second heat
exchanger: Empty and clear out heater core,
fill and clean

8823 9999

100 TU

GFF – Checking and clearing fault codes
included in existing labor operations

0150 0000

Time stated on
the diagnostic
protocol (Max 40
TU)

Road test prior to the service procedure

0121 0002

10 TU

Road test after the service procedure

0121 0004

10 TU

Or

Diagnostic Time:

Claim Comment:

As per TSB #2062583/1

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.

Required Parts and Tools
Always check with your Parts Department and/or ETKA for the latest information and parts bulletins.
Part Number

Part Description

Quantity

See ETKA

Fasteners, Bolts, Nuts, and Screws as needed per the
Repair Manual

See ETKA/ELSA

Page 9 of 11
© 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.

G052525A3

01

Cooling system cleaning set
See ETKA

Tool Number

Coolant

30 liters

Tool Description

T10007B

Analog Refractometer
VAS 6096

Cooling system charge kit

Page 10 of 11
© 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.

VAG 1274/X

Adapter

Additional Information
All parts and service references provided in this TSB (2062583) are subject to change and/or removal.
©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
these materials be modified or reposted to other sites without the prior expressed written permission of the
publisher.

Page 11 of 11
© 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.