A8722242064077_1

Technical Service Bulletin
87 Air conditioning refrigerant circuit diagnostic method using calibration gas
87 22 24 2064077/1 April 15, 2022.
Page 1 of 13
© 2022 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
Model(s)
Year
A4 allroad, A4,
S4, A5, A5
Cabriolet, A5
Sportback, S5,
S5 Cabriolet, S5
Sportback, A6,
S6 A7, S7, Q3,
A5, SQ5, Q7,
TT, TTS, and TT
Roadster
2018 – 2023
A3 Cabriolet
2018 - 2019
A3, and S3
2018 – 2020
2022 – 2023
RS 3
2018 – 2020
2023
RS 5
VIN Range
Vehicle-Specific Equipment
All
Not Applicable
2018 – 2019
2021 - 2023
RS 7
2018
2021 - 2023
A8
2018 – 2021
2023
S8
2020 – 2021
2018
2023
2018
R8, and R8
Spyder
2020 – 2023
TT RS
2018 – 2022
RS 5 Sportback
e-tron quattro
2019
2021 – 2023
2019
2021 – 2023
Q8
2019 – 2023
A6 allroad, etron Sportback
quattro, SQ7,
SQ8, and RS Q8
2020 – 2023
Page 2 of 13
© 2022 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
A8 e quattro
Q5 e quattro
2020 – 2021
2020 – 2021
2023
RS 6 Avant, Q5
Sportback, and
SQ5 Sportback
2021 – 2023
A7 e quattro
2021 – 2022
e-tron GT, and
RS e-tron GT
2022 – 2023
Condition
The cabin air conditioning cooling capacity is insufficient or without function on an R134a or R1234yf
refrigerant system equipped vehicle.
Technical Background
When a refrigerant circuit leak is determined as the root cause of a cabin cooling insufficiency it has
traditionally been diagnosed using either the addition of a contrast dye into the circuit and inspection using
ultraviolet light, the use of an electronic halogen leak detector, or filling the circuit with pressurized nitrogen
and searching for the leak by applying a liquid soap and water solution and inspecting the circuit for the
presence of bubble formation. These methods can be unreliable, particularly when diagnosing a possible
refrigerant leak in the evaporator core.
When diagnosing a possible leak from an evaporator core, false-positive readings from a halogen leak
detector are common and visual access to the evaporator core in an attempt to inspect for the presence of
contrast dye or bubble formation is problematic at the very least.
An additional diagnostic method is now available to analyze a refrigerant leak in the circuit of an R134a or
R1234yf refrigerant system using calibration gas (95% nitrogen / 5% hydrogen) and an electronic hydrogen
detector (VAS523003A). Leak detection using calibration gas has been found to be more effective when
diagnosing a leak source in the areas of the refrigerant circuit that are extremely difficult to access (e.g. the
evaporator core concealed inside the evaporator housing).
Page 3 of 13
© 2022 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
Production Solution
Beginning with the R744 refrigerant system in the new Q4 e-tron the leak detection method for this
refrigerant system requires a process that prohibits the use of additives of any kind when diagnosing a leak,
creating the need for a leak detection method using calibration gas. This requires a new tool set. The AT-448
Tool Set Audi R744 CO2 A/C Service Introduction (See Service Information circular – Special Tools and
Equipment number ATE-21-21) is now released to all dealers. The tools in this set can be adapted to
diagnose R134a and R1234yf refrigerant circuit leaks as well.
Service
Note:
The procedure in this TSB describes a method for leak detection for R134A and R1234yf refrigerant
platforms only. While the diagnostic method for the R744 system in the Q4 e-tron is similar there are
important differences in the procedure and, as such, should be carried out using the procedure in ElsaPro.
Warning:
Extreme caution must be exercised when handling and using calibration gas. The hydrogen component of
the gas mixture is flammable. Failure to employ proper handling and use protocol invites the risk of serious
personal injury or death.
1.
Should the vehicle arrive with insufficient cabin cooling from the air conditioning system recover the
refrigerant remaining in the circuit and compare this amount to the specified volume. A significantly
lesser amount recovered (>50% of total volume lost) indicates an active refrigerant circuit leak.
Page 4 of 13
© 2022 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
2.
Obtain a tank of calibration gas (95% nitrogen
/ 5% hydrogen) (Figure 1). This will need to be
sourced locally (e.g. Airgas®).
Figure 1. Calibration gas (95% Nitrogen / 5%
Hydrogen).
Page 5 of 13
© 2022 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
3.
The pressure regulator included in the
NITROKITG will not be used as it is only
suitable for connection to a gas tank
containing non-flammable gasses such as
nitrogen (right-hand thread). The AT-448 Tool
Set includes the VAS 584005 pressure
regulator suitable for connection to a gas tank
containing any flammable component as is the
case with the hydrogen component in
calibration gas (left-hand thread). Connect the
VAS 584005 pressure regulator to the tank
(Figure 2). Make sure the tank valve remains
closed.
Figure 2. VAS 584005 pressure regulator attached to
the calibration gas tank.
4.
Set the HVAC settings to full defrost. Close all of the instrument panel vents and make sure that the
fresh air intake is also closed (recirculation mode). Close off the cabin completely (windows, sunroof,
doors, rear lid, etc.). Then turn off the vehicle completely (key off, no blower activation).
5.
When servicing a high voltage vehicle de-energize the vehicle.
6.
The NITROKITG includes a service hose and high side service port snap coupler for both an R134a and
R1234yf refrigerant system. This will allow the single connection to the refrigerant circuit of both an
R134a as well as an R1234yf equipped vehicle. Use the snap coupler appropriate for the refrigerant
platform being serviced from the NITROKITG to complete the connection.
Page 6 of 13
© 2022 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
7.
Evacuate the vehicle refrigerant circuit for 15
minutes. After the refrigerant circuit is free of
any refrigerant connect the service manifold
from the NITROKITG Automotive A/C Nitrogen
Leak Test Kit to the high side service
port. Use the appropriate snap coupler for the
platform of the circuit being serviced. (Figure
3).
Figure 3. NITROKITG manifold connected to the high
side service port.
8.
Only one of the ports needs to be connected
for this diagnosis. The connection to the high
side port is shown in Figure 4.
Figure 4. NITROKITG high side snap coupler
connected to the high side service port.
Page 7 of 13
© 2022 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
9.
Connect the VAS 584005 Pressure Reducer to
the NITROKITG manifold. Fill the circuit with
calibration gas to an absolute pressure of no
greater than 14 bar (Figure 5).
Figure 5. Calibration gas pressure in the circuit.
Note:
The air conditioning system must not be activated while the circuit is charged with calibration gas. Running
the air conditioning system while it is charged with calibration gas will damage the compressor.
If necessary apply a warning sign to the vehicle stating “Do Not Run” or a similar warning to prevent
accidental operation while the circuit is filled with calibration gas for the purposes of diagnosis.
10. After the circuit is charged allow the circuit pressure to equalize for 20 minutes. Leak detection can
then begin.
Page 8 of 13
© 2022 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
11. Close off the defroster outlets with masking
tape leaving a small opening for the VAS
523003A gas leak detector probe (Figure 6).
Figure 6. VAS 523003A gas leak detector in place in
the defroster outlet.
Page 9 of 13
© 2022 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
12. The gas leak detector VAS 523003A reacts to
the hydrogen component in the calibration
gas. Since hydrogen is lighter than air, it will
rise to the position of the detector probe. The
hydrogen content in the calibration gas,
however, evaporates after a short period of
time (Figure 7).
Perform the leak diagnosis immediately after
charging the refrigerant circuit with calibration
gas and the 20-minute equalization period.
Depending on the conditions, it may be
necessary to recharge the refrigerant circuit
with calibration gas in an attempt to clearly
identify a circuit leak at the evaporator core.
Figure 7. VAS 523003A in place in the defroster outlet
and hydrogen presence is detected.
13. If no leak is detected through the defroster outlet using this method the evaporator core is not the
source of the refrigerant leak and the evaporator core is not to be replaced. Continue diagnosis using
the VAS 523003A along all remaining components of the refrigerant circuit to determine the source of
the leak.
14. When any and all leak sources have been identified close the valve on the top of the calibration gas
tank. Any calibration gas that remains in the refrigerant circuit can be slowly ventilated until the circuit
pressure has equalized with atmospheric pressure. Proceed with the necessary repairs, evacuate the
refrigerant circuit, and recharge the system as necessary.
15. When re-energizing a high voltage vehicle observe the following:
Page 10 of 13
© 2022 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
Warranty
This TSB is informational only and not applicable to any Audi Warranty.
Required Parts and Tools
Tool Number
Tool Description
VAS581009
R744 CO2 A/C Service Unit
VAS584005
Pressure Reducer and Hose
Page 11 of 13
© 2022 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
NITROKITG
Automotive A/C Nitrogen Leak Test Kit
VAS523003A
Gas Leak Detector
Additional Information
All part and service references provided in this TSB (2064077) 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.
©2022 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
Page 12 of 13
© 2022 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
otherwise, nor may these materials be modified or reposted to other sites, without the prior expressed
written permission of the publisher.
Page 13 of 13
© 2022 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.