Technical Service Bulletin
20 MIL on (DTC P045600 - EVAP System Leak Detected NVLD (very small leak))
20 13 28 2035073/2 November 14, 2013. Supersedes Technical Service Bulletin Group 20 number 13-27 dated
October 16, 2013 for reasons listed below.
Model(s)

Year

A4/S4

2013 - 2014

A5/S5

2013 - 2014

A5/S5 Cab

2013 - 2014

A6

2012-2014

A7

2012-2014

Q5

2013 - 2014

VIN Range

Vehicle-Specific Equipment

All

Not Applicable

Condition
REVISION HISTORY
Revision

Date

Purpose

2

-

Revised header data (Added Q5)

1

10/16/2013

Initial publication

• MIL on.
• DTC P045600 (EVAP System Leak Detected NVLD (very small leak)) is stored in the engine control module
(ECM), J623 (address word 01).
• Drivability is not affected.

Technical Background
After the engine is switched off, the fuel system creates a natural vacuum as the fuel in the fuel tank cools off. If
the natural vacuum leak detection (NVLD) system cannot detect this natural vacuum during the system self-test,
the DTC will be stored in the ECM.
System self-test background:
• The NVLD system checks the natural vacuum that is created in the fuel tank as the fuel cools after the engine
has been switched off.
• The fuel tank pressure sensor, G400, senses the vacuum in the bleed line near the EVAP canister. The fuel
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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
tank leak detection control module, J909, monitors the temperature inside the fuel tank.
• The fuel system is considered to be closed (leak-free) if the measured vacuum is 2.5 mbar (0.04 PSI).
• If no vacuum is detected, there is a vacuum leak in the EVAP system, and the DTC will be stored.
System self-test requirements:
• For the self-test to initiate, the following requirements must be met:
• Ignition is off.
• Ambient air temperature is greater than -10°C (14°F).
• Fuel temperature drops for more than one hour by more than 6°C
(11°F). This varies by model; see Elsa >>Engine >> Generic Scan
Tool >> ST Generic Scan Tool >> Diagnosis and Testing >> DTC
Tables.
• Example of a 6°C (11°F) drop: From 10°C (50ºF) to 4°C (39ºF)
within one hour (Figure 1).

Figure 1. Example of a 6°C (11°F)
drop: From 10°C (50ºF) to 4°C (39ºF)
within one hour.
• Altitude is less than 2700 m (8858 ft.).
• Ambient pressure is greater than 730.04 hPa (10.6 PSI).
• Time since ignition has been off is more than 1.5 hours but less than 10 hours.
• Difference between ambient pressure at stop and ambient pressure at start is less than 6.47 hPa (0.09 PSI).

© 2013 Audi of America, Inc.

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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
Production Solution
New pressure sensors in production:
• For vehicles with a fuel tank pressure sensor, G400, and a fuel tank leak detection control module, J909, that
are separate (two components): part numbers 8K0906253 and 8K0906253B are superseded to 8K0906253D.
• For vehicles with a fuel tank pressure sensor, G400, and a fuel tank leak detection control module, J909, which
are integrated (one component): part numbers 8K0906253A and 8K0906253C are superseded to
8K0906253E.
Note: Always use a VIN to search parts in ETKA.

Service
Use the images below to determine the type of EVAP system:
• Separate fuel tank pressure sensor, G400, and fuel tank leak
detection control module, J909 (Figure 2).

Figure 2. Separate sensor and control module.
• Integrated fuel tank pressure sensor, G400, and fuel tank
leak detection control module, J909 (Figure 3).

Figure 3. Integrated sensor and control
module.

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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
Note:
Due to the functionality of the new tank leak diagnostic system (NVLD), it is not possible to check the system
using a basic setting or an output diagnostic test mode like the previously-used LDP system.

Diagnosis
1. Visually inspect the EVAP system for any loose connections or damaged parts:
• If found, repair the loose connections and replace the damaged parts.
2. Check N80 valve for proper operation (Engine >> Generic Scan Tool >> ST Generic Scan Tool >> Diagnosis
and Testing >> Diagnostic Procedures >>EVAP Purge Regulator Valve, Checking):
• Replace the valve if faulty.
3. Inspect fuel cap and address any issues before advancing to the next step:
• If the fuel cap is loose / not properly installed, reinstall the cap.
• If the fuel cap seal is damaged, replace the seal.
• If foreign objects are obstructing the sealing surface, remove the obstruction.
4. Test the fuel cap using the Evaporative Emissions Tester KLI9210:
• If necessary, replace the fuel cap seal or fuel cap.
5. Pressurize the EVAP system using the KLI9210
Smoke/Pressure test:
• Disconnect the air filter hose from the pressure
sensor. Seal the pressure sensor opening with a
clean plug from the Engine Bung Set VAS 6122, or
similar (Figure 4 and Figure 5). The plug must fit
securely and not allow any air to leak.
• Pressurize the EVAP system to 12 inch/water
(30mbar), and check pressure loss over time.
Figure 4. Example of plug inserted inside the
pressure sensor filter pipe.

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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

Figure 5. Example of plug inserted over the pressure
sensor filter pipe
6. If remaining pressure after 3 minutes is 9 inch/water (22.4 mbar) or higher, the system has no leaks:
• Replace the pressure sensor (G400 or G400/J909) with the latest part number (see parts catalog).
If remaining pressure after 3 min is lower than 9 inch/water (22.4 mbar), the system has a leak.
• Locate the leak with the smoke generator function of the Evaporative Emissions Tester KLI9210 and
repair as necessary.

© 2013 Audi of America, Inc.

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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
Warranty
Claim Type:

Use applicable claim type. If vehicle is outside any warranty, this Technical Service Bulletin
is informational only.

Service Number:

2041

Damage Code:

0040

Labor Operations: EVAP system pressure test

2041 0199

70 TU Max

NVLD J909 pressure switch replacement

2041 0199

10 TU

A4/S4, A5/S5, A5/S5 Cabrio, Q5:

2025 1910

50 TU

2025 1900

40 TU

0150 0000

Time stated
on diagnostic
protocol (Max
40 TU)

Activated charcoal filter remove & reinstall
A6/A7:
Activated charcoal filter remove & reinstall
Diagnostic Time:

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

Technical diagnosis at dealer’s discretion
(Refer to Section 2.2.1.2 and Audi Warranty Online for DADP allowance details)
Claim Comment:

As per TSB #2035073/2

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.

Additional Information
All parts and service references provided in this TSB (2035073) are subject to change and/or removal. Always
check with your Parts Department and service manuals for the latest information.

© 2013 Audi of America, Inc.

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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.