Technical Service Bulletin
01 MIL on (P0491 and P0492 stored at same time)
01 14 89 2033001/6 August 19, 2014. Supersedes Technical Service Bulletin Group 01 number 13-48 dated
December 20, 2013 for reasons listed below.
Model(s)

Year

S4

2010 - 2011

A5

2010

S5 Cab

2010 - 2013

A6

2009 - 2012

A7

2012

Q5

2010 - 2012

Q7

2011 - 2012

VIN Range

Vehicle-Specific Equipment

All

3.2 FSI AVS and 3.0 TFSI engines

Condition
REVISION HISTORY
Revision

Date

Purpose

6

-

Revised header data (Added model)
Revised Warranty (Added labor operations)

5

12/20/2013

Revised Service (Updated ODIS testing instructions)
Revised Warranty (Added TUs)

4

10/10/2013

Revised header data (Added model)
Revised Service (Added ODIS instructions)

3

8/20/2013

Revised Warranty (Changed claim type)

2

5/29/2013

Revised header data (Added models)
Revised Service (Added information)
Revised Required Parts and Tools (Added part)

1

3/29/2013

© 2014 Audi of America, Inc.

Initial publication

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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
• MIL on.
• Both of the following DTCs are stored in the engine control module, J623 (address word 01):
• DTC P0491 (Secondary Air System Insufficient Flow, Bank 1)
• DTC P0492 (Secondary Air System Insufficient Flow, Bank 2)
• Mileage is greater than 15,000 miles.

Technical Background
Under certain driving conditions, the secondary air ports in the cylinder head can accumulate carbon over time,
causing a restriction.

Production Solution
Not applicable.

Service
Please note that before performing this repair for the first time, it is mandatory that the technician complete Audi
Academy Course #940134 and assessment #940134B. Otherwise, the warranty claim will be denied. The course
and assessment can be found on the Audi Academy CRC site. Specific video sections are reference in the
instructions below.
Perform ODIS Testing
1. Delete all DTCs. Bring the engine to operating temperature.
2. Go to Control Modules >> 01 Engine Control Module >> Control module OBD>> Basic Settings >> Checking
Secondary Air System.
3. Select MVB: MASS_SA_REL[0] and MASS_SA_REL[1].
4. Perform test (Press brake and gas pedal at the same time, start test on ODIS tester).
5. While Basic Setting test is running, check if the secondary air pump runs normally (no unusual noises). In
addition, check for a leak in the secondary air hose routing between the pump and combi valves.
6. Immediately after the test is complete, read MASS_SA_REL[0] and MASS_SA_REL[1]. If the values are
between 0.1 and 0.7, and there were no issues with the pump and hoses, the system needs to be cleaned.
Follow the instructions below.
Tip: Always use the latest version of this TSB.

© 2014 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
Prepare for Power Washing
1. Move the exhaust sliding bushings (that connect
the catalytic converter and muffler) back, then
lower the catalytic converter pipes (Figure 7).
For Q7, unbolt muffler from catalytic converter.
Cover mufflers with plastic bag to prevent water
from entering.
Cleaning water will drain out of the catalytic
converter pipes during the cleaning process.

Figure 7. Lowered catalytic converter pipes
2. Remove all spark plugs and cover the engine harness plugs for the coils (for water protection).
3. Drain the coolant so that it can be reused.
4. Bring front end of the car into service position (for Q5, A6, S4, and S5 Cabrio) to make room in the front of the
engine. The Q7 has enough room for access to the front of the cylinder heads.
5. For 3.0T only: remove the coolant supply lines
(intercooler of supercharger) in the front of the engine
(Figure 8).

Figure 8. Front coolant pipes to be removed for 3.0T

© 2014 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
6. Remove the following components:
• Coolant pipe (Figure 9,1)
• Coolant flange (Figure 9,2)
• Pulley and if needed bracket, of power
steering pump (Figure 9,3)
• Pulley of water pump (Figure 9,4)
• Coolant tube (Figure 9,5)
• Dipstick tube (Figure 9,6)

Figure 9. Engine component removal
Note:
When removing the dipstick tube, turn it 180 degrees, then reinstall it for water protection.
Note:
To loosen the coolant tube, remove 2 bolts (Figure 10, A and C),
open clip (Figure 10, B), and pry bushing apart as shown in training
video (Figure 10, D). There is no need to loosen the AC compressor.
Cover opening of right coolant pipe to prevent coolant circuit
contamination.

Figure 10. Loosening the coolant tube
7. Remove main port freeze plug by hitting the marked
area with a small punch until it turns (Figure 11).
Remove with pliers.

Figure 11. Marked area on main port of freeze plug.
© 2014 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
Prepare to Power Wash

Warning:
• Read pressure washer user manual and follow these safety instructions.
• Always insert special cleaning hose into adaptor and engine before turning pressure washer on.
• If switching special cleaning to a different port, turn pressure washer off and release residual pressure by
pulling the trigger before removing the special cleaning hose from the engine.
• Wear safety glasses and gloves.

1. Become familiar with the special tool set VAS6825 (Figure 12):
• Special hose with scale for cleaning single
ports (Figure 12,1)
• Special hose for cleaning the main ports
(Figure 12,2)
• Hose adaptor for the special hose with
scale (Figure 12,3)
6 • Engine adaptor for bank one (Figure 12,
4a)
• Engine adaptor for bank two (Figure 12,
4b)

Figure 11. Special tool set VAS6825
2. To catch water, put a pan under the front of the engine and under the disconnected catalytic converter pipes.
3. Install engine adaptors on the appropriate banks (Figure 13,
Figure 14).

Figure 13. Engine adaptor on bank one.

© 2014 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

Figure 14. Engine adaptor on bank two.
4. To ensure proper pressure washer function, use a ¾-inch water supply hose (no longer than 60 feet) to
supply pressure washer.
The Audi-supplied pressure washer comes with a 22mm male-to-male adapter (to connect special tool to
trigger gun), a pressure gauge (to connect between pressure washer and high pressure hose), and a 220V
power adapter.
Make sure that pressure is at least 1800 psi when using the special single port cleaning hose (the hose with
the scale). Use the table below to compensate for low water pressure:

psi While Cleaning Single Ports

Cleaning Time in Minutes

Less than 1900

Pressure too low – check water supply

1900

4

2000 or higher

3

Power Wash the Ports
Cleaning Main Secondary Port:
1. Insert special main port cleaning hose (the hose without the scale) two inches into the engine adaptor.
2. Turn the pressure washer on.
3. Holding the cleaning hose tightly, pull the pressure washer trigger.
4. Gradually move the cleaning hose into the port, going back and forth until the combi valve is reached. All water
comes out at the adaptor #4.
5. Continue going back and forth through the whole port until only clean water drains out of the cylinder head.
6. Do the same with the other cylinder head.

© 2014 Audi of America, Inc.

Page 6 of 11

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
Cleaning Single Ports:
1. Because every port has a different distance to the cylinder head, use the table below to position the hose
adaptor for the special single port cleaning hose (the hose with the scale) correctly into the hose. The back
side of the hose adaptor must align with the number on the scale of the cylinder to be cleaned (Figure 14). The
longitudinal slot on the hose adaptor must align with the black line on the scale for correct rotational
positioning (Figure 15).

Dimensions Port

1

2

3

Bank One

10.5

19.5

28.5

Bank Two

13.7

22.7

31.8

Figure 15: Arrow indicating how the back side of the adaptor must align with the scale. Red dotted
line indicating how the longitudinal slot must align with the black line on the scale.

2. After adjusting the position of the hose
adaptor, insert the special single port
cleaning hose into the hose adaptor,
and bring it back into locking position
(Figure 16).

Figure 16. Locking position / transvers longitudinal movement and of
the hose adaptor
3. While cleaning, make sure that the pressure washer is supplying pressure greater than 1800 psi.
4. Based on the washer’s pressure, clean the port based on the table below. While cleaning, continuously move
the hose adaptor within the longitudinal and transvers slots (Figure 16).

© 2014 Audi of America, Inc.

Page 7 of 11

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
psi While Cleaning Single Ports

Cleaning Time in Minutes

Less than 1900

Pressure too low – check water supply

1900

4

2000 or more

3

Tip: After ten seconds of cleaning, all of the water should be draining out of the exhaust. If water is draining
out of the engine adaptor, check the position of the hose adaptor on the hose.
5.

Do the same for all remaining cylinders.