Technical Service Bulletin
01 MIL on (P0491 and P0492 stored at same time)
01 13 83 2033001/1 March 29, 2013.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

A6

2009 - 2011

All

Engine code CCAA

A6

2010 - 2011

All

Engine code CALA

Q7

2011 - 2012

All

Engine code CJWE

Q7

2011 - 2012

All

Engine code CJWC

Q7

2011 - 2012

All

Engine code CJWB

A4

2009 - 2011

All

Engine code CALB

A4

2010 - 2011

All

Engine code CCBA

Q5

2009 - 2012

All

Not applicable

Condition
• MIL on.
• DTC P0491 and P0492 (Secondary Air System Insufficient Flow, Bank 1/2) are stored at the same time.
• 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.

© 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
Service
Tip: This TSB will be updated soon. Please use the latest revision.
For Q5, S4 and A6 3.0T, follow the steps below. For A6 3.2AVS and Q7 3.0T, call Technical
Assistance Center (TAC). 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 VAS Testing
1. Delete all DTCs and bring the engine to operating temperature.
2. Go into Basic Setting in the VAS tester (VSD) and select Secondary Air System Check.
3. Start the test on the VAS tester.
4. Depress the brake pedal first, followed by the gas pedal.
5. Record MVBs:
PRS_SA_DIF (record max value)
MASS_SA_REL (recode value at the end of test)
• If PRS_SA_DIF max pressure is below 170mbar, follow GFF for these DTCs.
• If max value of PRS_SA_DIF is greater than 170mbar / hPa and MASS_SA_REL below 0.6, the
secondary air ports have to be cleaned. Follow the steps below.

Tip: To restart the test, back out of VSD to the main screen and cycle the key.

© 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
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 1).
Cleaning water will
drain out of the
catalytic converter
pipes during the
cleaning process.

Figure 1. Lowered catalytic converter pipes
2. Remove all spark plugs.
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 2).

Figure 2. Front coolant pipes to be removed for 3.0T
6. Remove the following components:

© 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
• Coolant pipe
(Figure 3,1)
• Coolant flange
(Figure 3,2)
• Pulley and if
needed bracket,
of power steering
pump (Figure
3,3)
• Pulley of water
pump (Figure
3,4)
• Coolant tube
(Figure 3,5)
• Dipstick tube
(Figure 3,6)

Figure 3. 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 4, A and
C), open clip (Figure 4, B), and pry bushing apart as shown
in training video (Figure 4, D). There is no need to loosen
the AC compressor.
Cover opening of right coolant pipe to prevent coolant circuit
contamination.

Figure 4. Loosening the
coolant tube
7. Remove main port
freeze plug by hitting
the marked area
with a small punch
until it turns (Figure
5). Remove with
pliers.
Figure 5. Marked area on main port of freeze plug.
© 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
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 6):
• Special hose
with scale for
cleaning single
ports (Figure
6,1)
• Special hose for
cleaning the
main ports
(Figure 6,2)
• Hose adaptor for
the special hose
with scale
(Figure 6,3)
• Engine adaptor
for bank one
(Figure 6, 4a)
• Engine adaptor
for bank two
(Figure 6, 4b)

Figure 6. Special tool set VAS6825

2. To catch water, put a pan under the front of the engine and under the disconnected catalytic converter
pipes.

© 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
3. Install engine
adaptors on the
appropriate banks
(Figure 7, Figure 8).

Figure 7. Engine adaptor on bank one.

Figure 8. 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

© 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
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.
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 9). The longitudinal slot on the hose adaptor
must align with the black line on the scale for correct rotational positioning (Figure 9).

Dimensions Port

1

2

3

Bank One

10.5

19.5

28.5

Bank Two

13.7

22.7

31.8

Figure 9: Arrow indicating how the back side of the adaptor must align with the scale. Red dotted