Technical Service Bulletin

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

Condition
Model(s)

Year

Eng. Code

Jetta, Jetta
Wagon

2009

Golf

2010-2014

Jetta Sedan,
Jetta
SportWagen,
Golf Wagon

2010-2014

Beetle, Beetle
Convertible

2013-2014

Trans. Code

VIN Range
From

VIN Range To

All

All

All

All

All

All

All

All

All

All

All

All

2.0L TDI
(CBEA)
2.0L TDI
(CJAA)
2.0L TDI
(CJAA)
2.0L TDI
(CJAA)

Revision Table
Instance Number

Published Date

Version Number

Reason For Update

2034898/18

6/29/21

01-18-13

Update to parts table.

2034898/17

6/2/21

01-18-13

Update to text, warranty
and parts table, plus
additional testing
attachment.

2034898/16

10/1/20

01-18-13

Update to parts table
quantity.

2034898/15

9/24/2018

V011813

Update to parts table.

2034898/14

2/27/2018

V011803

Update to parts table.

2034898/13

11/29/2017

V011711

Modify service instruction
and to update GFF Time
expenditure in the
warranty table.

Page 1 of 14
© 2021 Volkswagen Group 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 Volkswagen Group 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

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

2034898/12

1/4/17

V011701

Update to parts table.

2034898/11

6/20/16

V011609

To update Golf
(exchange parts) time
units due to Saga/Elsa
updates 6/13/16.

Technical Background
High soot loads prior to regeneration can cause possible restrictions in the Exhaust Gas Recirculation
(EGR) filter.
Tools to assist technician when checking for charge air system leaks.

Production Solution
Information only.

Service
When diagnosing a vehicle with the fault P0401 perform the following:
 Remove the EGR filter from the Diesel Particulate Filter (DPF) and swipe the inside of the exhaust
pipe at the EGR filter connection point using a clean cloth or your finger. See figures 1 and 2 below.

Figure 1

Figure 2

If your finger or the cloth comes out with black soot:
 Replace the DPF & EGR filter together.
 Smoke test the charge air system for leaks (see procedure below).

Page 2 of 14
© 2021 Volkswagen Group 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 Volkswagen Group 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

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

Tip:
Proper intake airflow is essential for the longevity of the DPF. If a vehicle is found to have a damaged
DPF, it is advised to inspect the condition of the intake air filter and verify resting position of the warm air
valve (after the vehicle has cooled, see attachment).
If there is no soot on your finger or the cloth, continue with GFF diagnostics, this bulletin does not apply.
Note:
When replacing the DPF for the fault P0401 it is important to replace both the DPF and the EGR filter
together, as soot accumulation in the EGR filter is undesired. It is NOT necessary to replace any other
components for this fault (i.e. NOx Storage Catalyst, Sulfur Catalyst, Exhaust Flap, EGR Cooler). These
components should be reinstalled in the vehicle with the new DPF and EGR filter.
Refer to Tech Tip TT 26-13-02 (2035501) if you are unable to perform a regeneration after the
repair. The soot level adaptation may need to be reset.
Note:
Vehicles with a front single assembly exhaust (one piece DPF/NOx Cat.) will require additional
components. See parts table below. If the car has already had the DPF replaced once, and now
has the two piece DPF/Nox Cat., there is no need for the extra parts.
Note:
Proper intake airflow is essential for the longevity of the DPF. If a vehicle is found to have a damaged
DPF, it is advised to inspect the condition of the intake air filter and verify resting position of the warm air
valve (after the vehicle has cooled) as outlined in “Air Filter, Cleaning Housing and Replacing Filter
Element” section of the ELSA repair manual. Replace warm air valve (snow flap) if necessary.
Additionally, any leaks within the intake air system will cause additional stress to the DPF and a reduction
in engine performance. It is advised to reference TSB 21-15-06 - Engine Lacks Performance, DTCs
P2562, P2563, P2564, P2565, P2566, P0299, P20D8 or P00AF (2021771) and follow steps 4 - 5 to
ensure there are no leaks.

Page 3 of 14
© 2021 Volkswagen Group 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 Volkswagen Group 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

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

Charge Air System Testing
The charge air pressure system can be checked using the VAG
1687. Charge air system tester along with the VAG1687/10
adapter as follows:

Special tool VAG 1687 Charge air system tester, preliminary
set-up
 Back off pressure regulator knob -2- of VAG 1687 fully to
protect gauge when shop air supply is applied to the
assembly.
 Close valve -3- before gauge.
 Close valve -4- after gauge.
 Shop air supply line will later be attached to inlet of VAG 1687.
 Remove “female” fitting from tester (arrow) and install an
appropriate “male” air fitting that will connect to your shop air
supply line (See Note below).
Note:
Use only approved air fittings to adapt shop air supply line to VAG 1687 tester.
Special tool VAG 1687/10 pressure adapter, installing
On Golf, Jetta and New Beetle Models:
 Separate intake hose from the Mass Airflow Sensor assembly
(MAF).
 Insert VAG 1687/10 pressure adapter in intake hose -black
arrow- using existing clamp (as shown).
 Remove crankcase ventilation valve or tube from intake hose
at -white arrow-.
2.0L TDI shown

 Plug hose with appropriate metal plug and hose clamps
supplied with VAG 1687 special tool kit at -white arrow-.
Page 4 of 14

© 2021 Volkswagen Group 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 Volkswagen Group 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

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

Note:
To help find small leaks, BEFORE pressurizing the system, fill system with smoke using special tool
KLI9210 and adapter KLI9210/50 as outlined in this bulletin.
An Ultrasonic detector may also be used to detect extremely small leaks where smoke may not be visible.
Special tool KLI9210 (EVAP system leak detector)
 Install optional fitting KLI 9210/50 on hose of special tool
KLI9210.
 Connect KLI9210 to VAG 1687/1 adapter (KLI 9210 is shown
attached to VAG1687/1 at arrow on 1.8L Turbo).

1.8T shown

 Special tool KLI9210 (EVAP system leak detector)
 Install optional fitting KLI 9210/50 on hose of special tool
KLI9210.
 Connect KLI9210 to VAG 1687/1 adapter (KLI 9210 is shown
attached to VAG1687/1 at arrow on 1.8L Turbo).

Page 5 of 14
© 2021 Volkswagen Group 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 Volkswagen Group 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

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

 Special tool KLI9210 (EVAP system leak detector),
 preliminary set-up
 Setup KLI 9210 as described in user manual regarding selftest and output pressure.
 Connect smoke generator leads to vehicle battery.
 Turn valve to test (black arrow).
 Press smoke generator button to fill system with smoke (see
instructions printed on tester).
 Check for escaping smoke for two minutes.
Tip:
Smoke may escape from crankcase hose or oil fill hole. This
is normal.
With system filled with smoke:
 Remove smoke generator hose and connect VAG 1687
quickly to prevent smoke from leaking out.

 Connect VAG 1687 quickly to prevent smoke from leaking out.
Special tool VAG 1687 connecting to pressure adapter
1687/10
VAG 1687 is shown connected to VAG 1687/10 (black arrow)
Shop air supply connected to VAG 1687 at (white arrow).
 Perform pressure test.

1.8T Shown

Page 6 of 14
© 2021 Volkswagen Group 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 Volkswagen Group 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

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

Performing pressure Test:
 With outlet hose -1- of VAG 1687 connected to air pressure
adapter.
 Attach shop air supply line to previously installed male fitting.

 Open valve -3- between regulator valve and gauge.
 Adjust test pressure up to 0.5 bar (see Note below) by turning
the regulator valve -2-.
Note:
DO NOT pressurize system above 0.5bar.
Doing so may force oil into the intake system which can
damage the engine.
 Slowly open outlet valve -4- (after gauge) to test hose
connections.
Observe pressure gauge for a drop in pressure.
Tip:
Some pressure will be lost past the throttle plate.
If smoke generator was used to fill the system with smoke:
 Check for smoke escaping from intake connections.
Tip:
An Ultrasonic detector may also be used to detect extremely small leaks where smoke may not be visible.


Repair any leaks found.

 Remove tester.
 Remove plug from crankcase ventilation hose.
 Remove air pressure adapter.
 With VAS diagnostic tool connected:
 Erase DTC memory.
Page 7 of 14
© 2021 Volkswagen Group 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 Volkswagen Group 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

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

If smoke generator was not used to fill the system with smoke:
 Apply soapy water solution or equivalent to intake system connections.
Tip:
An Ultrasonic detector may also be used to detect extremely small leaks.


Inspect intake system connections for leaks.

 Repair any leaks found.
 Remove tester.
 Remove plug from crankcase ventilation hose.
 Remove air pressure adapter.
With VAS diagnostic tool connected:
 Erase DTC memory.
If no leaks are found, but complaint still exists, refer to Repair Group 21 in Elsa for detailed testing of
charge system components.

Page 8 of 14
© 2021 Volkswagen Group 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 Volkswagen Group 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

01-18-13 - MIL ON DTC P0401 Exhaust Gas Recirculation Flow
Insufficient

Transaction
No:

2034898/18

Release date:

6/29/2021

Warranty
To determine if this procedure is covered under Warranty, always refer to the Warranty Policies
and Procedures Manual 1)
Model(s)

Year(s)

Jetta, Jetta
Wagon

2009

Golf

2010-2014

Jetta Sedan,
Jetta
SportWagen,
Golf Wagon

2010-2014

Beetle, Beetle
Convertible

2013-2014

Eng. Code(s)

Trans.
Code(s)

VIN Range
From

VIN Range To

All

All

All

All

All

All

All

All

All

All

All

All

2.0L TDI
(CBEA)
2.0L TDI
(CJAA)
2.0L TDI
(CJAA)
2.0L TDI
(CJAA)
SAGA Coding

Claim Type:

Use applicable Claim Type 1)

Service Number:
2674