not authorize the repair of any pre-existing
conditions. Please check whether or not this repair
could be covered by the warranty extension.

Proceed to Section D

Section D – A3 - Install 2.0L Gen 3 Phase 2A Kit
(NOx Sensor 2 w/ Exhaust Pipe)
NOTE
RISK of Non-payment!
Determining whether or not to install 2.0L Generation 3 Phase II A and/or B is dependent on the specific history
and current mileage of the vehicle. You MUST refer to the IN-FORM tool to identify if one (Kit 2A only) or both
(Kit 2A+2B) Kits are needed! Installing Kit B when only Kit A is needed will result in claim cancellation. Dealers
WILL NOT BE COMPENSATED for this error.
Removing air filter housing:


Unscrew bolts .



Release catch and remove cover .



Push cover towards front out of retainers
.



Remove cover .

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 10 of 75



Lay coolant hose to one side.



Release fasteners and remove upper
part of air duct .



Release and disconnect connector . Pull off
vacuum hose and unclip from intake hose
.



Loosen spring-type clip using spring-type
clip pliers -VAS 6362-.



Pull intake hose off air mass meter.



Pull hose for warm air intake off air filter housing.



Pull air filter housing upwards out of fasteners
and remove.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 11 of 75

Removing battery:


Turn the steering wheel to the straight ahead
position and remove the ignition key so that the
steering wheel lock engages.



Open cover in heat insulation sleeve.



Open cover on battery negative terminal.



Loosen nut several turns, and disconnect
battery clamp of earth cable from negative
battery terminal.



Open cover for positive battery terminal.



Loosen nut several turns, and disconnect
battery clamp of positive cable from positive
battery terminal.



Pull heat insulation sleeve upwards slightly.



Unscrew bolt on securing bracket .



Remove securing bracket .



Pull battery in direction of travel out of
battery tray and lift out of engine compartment.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 12 of 75

Removing battery tray:


Lay aside wiring harness on battery tray.



Separate electrical connector .



Release catches , remove control unit for
NOx sender 1 from bracket, and place it on
the engine.



Unscrew bolts .



Remove battery tray .

Routing adapter wiring harness:
NOTE
The lower end of the new wiring harness is enclosed in
a plastic bag to protect it from soiling. Do not remove
this protection until immediately before fitting.


Check that all connectors are clean and blow out
with compressed air as needed.



In the engine compartment, disconnect original
connector on control unit for NOx sender
and connect to adapter wiring harness.



Connect connector of adapter wiring harness
to control unit for NOx sender.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 13 of 75



Route adapter wiring harness from left
suspension turret to underbody. Clip it in at
indicated places on longitudinal member and
secure using cable ties .

Removing noise insulation:


Unscrew bolts .



Pull noise insulation towards the rear and out of
front bumper cover in .

CAUTION
Do not use a grinder or similar swarf-producing tool to
cut exhaust pipe.


Cut exhaust pipe using chain pipe cutter
-VAS 6254- along dashed line.
o

Dimension = 100mm.



Loosen clamp and push to rear. Remove
exhaust pipe .



Install new Exhaust Pipe with NOx Sensor bung.



Install new clamps.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 14 of 75



Slide new clamps 1K0.253.141.S onto exhaust
pipe.



Position exhaust pipe so that attached arrow
marking points in direction of travel and
perpendicularly downwards to ground.



Position clamps longitudinally on
exhaust pipe.



When doing this, observe indented markings
on exhaust pipe.

Installation position of clamp:




Install clamp at angle shown in illustration.
o

Angle = approx. 45°

o

Bolted connection facing towards right

o

Nuts may also face downwards.

Tighten clamp nuts to 30 Nm.

Installing NOx control unit:


Unscrew bolt .



Release retainers .



Pull front underbody cladding backwards to
direction of travel out of fasteners.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 15 of 75



Unscrew nuts and remove left middle
underbody cladding.

CAUTION
Cover exposed connectors and spray entire surface of
control unit with wax spray D 322 100 M2 (shop
supply) or equivalent. Under no circumstance may the
wax spray moisten the contacts of the control unit.


Set control unit for NOx sender 2 on welded bolts
to left on underbody.



Push on nuts to stop.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 16 of 75



Screw in NOx sender 2 and tighten to
52 Nm.



Secure wiring in retainer clips for exhaust flap
line.



Check that all connectors are clean and blow out
with compressed air as needed.



Connect adapter wiring harness on underbody to
control unit for NOx sender 2 .



Place cable ties at the points marked in color
.

NOTE
Do not drill into the underbody cover while it is installed
on the vehicle. Doing so may damage the vehicle and/or
its components, which is not covered under this action.


Prior to reinstalling the underbody panel, drill a 10
mm hole at the panel’s lowest point when
oriented as shown using a 10 mm drill bit .

If Kit 2B is required by the IN-FORM tool, proceed to
Section E.
If Kit 2A ONLY is required by the IN-FORM tool,
continue work procedure.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 17 of 75

Installing underbody cladding:


Install left middle underbody cladding and tighten
nuts to 2 Nm.



Insert mounting for front underbody cladding
in opening in middle underbody cladding
.



Push front underbody cladding forwards in
direction of travel until it engages audibly .

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 18 of 75

Installing noise insulation:


Push noise insulation forward into front bumper
cover at .



1 - Noise insulation panel



2 and 4 – Bolt





o

Qty. 3 left

o

Qty. 4 right

o

2.0 Nm

3 – Bolt
o

Micro-encapsulated; renew after each
removal

o

Qty. 3

o

6.0 Nm

5 – Bolt
o

Qty. 1 on lock carrier

o

1 Nm

Installing battery tray:


Set battery tray in place.



Screw in bolts and tighten to 9 Nm.



Secure wiring harness on battery tray again.



Install control unit for NOx sender in bracket on
battery tray and secure with cable ties, as
needed.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 19 of 75



Insert battery into battery tray so that battery
base strip lies against stop at bottom and sides
.
o



It should no longer be possible to move
battery towards rear or sides.

Fit securing bracket .
o

Make sure that lug on securing
bracket engages into recess in
battery base strip.



Tighten bolt for securing bracket to
15 Nm.



Ensure that battery is seated securely.



With ignition and electrical equipment switched
off, connect battery in the following sequence:



Fit battery clamp of positive cable to positive
battery terminal “+”.



Tighten nut to 6 Nm.

The repair information in this document is intended for use only by skilled technicians who have the proper tools, equipment and training to correctly and safely maintain your vehicle. These
procedures are not intended to be attempted by “do-it-yourselfers,” and you should not assume this document applies to your vehicle, or that your vehicle has the condition described. To
determine whether this information applies, contact an authorized Audi dealer. 2018 Audi of America, Inc. All Rights Reserved.
April 2018

23Y9 Page 20 of 75

Observe the following when connecting the battery:


If fitted, disconnect electrical connector on
control unit for battery monitoring -J367- .



Fit battery terminal clamp of earth cable to
negative battery terminal “-” by hand.



Tighten nut to 6 Nm.