M0067812-00

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Special Instruction
Aftertreatment Outlet NOx Sensor Internal Water Shield Installation {108U}
Media Number -M0067812-00
Publication Date -22/01/2016
Date Updated -22/01/2016
i06577165
Aftertreatment Outlet NOx Sensor Internal Water Shield Installation {108U}
SMCS - 108U
On Highway Truck
CT660S (S/N: TJD1-UP; TEJ1-UP; TEM1-UP; TEP1-UP; TRR1-UP; TEY1-UP; TEZ1-UP)
CT680 (S/N: TWT1-UP; TKW1-UP; TRX1-UP; TRZ1-UP)
CT681 (S/N: TWJ1-UP)
Truck
CT660S (S/N: TRY1-UP)
Introduction
Do not perform any procedure in this Special Instruction until you have read the information and you understand the
information.
Description
Water intrusion can cause the malfunction or failure of the aftertreatment outlet NOx sensor on vertical exhaust
configurations. See below for a list of feature codes for vertical exhaust configurations on Cat vehicles. The recommended
repair is to install a rain shield which prevents water from traveling down vertical exhausts from contacting the outlet NOx
sensor. Follow the diagnostic steps in this article to determine if your vehicle should be repaired by installing the
aftertreatment rain shield in the outlet of the Selective Catalytic Reduction (SCR) catalyst.
Vertical exhaust configuration feature codes:
z
07BJU
z
07BJX
z
07DXM
Symptoms
Diagnostic Trouble Codes And Dashboard Indicator Lights
Table 1
SPN
FMI
Code Description
Lamp
3226
4
Aftertreatment 1 Outlet NOx Sensor Circuit - Voltage Below Normal or Shorted to Low
Source
Amber
3226
10
Aftertreatment 1 Outlet NOx Sensor - Abnormal Rate of Change
Amber
5031
10
Aftertreatment 1 Outlet NOx Sensor Heater - Abnormal Rate of Change
Amber
Customer Observations or Concerns
Customers may experience a Malfunction Indicator Light (MIL) and possible reduced engine performance.
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Required Tools
Table 2
Tool Description
8 mm (5/16 in) Drill bit
End wrench
Center punch
Cleaning solvent
Electrical drill
Flathead screwdriver
Masking tape
Metal file
Needle nose pliers
Rubber gloves
Ruler of at least 6 inches
Safety Glasses
Sand paper 40-60 grit
Shop towels
Stir stick
Service Parts Information
Table 3
Qty
Part Number
Part Name
1
435-2880
Circuit Board As
2
435-4269
Film
1
435-3074
Gasket
1
536-2108
High Temperature Sealant
Diagnostic Steps
Table 4
Troubleshooting Test Step
Value
Results
Result: There are codes from Table
***#i06564440/i06564440.1*** that are active.
1. Verify the concern of the customer.
Repair: Follow the steps below in the "Repair" section to
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install a water shield. Diagnose the NOx Out sensor using the
steps in the appropriate diagnostic manual.
A. Use a PC with the engine diagnostic
software to read the fault codes.
Are the fault codes from Table
***#i06564440/i06564440.1*** active?
Fault
Codes
Result: There are not any codes present from Table
***#i06564440/i06564440.1*** .
Repair: Exit this procedure and return to the appropriate Fault
Code Action Plan (FCAP) to continue to troubleshooting the
fault codes.
Repair Steps
A diesel particulate filter will become extremely hot during engine
operation. A hot diesel particulate filter can cause a burn hazard which
could result in personal injury. Allow adequate cooling time before
working on or near the diesel particulate filter.
Removal Procedure
1. Remove the aftertreatment SCR assembly from the chassis. Refer to the Disassembly and Assembly manual for the
appropriate procedure.
View Image
Illustration 1
(1) Outlet NOx sensor
g06031583
2. Remove outlet NOx sensor (1) from the SCR.
Inspection, Drilling, and Cleaning Procedure
Note: Do not use a metallic object to clean the SCR catalyst. Metal will scratch the surface of the SCR catalyst which may
cause excessive diesel fluid build-up.
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Note: Do not use any chemical solvents or cleaners to clean the internal metal surface. Possible damage to the SCR
catalyst may occur.
Note: Every SCR catalyst unit has a drain hole which allows water that has accumulated in the unit to drain out of
the system. A plugged drain hole can cause an outlet NOx sensor to malfunction. The drain hole must be clear of
debris, dirt, or any other material.
View Image
Illustration 2
(1) SCR drain hole
g06031992
1. Clean the dirt and debris from SCR drain hole (1).
View Image
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Illustration 3
(1) SCR drain hole
(2) SCR catalyst outlet
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g06032008
a. The drain hole (1) is oriented in the lowest section of the SCR catalyst outlet (2) pointing towards the ground.
View Image
Illustration 4
(2) SCR catalyst outlet
(3) Template
g06032018
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2. Cut template (3) for either a Marmon or Torca joint.
Note: The template has information for selection of the proper joint.
3. Attach the appropriate template to the SCR catalyst outlet pipe as shown in the illustration above.
View Image
Illustration 5
(3) Template
g06032054
4. Use a center punch to mark the designated locations on template (3).
5. Drill holes using the specified bit size from the template.
6. Remove the template from SCR catalyst outlet pipe.
7. Remove any burrs from the holes that were drilled using a metal file.
8. Clean the metal shavings out of the SCR catalyst.
Note: Any shavings left in the SCR catalyst could clog the drain hole.
View Image
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Illustration 6
(4) Sensing wheel cup screen
(5) Masking tape
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g06032071
9. Mask off sensing wheel cup screen area (4) using masking tape (5) as seen in the illustration above.
10. Roughen up the smooth surfaces of the SCR catalyst pipe on either side and directly above the sensing wheel cup
area using 40 or 60 grit sand paper.
11. Roughen up the top of the outlet NOx sensor internal water shield surface using 40 to 60 grit sand paper.
Use all cleaning solutions with care and in a well ventilated area. Always
wear eye protection when using cleaning solutions. Failure to follow the
precautions provided by the manufacturer on using, storing and
disposing of any cleaning solution can result in bodily injury.
12. Use a cleaning solvent to clean the surfaces thoroughly from oil, grease, dirt, corrosion, or other contaminants.
View Image
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Illustration 7
(5) Masking tape
(6) Outlet NOx sensor internal water shield
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g06032230
13. Attach masking tape (5) to the outlet NOx sensor internal water shield (6). Leave 1 inch of exposed metal as shown
in Illustration 7.
Installation
View Image
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Illustration 8
(6) Outlet NOx sensor internal water shield
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g06032234
1. Orient outlet NOx sensor internal water shield (6) towards the SCR catalyst outlet. Refer to Illustration 8 with the
directional air flow arrow.
2. Install two cap screws and washers from the outside and hand tighten. Tighten the caps screws to 7.3 N·m (65 lb in).
View Image
Illustration 9
(2) SCR catalyst outlet pipe
(5) Masking tape
(6) Outlet NOx sensor internal water shield
g06032243
3. Attach masking tape (5) to SCR catalyst outlet pipe (2).
a. Apply the masking tape 1 in high by 4 in wide about 1 in above outlet NOx sensor internal water shield (6).
Note: The masking tape will help remove excessive high temperature sealant.
Use all cleaning solutions with care and in a well ventilated area. Always
wear eye protection when using cleaning solutions. Failure to follow the
precautions provided by the manufacturer on using, storing and
disposing of any cleaning solution can result in bodily injury.
View Image
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Illustration 10
(7) High temperature sealant
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g06032248
4. Mix high temperature sealant (7) through for 1 minute.
Note: Do not allow the high temperature sealant to fall into the SCR catalyst during application.
View Image
Illustration 11
g06032255
(2) SCR catalyst outlet pipe
(5) Masking tape
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(6) Outlet NOx sensor internal water shield
(7) High temperature sealant
Note: All surfaces must be free of oil, grease, dirt, corrosion, and other contaminants before using the high
temperature sealant.
5. With rubber gloves, use a finger or application tool to apply high temperature sealant (7) evenly to seal the gap
between SCR catalyst outlet pipe (2) and outlet NOx sensor internal water shield (6).
Note: make sure that the sealant completely fills the gap or air pockets can form and bonding will fail.
View Image
Illustration 12
(7) High temperature sealant
g06032259
6. Remove excess high temperature sealant using a rag or gloved hand.
7. Remove the masking tape from the SCR catalyst outlet and internal water shield.
Note: Masking tape must be removed before the high temperature sealant hardens. At room temperature, the sealant
will harden in around 4 hours.
8. Install the outlet NOx sensor.
9. Install the SCR catalyst assembly.
10. For the high temperature sealant to cure, run a stationary regeneration after installing the SCR catalyst assembly.
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