Mack Trucks
Greensboro, NC USA

Field Service Bulletin
Trucks
Date

Group

No.

Release

Page

11.2018

284

069

01

1(6)

Exhaust Particulate Sensor, Repair
2017 Models
CXU, CHU, GU

FSB 284-069, Exhaust Particulate Sensor, Repair
(2017 Vehicles)
(November 2018)
Some trucks built between 1/1/2017 and 11/14/2017 may experience a Particulate Matter
(PM) Sensor fault that can result in the MIL lamp illuminating. These faults may be P24DA,
“PM Sensor Exhaust Sample Error,” or P24D1, “PM Sensor Regen Incomplete.” These faults
may be caused by contamination of the PM sensor. In order to reduce the likelihood of
sensor contamination, new exhaust pipe parts are being made available that contain an
internal water management feature along with an integrated drain that will prevent
contamination of the sensor. If either of these two faults occur, follow the instructions outlined
in this bulletin to clean the exhaust pipes and install a new exhaust pipe with the new
contamination prevention measures.

PV729-FSB284-069_M

USA142168011

Mack Trucks
Field Service Bulletin

Date
11.2018

Group

No.

Release

284

069

01

Required Parts – All Years
Inspect and replace the v-band clamp as needed
A new gasket will be needed when disconnecting the SCR exit.
Note: No gasket needed for vertical SCR.
Part Description

Part Number

SCR Gasket

21095726

V-band Clamp

21021850

Particulate Matter Sensor

22946032

Note: Customer adaptations can change required parts. Check for adaptations before
ordering parts.

Parts List – 2017 Vehicles
Model

Cab
Type

Exhaust
Configuration

Pipe 1
Part
Number

Pipe 2
Part
Number

Flex Pipe
Part
Number

Clamp
Part
Number
(Qty will
vary)

CX/CH/
GU8

Day Cab

Single
Outlet
Right Side
Outboard

(Not
Bright)
23155759
(Bright)
23155760

N/A

23154829

20961913

GU7

Day Cab
without
front
body
attachment
plate

Single
Outlet
Right Side
Inboard

(Not
Bright)
23155764
(Bright)
23155765

N/A

23154829

20961913

GU7

Day Cab
with front
body
attachment
plate

Single
Outlet
Right Side
Outboard

(Not
Bright)
23155766
(Bright)
23155767

N/A

23154829

20961913

CX/CH

Day Cab

Single
Outlet
Right Side
Inboard

(Not
Bright)
23155769
(Bright)
23155770

N/A

23154829

20961913

Page
2(6)

Mack Trucks
Field Service Bulletin

Date
11.2018

Group

No.

Release

284

069

01

GU7

Day Cab

Dual
Outlet

(Not
Bright)
23155776
(Bright)
23155777

(Not
Bright)
23189087
(Bright)
23189089

23154829

20961913

CX/CH/
GU8

Day Cab

Dual
Outlet
Outboard

(Not
Bright)
23155779
(Bright)
23155780

N/A

N/A

N/A

CX/CH

Day Cab

Dual
Outlet
Inboard

(Not
Bright)
23155782
(Bright)
23155783

N/A

N/A

N/A

All

All
Sleepers

All

(Not
Bright)
23154798
(Bright)
23154799

N/A

N/A

N/A

Twin Steer
GU7
GU8

All

All

(Not
Bright)
23181996
(Bright)
23181995

N/A

N/A

N/A

Model

Exhaust
Configuration

Pipe Part Number

GU8

Cab Mounted
Vertical Stack

23155787

GU7

Cab Mounted
Vertical Stack

23155789

23204566

Page
3(6)

Mack Trucks
Field Service Bulletin

Date
11.2018

Group

No.

Release

284

069

01

Instructions
1 Decommission the vehicle. Install wheel chocks and disconnect the battery.

W7086748

W3086747

2 Remove the PM sensor and module.
3 Remove all exhaust pipes up to the SCR outlet pipe.
4 Pressure wash the inside of each pipe that will be reused.
5 Reassemble the exhaust system using the new parts referenced in the table above.
6 Mark the SCR outlet pipe 1.5" from the end also mark the new pipe (not flex) 1.5" from its
inlet.
7 Slip the flex pipe as for over the SCR outlet pipe as possible.
8 Install the new exhaust pipe.
9 Using a new clamp assemble the new exhaust pipe to the new flex pipe using the 1.5"
mark to get the correct amount of overlap.
10 Slide the assembly into place using the 1.5" mark on the SCR outlet as a reference point
and to ensure the correct amout of overlap, once in both pipes are in place use clamps to
secure.
Note: Correct installation is achieved when the flex pipe is in a "relaxed" state, there
should be no compression or expansion visible on oposing sides of the pipe after
installed.
11 Install the new PM sensor and module.
Note: Do not use any lubricant of any kind on the PM sensor threads.
Note: Align the tab on the sensor with the slot.
12 Torque the sensor to 35 +/- 5 Nm (26+/- 4 Ft lb)
13 Install the sensor module.
14 Torque the nuts to
M6: 10 +/- 5 Nm (88 +/- 3 in lb)
M8: 24 +/- 4 Nm (17.1 +/- 3 ft lb)
15 Install the wire ties and clamps.
Note: Use high temperature cable ties.

Page
4(6)

Mack Trucks
Field Service Bulletin

Date
11.2018

Group

No.

Release

284

069

01

16 Connect the battery.

W3086758

17 Clear any DTC codes.
18 Remove the wheel chocks.

W7086759

Page
5(6)

Mack Trucks
Field Service Bulletin

Date
11.2018

Group

No.

Release

284

069

01

Reimbursement
This repair may be eligible for reimbursement if a
product failure was experienced within time and mileage
limits of the applicable Warranty coverage.
Reimbursement is obtained via the normal claim
handling process.

UCHP
Reimbursement

Claim Type (used only when uploading from the Dealer
Bus. Sys.)

W

Labor Code
Primary Labor Code (Exhaust Particulate Sensor, Repair)

2846-16-09-01
See table for times.

Causal Part

22946032

Labor Times Reference – 2017 Vehicles
Model

Cab Type

Exhaust
Configuration

Pipe 1 Part Number

CX/CH/GU8

Day Cab

Single Outlet Right
Side Outboard

1.5 hr

GU7

Day Cab without
Transmission
Plate

Single Outlet Right
Side Inboard

1.5 hr

GU7

Day Cab with
Transmission
Plate

Single Outlet Right
Side Outboard

1.5 hr

CX/CH

Day Cab

Single Outlet Right
Side Inboard

1.5 hr

GU7

Day Cab

Dual Outlet

2.9 hr

CX/CH/GU8

Day Cab

Dual Outlet Outboard

2.9 hr

CX/CH

Day Cab

Dual Outlet Inboard

2.9 hr

All

All Sleepers

All

2.8 hr

Twin Steer GU7 &
GU8

All

All

1.7 hr

GU7

Cab mounted vertical
stack

1.2 hr

GU8

Cab mounted vertical
stack

1.2 hr

Page
6(6)