NHTSA ID Number: 10044247
Manufacturer Communication Number: FSB-255-023
TSB/Document Date: 2012-05-24
Summary
MACK TRUCKS
: SEVERE FRETTING DAMAGE OF THE ENGINE VARIABLE GEOMETRY TURBOCHARGER ACTUATOR (ENGINE VGT ACTUATOR) HARNESS AND TURBINE SHAFT SPEED SENSOR (TSS) CONNECTORS MAY CAUSE AN UNRELIABLE SIGNAL TO THE ENGINE VGT ACTUATOR. ALSO INCLUDED MODEL CMM AND CMH. NO MODEL YEARS GIVEN. *JS
Field Service Bulletin
Trucks
Mack Trucks, Inc.
Greensboro, NC USA
This Field Service Bulletin replaces
bulletin, “FSB 255-023, SRA and
TSS Connector Pin Replacement”,
PV729–FSB255-023_M (USA52909)
dated (04/2012).
Date
Group
No.
Release
Page
4.2012
255
023
02
1( 8 )
Connector Pin, Replacement
CHU, CXU, GU, LEU, MRU, TD, CMM, CMH
MP7, MP8, MP10
SB-10044247-9335
FSB 255-023, Connector Pin, Replacement
(April 2012)
Severe fretting damage of the Engine Variable Geometry Turbocharger Actuator (Engine
VGT Actuator) harness and Turbine Shaft Speed Sensor (TSS) connectors may cause an
unreliable signal to the engine VGT Actuator on certain MACK CHU, CXU, GU, LEU, MRU,
TD ,CMM, and CMH trucks. An unreliable signal to the engine VGT Actuator will generate
Diagnostic Trouble Codes (DTCs). If DTCs are logged and pin fretting is identified as the
cause, the engine VGT Actuator and TSS connector pin and socket contacts should be
replaced. Replacement of the pin and socket contacts will eliminate pin fretting and increase
the reliability of the signal to the engine VGT Actuator.
Note: This bulletin also applies to MACK Trucks Australia.
W2072541
PV729-FSB255-023_M
USA53286
Mack Trucks, Inc.
Field Service Bulletin
Date
4.2012
Group
No.
Release
255
023
02
Required Parts
Connector Pin Replacement Parts
Item #
Part Number
Description
Crimp Jaw Position
1
984945
Pin, Eng VGT Actuator Conn
B
2
3963409
Socket, Eng VGT Actuator Conn
B
3
984946
Pin, TSS Connector
A
4
11039671
Socket, TSS Connector
A
5
20734499
Wire Seal, Eng VGT Actuator Conn
N/A
6
25325008
N/A
Item #
Part Number
Description
1
9808646
Extraction Tool, Engine VGT Actuator Connector
2
9809774
Extraction Tool, TSS Connector
3
88890003
Crimp Pliers
4
88890004
Crimp Jaw
Connector Pin Replacement Tools
Procedure
You must read and understand the precautions and guidelines in Service Information,
group 20, "General Safety Practices, Engine" before performing this procedure. If you
are not properly trained and certified in this procedure, ask your supervisor for training
before you perform it.
1 Raise the cab or hood.
2 Disconnect all cables from the negative (ground) battery terminals to prevent personal
injury from electrical shock and prevent damage to electrical components.
3 Disconnect both harness couplers.
Note: The connectors shown are for reference only. Your actual configuration may be
different, depending on truck model and components.
Note: In the event the connectors or harnesses are damaged, replace engine VGT
Actuator component connector (Item 1, Figure below) with part number 984944, engine
VGT Actuator engine harness connector (Item 2) with part number 3963412, and replace
TSS engine harness connector (Item 3) with part number 984849. The TSS component
connector (Item 4) is not available as a replacement item. Replace the TSS component
connector as an assembly (see IMPACT for the appropriate part number). Additionally,
plug seal part number 970771 is required to seal any unused pin and socket locations of
the connector housings.
Page
2( 8 )
Mack Trucks, Inc.
Field Service Bulletin
Date
4.2012
Group
No.
Release
255
023
02
4 Remove harnesses from the mounting bracket.
W2072542
.
5 Remove the conduit clamps from both harness sections.
Note: The engine VGT Actuator harness connector is shown for reference only. The
procedure is the same for the TSS harness connectors.
W2072543
Page
3( 8 )
Mack Trucks, Inc.
Field Service Bulletin
Date
4.2012
Group
No.
Release
255
023
02
6 Using extraction tool 9808646 or 9809774, remove the defective pins from the connectors.
Note: Before removing terminals, note and document pin locations for reassembly
purposes.
W2072544
7 Cut and remove old pins from the harnesses.
W2072545
Page
4( 8 )
Mack Trucks, Inc.
Field Service Bulletin
Date
4.2012
Group
No.
Release
255
023
02
8 Assemble the wire and the appropriate wire seal as shown in figure below.
W2072546
9 Using a suitable wire stripper, strip 5 mm (0.2 in) of insulation from the end of each wire.
W2072547
10 Pre-assemble the appropriate pin or socket contact with stripped wire and seal.
W2072548
Page
5( 8 )
Mack Trucks, Inc.
Field Service Bulletin
Date
4.2012
Group
No.
Release
255
023
02
11 Using crimp pliers 88890003 and crimp jaw 88890004, crimp the pin or socket contact.
Note: See table on page 1 for the proper crimp jaw position.
W2072549
12 Insert the crimped pin or socket in the correct position of the connector.
W2072550
Page
6( 8 )
Mack Trucks, Inc.
Field Service Bulletin
Date
4.2012
Group
No.
Release
255
023
02
13 Install the conduit clamps.
W2072543
14 Install the harnesses onto the bracket and secure.
15 Connect the harnesses.
W2072542
16 Reconnect all previously removed cables to the negative (ground) battery terminals.
17 Lower the cab or hood.
Page
7( 8 )
Mack Trucks, Inc.
Field Service Bulletin
Date
4.2012
Group
No.
Release
255
023
02
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.
Claim Type (used only when uploading from the Dealer Bus. Sys.)
W
Labor Code
Primary Labor Code for engine VGT Actuator or TSS Harness Pins
Replacement
2732C-01-80
0.7 hrs.
Causal Part
984945
MACK Trucks North America engages in a continuous program of testing and evaluating to
provide the best possible product. MACK Trucks North America, however, is not committed
to, or liable for updating existing chassis.
Page
8( 8 )
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TSB/Document ID: FSB-255-023
Replacement Service Bulletin Number:
MFR Communication Date: 2012-04-01
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE AND ENGINE COOLING:ENGINE
MFR Component System:
MFR Component Subsystem:
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