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SS 3124 - FTL 2023 M2 Bulkhead Module
Replacement and DiagnosticLink Issues 8

Applicable Vehicles

Legacy M2 Business Class, 108SD, 114SD using a Bulkhead Module (BHM) and Chassis Module (CHM)
for power distribution and control.

Production vehicles may have used any of approximately 10 different part numbers.

Currently-available replacement BHM parts include:

1. 06-75157-001 ("pre-2016 OBD"), version 7.30 software

2. A66-03086-001 (automatic baud rate detection for J1939), version 7.43 software
3. A66-03086-002 (fixed 250kbps J1939 baud rate), version 7.45 software

4, A66-03086-003 (fixed 500kbps J1939 baud rate), version 7.44 software

Symptoms

Inability to program a replacement BHM with the per-serial configuration using DiagnosticLink
Professional. Although DiagnosticLink may report success, the VIN in the replacement part is
(usually) the "blank" VIN of ABCDEFGHIJKLMNOP'1.

See the attached screen shot, which shows the DiagnosticLink Professional view of a BHM with
part number 06-75157-001 (originally loaded with 7.30 application software) that was reflashed to
7.45 application software and has the blank VIN.
Issue

When replacing the BHM, Excelerator must be consulted to determine the correct replacement
part for the serial number that is being serviced.

This is especially important if a truck is being rebuilt with a sales cab, as sales cabs may not have
the correct BHM for the original vehicle. Use the serial number of the original vehicle when
confirming the correct BHM part number.

If an incorrect BHM (per the pats catalog) is used, there are several issues that arise when using
DiagnosticLink Professional to configure the BHM:

1. DiagnosticLink Professional will not flash the per-serial configuration to the module.

2. As aresult of the failure to flash the per-serial configuration, the VIN in the BHM will remain
at "ABCDEFGHIJKLMNOP"".

3. DiagnosticLink will set the vehicle data to an (incorrect) software version.

4. Without further intervention by the DTNA CAC, further attempts to install a BHM will also fail.

5. Even if the correct BHM part is subsequently installed, DiagnosticLink professional will
reprogram the application software, rendering the BHM unusable except on newer M2
chassis.

The BHM "upgrade" path has been split into 3 defined "breakpoints" for BHM software and
parameter compatibility. These breakpoints are not correctly enforced with DiagnosticLink.

1. BHM 7.30 software is compatible with a//M2 chassis built before 2016 OBD changeover (2
January 2016) for the U.S. and Canada, and may have also been used on vehicles for export
markets. See below for more information. Part number 06-75157-001 replaces all M2 BHM
parts for older M2 chassis.

e Allolder M2 chassis canbe updated to the 7.30 software without issue. Parameter
interchange and compatibility has been confirmed.

e There is no upgrade pathto newer software versions (7.4x) - parameter interchange
and compatibility is not defined.

2. BHM 7.45 software is compatible only with M2 chassis built after 2016 OBD changeover (2
January 2016) where the truck uses a 250kbps J1939 datalink (BLACK diagnostic connector).
Part number A66-03086-002 replaces all other automatic baud rate detecting BHM modules
for these chassis.

e Trucks with 7.41 or 7.43 software anda 250kbps J1939 datalink can be updated to this
software version.
e This software is not compatible with trucks that used BHM 7.30 or earlier software.
e This software is not compatible with trucks that used BHM 7.44 software, the BHM will
prevent communication on the J1939 network.

3. BHM 7.44 software is compatible only with M2 chassis built after 2016 OBD changeover (2
January 2016) where the truck uses a 500kbps J1939 datalink (GREEN diagnostic connector).
Part number A66-03086-003 replaces all other automatic baud rate detecting BHM modules
for these chassis.

e Trucks with 7.41 or 7.43 software anda 500kbps J1939 datalink can be updated to this
software version.

e This software is not compatible with trucks that used BHM 7.30 or earlier software.

e This software is not compatible with trucks that used BHM 7.45 software, the BHM will
prevent communication on the J1939 network.

NOTE: the 2 January 2016 changeover date represents the date when the automatic baud rate
detecting BHM changed over in production for trucks that complied with the 2016 HD-OBD
regulation changes for the U.S. and Canada. Some trucks built in 2016 may have used the fixed baud
rate module, therefore, this is notan "absolute" date. Vehicles built for Mexico and export markets
did not adopt a 500kbps J1939 datalink at the same time, and BHM version 7.30 remained in
production until July 2017. Excelerator will list the correct BHM replacement for each truck serial
number.

Solution

Before using DiagnosticLink, ensure that the correct BHM part number, as called out in
Excelerator, is installed on the truck. Excelerator has correct part number information for the BHM
(module 32A).

If a module has been replaced, and it is determined that the module was flashed with incorrect
software, DiagnosticLink has initiated a migration(the term that was coined to indicate a software
upgrade). A ticket must be logged with the Customer Assistance Center in SalesForce, specifically
requesting BHM migration rollback.

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Khoros <
BHM_J1939 - Bulkhead Module

Device Configuration
Software Mode Running in Application

Device Information

Make FRGHT

Model BHM_L

Serial Number 504055

Hardware Revision AO

Software Indentification U.r.2.A0.07.45

VIN ABCDEFGHUKLMNOP1
ID Block

Diagnostic Version 745

' sean BH
li ig = 4
“tn Lo

JOHN BEEHEE ELECTRO

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