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 SS 3124 - FTL Legacy M2 Bulkhead Module (BHM) Repl...

SS 3124 - FTL Legacy M2 Bulkhead Module (BHM)
Replacement and DiagnosticLink Issues 
PLEASE NOTE: Attached is a document "Bulkhead Programming Instructions" that should be
used when programming the new BHM. For additional information on migrating the bulkhead
module please see the M2 workshop manual section “flashing the bulkhead module procedure"

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
After replacing the BHM in a truck without first confirming the correct part with Excelerator,
DiagnosticLink may not be able to program the replacement BHM. Although DiagnosticLink may
report success, the VIN in the replacement part is (usually) the "blank" VIN of
ABCDEFGHIJKLMNOP1.

If an incorrect part is used, and then the correct part is installed, DiagnosticLink may program an
incorrect software version to the module. 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 a blank VIN.

Flashing to a different software version than supported by the module may render a BHM
inoperative. The example noted above resulted in a module that would only communicate on a
500kbps J1939 network, where the truck had a Natural Gas engine that only supported a 250kbps
J1939 network.

NOTE: There are other known situations where a replacement BHM cannot be programmed. If the
replacement part was confirmed before any programming attempt, this Service Solution likely will
not apply.

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. 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, as noted
above.
2. As a result of the failure to flash the per-serial configuration, the VIN in the BHM will remain at
"ABCDEFGHIJKLMNOP1".
3. DiagnosticLink will attempt to migrate 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.

At least two instances where a dealer has rendered multiple BHM parts unusable have been
reported.

Sometime after calendar year 2017, three different BHM "upgrade" paths were defined. Prior to that
time, any BHM with newer software could be installed on an older truck without issue. That is no
longer true - the following defined "breakpoints" for BHM software and parameter compatibility are
enforced in the FLT mainframe. However, these breakpoints are not correctly enforced with
DiagnosticLink.

1. BHM 7.30 software is compatible with all 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.
All older M2 chassis can be updated to the 7.30 software without issue. Parameter
interchange and compatibility has been confirmed.
There is no upgrade path to newer software versions (7.4x) - parameter interchange and
compatibility is not defined.
2. BHM 7.43 software is compatible with approximately the first 2 years of 2016 OBD production
(2 January 2016 changeover). New module part number is A66-03086-001.
Version 7.43 software can be flashed to a BHM that has 7.41 software without any loss of
functionality.
Although theoretically possible, upgrades to either the 7.44 or 7.45 software
are blocked because the boot loader
3. BHM 7.45 software was changed over on 18 January 2021 and is compatible only with M2
chassis built for export markets or with an engine exempt from HD-OBD regulations. Part
number A66-03086-002.
Trucks with a 7.41 or 7.43 Bulkhead Module and a 250kbps J1939 datalink CANNOT be
updated to this software version. The application is not compatible with the boot loader
used on earlier modules and upgrades are blocked.
This software is not compatible with trucks that used BHM 7.30 or earlier software.
This software is not compatible with trucks that used BHM 7.44 software, the BHM will
prevent communication on the J1939 network.
4. BHM 7.44 software was changed over on 18 January 2021 and is compatible only with M2
chassis built after that date. This version is a fixed 500kbps baud rate J1939 module, intended
to address some of the issues caused by the automatic baud rate detecting modules
(versions 7.41 and 7.43). Part number A66-03086-003.
Trucks with 7.41 or 7.43 software and a 500kbps J1939 datalink CANNOT be updated to
this software version.
DiagnosticLink may offer software version 7.44 as a software upgrade. Efforts are
underway to prevent this from occurring.

The 7.44 application software is not compatible with the boot loader used on the
7.41 and 7.43 version BHM modules.
This software is not compatible with trucks that used BHM 7.30 or earlier software.
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 (version 7.41) changed over in production for trucks that complied with the 2016 HDOBD regulation changes for the U.S. and Canada. Some trucks built in 2016 may have used the
version 7.30 fixed baud rate module, therefore, this is not an "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 data migration. A ticket must be logged with the Customer
Assistance Center in SalesForce, specifically requesting BHM migration rollback.
Labels :
108SD

114SD

Electrical

M2

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Attachments
 
 BHM_Programming_Instructions.docx 



7 Kudos

Comment

Vehicles Affected: Legacy M2 Business class, 108SD and 114SD

Described Condition:
If replacing a Bulkhead Module, refer to Excelerator for the latest hardware displayed in
module 32A. If the BHM was replaced in a truck without first confirming the correct part
with Excelerator, DiagnosticLink may not be able to program the replacement BHM.

Figure 1
This is especially important if a truck is being rebuilt with a sales cab. 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.

Figure 2
Confirm vehicle specific part number in module 32A in Excelerator.

Below is the Bulkhead Module Programming Instructions that should be used when
programming the new BHM

New BHM Migration programming Steps:

Once you are connected to the vehicle and in the add request screen it should auto
populate the ECU. If it defaults to all A’s for the VIN or alphabetical sequence 1 then type in
the full VIN for the migration. Verify the hardware part number matches the installed BHM.
(if you are replacing the BHM then validate that the hardware part number matches with the
correct one in Excelerator).

Figure 3

Once you click on connect to server and the “download completes” click on the VIN
number and hit next.

Figure 4

Figure 5

Click connect.

Figure 6
If programming BHM to the same version, use the latest file. If replacing BHM and version
listed in Excelerator is different than what was on the vehicle select newest.

Figure 7

Confirm your target is your desired version and VIN, press start.

After completing the process in the identification tab confirm the VIN, Software
identification and the diagnostic version is correct.

Figure 8