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May 26, 2020
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SUBJECT:

Incorrect Engine Retarder Selection Calibration Setting in Navistar Vehicles

MODELS AFFECTED:

Navistar Vehicles with 1000/2000 SeriesTM Transmissions with 5th Generation Controls

NOTE: This Tech Tip is in support of Navistar's Service iKNow Article IK1300185. Allison Transmission
locations performing these service instructions should work with their local International® dealer for
reimbursement.

NOTE: This issue is the responsibility of the OEM, and as such will not be repaired under Allison
Transmission, Inc. product Warranty, Partner Coverage, or ETC Coverage.

Background:
Navistar supplied an incorrect Transmission Control Module (TCM) calibration setting for parameter J1939
Reception: EBC1 Engine Retarder Selection [28040]. This incorrect setting prevents the transmission’s Engine
Brake Preselects from functioning. J1939 Reception: EBC1 Engine Retarder Selection [28040] was incorrectly
set to Disabled [0] . The correct value for this parameter in vehicles within this population is Enabled [1]. This
Tech Tip is to support Navistar’s Service iKNow Article IK1300185.

Service Procedure:
1. Confirm the following:
• The vehicle has an ISB engine with engine brake.
• The vehicle has a build date of 11/02/2018 through 10/11/2019.
• The transmission does not downshift to the range specified by the calibration parameter Engine
Brake: Minimum Preselect Range [22020] when the engine brake is active.
If all 3 criteria are met, proceed with this service procedure.
2. Inform the local International® dealer of the complaint and confirm that the International® dealer will
reimburse the Allison shop for this work.
3. Using Allison TCM ReflashTM software, enter the TCM Serial Number or VIN into the 5th Generation Controls
database. Load the calibration into the TCM. The system will correct the calibration setting in TCMs
associated with the vehicles that have been included in the Navistar population.
NOTE: Do NOT use Allison DOC® to upload the calibration file from the TCM prior to reflashing the TCM.
Uploading the file with Allison DOC® will overwrite the corrected parameters in the Allison database.

JC / TT8643EN

4908939

Copyright © 2020 Allison Transmission, Inc. All Rights Reserved.

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May 26, 2020
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4. If internet access was not available when reflashing the TCM, log onto Allison TCM ReflashTM as soon as
internet access is available. Go to the File menu and select Upload Logs to return verification (VER) file(s) to
the Allison database. This will ensure that future service events will use the proper settings.
5. Wait 10 – 20 minutes before proceeding to Step 6. This will ensure adequate time for system processing of
the returned verification (VER) file(s). Since Allison DOC® does not display this parameter, ACCT (Allison
Calibration Configuration Tool), which is available on the Allison HUB, must be used to confirm that the
parameter was set properly during the Allison TCM ReflashTM event.
6. Using ACCT, which can be found in the Engineering section of the Allison HUB, verify that parameter
J1939 Reception: EBC1 Engine Retarder Selection [28040] is set to Enabled [1] on the Calibration
Summary Report.
a. Choose Summary Report from the ACCT Dashboard on the Allison HUB. See Figure 1.

Figure 1. ACCT Dashboard

b. Enter the TCM Serial Number in the Search Value field. Wait for the As of Date field to populate.
Confirm that the As of Date shown is today’s date, indicating that this is the new file just flashed into
the TCM. Then, click Generate HTML. See Figure 2.

Copyright © 2020 Allison Transmission, Inc. All Rights Reserved.

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May 26, 2020
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Figure 2. Summary Report Generation

c. Verify that parameter J1939 Reception: EBC1 Engine Retarder Selection [28040] is set to Enabled
[1] in the Features and Options: Interfaces section of the Calibration Summary Report. Refer to
Figure 3. If it is Disabled [0], proceed to Step 7. If it is set to Enabled [1], proceed to Step 8.

Figure 3. Summary Report Verification

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May 26, 2020
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7. If parameter J1939 Reception: EBC1 Engine Retarder Selection [28040] is set to Disabled [0], then a
new calibration will be required to correct the issue. Submit a change request in ACCT or send the TCM
serial number and a description of the issue to [email protected]. Use the title
“Navistar 28040 Change”. A Calibration Support Service Engineer will provide a Road Ready assembly
number with the correct setting.
a. Using Allison TCM ReflashTM, enter the new Road Ready assembly number as the TCM assembly
number in the 5th Generation Controls database. Load the calibration into the TCM.
b. Repeat Steps 4 through 6
8. Confirm that engine brake preselect downshifts activate upon engine braking, causing the transmission to
downshift to the range specified in calibration parameter Engine Brake: Minimum Preselect Range [22020].
9. If TCMs are going to be removed from vehicles and put into a different vehicle as a part of this action,
then using the Reprogramming feature in Allison DOC®, program the new VIN into the TCM (this can only
be done with the TCM connected to the vehicle).
10. Service Procedure is complete.

Copyright © 2020 Allison Transmission, Inc. All Rights Reserved.