2022FA04
June 10, 2022
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SUBJECT:

6th Generation TCM Recalibration

MODELS AFFECTED:

1000, 2000, 3000, 4000 Series Transmissions with 6th Generation Controls and Allison
TerraTranTM

Introduction:
Allison Transmission has identified concerns limited to B, C, or N221 and B, C, or N222 software levels:
• Transmission Control Module (TCM) response to CAN messaging is delayed under certain conditions
of low battery voltage.
• Prognostics fluid change intervals with TES 668® transmission fluid are incorrect.
Refer to the following instructions to identify affected calibrations, perform eligible repairs and submit proper
warranty claims.

Description of Conditions Resolved by this Field Action
6th Generation TCMs with B, C, or N221 and B, C, or N222 software are subject to the conditions described below:
• If the battery voltage drops below ~6V without dropping below ~4V and subsequently increases to greater
than ~7V, the reaction of the TCM to CAN messaging will be delayed for the remainder of the key cycle.
• In calibrations with “TES-668 Fluid” set as the “PROGNOSTICS: Transmission Fluid Type”, the Prognostics
fluid change intervals are incorrect. This condition may cause DTC P0897 to set.

Field Action Transmission Identification:
Prior to the repair of an eligible transmission, a Field Action Authorization Number must be obtained by logging on
to https://hub.allisontransmission.com/field-actions. Enter the transmission serial number, VIN, vehicle vocation
code, etc. and request an authorization. If you receive an authorization number, this is confirmation that the field
action has NOT been performed. If the field action has NOT been performed, proceed with the repair as defined.
Include the authorization number in the 4WARDTM Work Performed Comments field prior to submitting the
warranty claim. If you are unable to obtain an authorization number, and you believe the transmission qualifies for
the field action based on the transmission serial number/vehicle model/configuration, contact the Allison Technical
Assistance Center (TAC) at 1-800-252-5283 or 317-242-0700 or email: Allison[email protected].
Once a Field Action Authorization Number has been obtained, confirm that the TCM has B221, C221, N221, B222,
C222 or N222 software. This can be found by connecting the TCM with Allison DOC®. The DTC and General
Info tab will show the Cal ID in the TCM Information section. The first four digits of the Cal ID give the current
software level. If the first four digits of the Cal ID are any of the following, then the software level must be updated:
B221, C221, N221, B222, C222 or N222.

AR / FA8978EN

6135148

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

2022FA04
June 10, 2022
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Figure 1. Current Software Level Example in Allison DOC

Corrective Action Required
If the vehicle is in the affected population, then update software level from B, C, or N221 and 222 to B, C,
or N223 or later by programming based on the TCM serial number in TCM ReflashTM. To receive the latest
software level, it is necessary to check the box labeled “Download Latest Calibration” on the Add screen in TCM
Reflash. After programming is complete, use Allison DOC to verify that the second through fourth digits of the
Cal ID are 223 or later.

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

2022FA04
June 10, 2022
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Figure 2. Updating to Latest Software Level in TCM Reflash
NOTE: The “Download Latest Calibration” option in TCM Reflash should only be used when there is a
specific need to update the software.

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

2022FA04
June 10, 2022
Page 4 of 5

Figure 3. Updated Software Level Example in Allison DOC

Claim Submittal Information:
Approved authorized Allison service outlets must submit work performed per this Field Action as outlined in
Table 1 and Table 2.
Include the Field Action Authorization Number in the 4WARD Work Performed Comments field.

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

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June 10, 2022
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When filing each claim, enter the recalibrated TCM serial number into the Failed Component Serial Number
field of the 4WARD claim.
Table 1. Claim Information
CLAIM TYPE

Automatically Applied by 4WARD system

PRIMARY FAILED PART

Automatically Applied by 4WARD system

SPECIAL ACTIVITY INDICATOR

Not required by 4WARD system

COMPLAINT CODE

Automatically Applied by 4WARD system

FAILURE CODE

Automatically Applied by 4WARD system

FIELD ACTION AUTHORIZATION NUMBER
*Provided from Allison

HUBTM.

*

Must be included in 4WARD Work Performed Comments field.

Table 2. Labor Codes/Hours
LABOR OPERATION CODE

LABOR HOURS

LABOR OPERATIONS

00096501

1.0

RECALIBRATE TCM

00096400

0.5

TEST DRIVE

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.