Revisions to this document are noted
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SUBJECT:

SIL 34-1K2K-19, Rev. A
January 06, 2020
Page 1 of 4

P2789 Clutch Adaptive Learning at Limit

MODELS AFFECTED:

1000/2000 SeriesTM Transmissions

NOTE: Reimbursement for this repair is limited to transmissions in the original warranty period or
Extended Transmission Coverage, if applicable.

Description of Complaint:
In some low mileage vehicles, the Check Transmission lamp may illuminate along with setting DTC P2789
Clutch Adaptive Learn at Limit. The C1 clutch may show as “Not OK” in the Trans Health Indicator section of the
“Prognostics” tab in the Allison DOC® software, Figure 1 and Figure 2.

Figure 1. Trans Health Indicator Section

Figure 2. Transmission Health Indicator

WBD / SL8626EN

4908309

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

SIL 34-1K2K-19, Rev. A
January 06, 2020
Page 2 of 4

Service Channel Procedure:
When the Check Transmission lamp illuminates due to DTC P2789, perform the diagnostic steps as outlined
in the Troubleshooting Manual, TS7138.
If this issue is not resolved after following the diagnostic steps in TS7138, then reprogram the TCM by performing
the following steps:
1. Connect to the TCM with the Allison DOC® software to determine the TCM software level, Figure 3. If the
software is B191 or newer, an update is not required for resolution. If the software level is prior to B191,
proceed to step 2.

Figure 3. TCM Software Level
2. Using the TCM Serial Number (S/N), download the B191 or newer calibration.
3. Select the calibration in the Calibrations to Load into ECU/TCM window at the bottom of Allison TCM
ReflashTM, select Load refer to Figure 4.

Figure 4. Allison TCM ReflashTM Calibrations to Load into ECU/TCM

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

SIL 34-1K2K-19, Rev. A
January 06, 2020
Page 3 of 4
4. The Load Report form, Figure 5 will appear

Figure 5. Allison TCM ReflashTM Load Report Form Window
5. In the top of the New Calibration section, Figure 6 if the Calibration ID begins with B191 or newer, load
the calibration into the TCM.
NOTE: If the calibration is earlier than B191, the software level for specific TCM is being held to an
older level. In this case, contact [email protected] to request an update
to B191 or newer calibration.

Figure 6. Top of the Load Report Form
6. Once the TCM has been successfully reprogrammed, connect with the Allison DOC® software and confirm
that B191 or newer was loaded.
If after loading the B191 or newer calibration into the TCM does not resolve the P2789 issue, call the Allison
Technical Assistance Center, TAC 1-800-252-5283

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

SIL 34-1K2K-19, Rev. A
January 06, 2020
Page 4 of 4

Warranty Claim Submittal:
Authorized Allison Service Outlets shall submit an AWAARE claim type 1 for each vehicle completed under this
SIL. Any additional work shall be claimed separately, even if performed simultaneously with another transmission
repair, e.g., overhaul solenoid replacement, etc.
AWAARE Claim Values
Claim Type

1

Authorization Number

Attach copy of this SIL to the claim

Special Activity Number

SIL 34-1K2K-19

Primary Failed Part

400

Complaint Code

FS10

Failure Code

BA04

AWAARE Claim Labor Times
Labor Operation Code

Labor Hours

Labor Operation Description

096501

1.0

TCM Recalibration and Verify

096400

0.5

Test Drive

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