23-NA-139

Bulletin No.:
Service Bulletin
Date:
23-NA-139
October, 2023
INFORMATION
Subject:
Information on Internal Transmission Faults Related to Components Not Serviceable at
Dealer Level, Service Transmission Message Displayed on Driver Information Center
(DIC), Malfunction Indicator Lamp (MIL) Illuminated – DTC P1955 and/or P0867 Set
This service bulletin replaces PIP5797E. Please discard PIP5797E.
Brand:
Model:
Chevrolet
Corvette
Model Year:
VIN:
from
to
from
to
2020
2023
—
—
Engine:
Transmission:
All
All
Involved Region or Country
North America, Europe, Middle East, Australia/New Zealand
Condition
Some customers may comment on one or more of the following:
• MIL illuminated.
• Service Transmission Message displayed on the DIC.
Technicians may find one or more of the following DTCs set in the transmission Control
Module (TCM):
• P1955
• P0867
Cause
Internal transmission faults related to components not serviceable at the dealer level.
Correction
If DTCs P1955 or P0867 are current or in history, the transmission assembly will require
replacement. Do not attempt any other repairs for these DTCs other than transmission
assembly replacement following service information and labor times.
Note: An MCV replacement will not repair vehicles with P0867 or P1955 current or in
history.
Copyright 2023 General Motors LLC. All Rights Reserved.
Page 2
October, 2023
Bulletin No.: 23-NA-139
Important: Service agents must comply with all
International, Federal, State, Provincial, and/or
Local laws applicable to the activities it performs
under this bulletin, including but not limited to
handling, deploying, preparing, classifying,
packaging, marking, labeling, and shipping
dangerous goods. In the event of a conflict between
the procedures set forth in this bulletin and the
laws that apply to your dealership, you must follow
those applicable laws.
Warranty Information
For vehicles repaired under the Emission coverage,
use the following labor operation. Reference the
Applicable Warranties section of Investigate Vehicle
History (IVH) for coverage information.
Labor
Operation
Description
Labor Time
8486338*
Perform Diagnostics and
Reset Codes P1955 and/or
P0867
0.2 hr
*This is a unique Labor Operation for bulletin use only.
Version
2
Modified
Released August 09, 2023
Revised September 26, 2023 – Removed the first Note in the Correction section.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
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