23-NA-135

Bulletin No.:
Service Bulletin
Date:
23-NA-135
August, 2023
INFORMATION
Subject:
Brand:
Information on Oil Level Control Changes and Compatibility on 2023-2024 9-Speed
Transmissions
Model:
Enclave
Buick
Encore
Envision
Model Year:
from
to
2023
2023
2024
2024
XT4
Cadillac
XT5
Chevrolet
Trailblazer
Traverse
GMC
Acadia
Terrain
to
Engine:
Transmission:
M3W
M3F
M3H
M3H
2024
2024
XT6
Blazer
VIN:
from
M3G, M3W
M3G, M3W
2024
2024
2023
2023
2024
2024
M3T, M3V
M3F
M3V
M3G, M3W
M3U
Involved Region or Country
North America, Europe, Kazakhstan, Uzbekistan, Russia, Middle East, Israel, Palestine,
Bolivia (West), Chile (West), Colombia (West), Japan, Cadillac Korea (South Korea), GM
Korea Company, China - SGM, Taiwan, Australia/New Zealand, Other Africa
Information
The purpose of this bulletin is to inform the Service Department Personnel about an
update to the GM 9-speed transmission automatic transmission fluid level control system.
The purpose of the system is to store fluid in the side cover as the transmission
warms up.
The system used from the beginning of the 9-speed transmission thru 2023 consists of:
• standpipe with a thermal door
• on/off solenoid
• valve
The changes to the system starting with 2024 MY and some 2023 models with the RPO
BCE are described below.
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.
Copyright 2023 General Motors LLC. All Rights Reserved.
Page 2
August, 2023
Bulletin No.: 23-NA-135
Additional Information
6397367
6396977
The previous a/trans fluid level control valve (1) on the
stall pipe (item #21) had a small thermal door. The new
style can be recognized by the larger thermal door (2)
on the stall pipe.
The valve body to transmission case spacer plate is
covering over the port (item #456).
6397498
The solenoid body will eliminate the a/trans fluid control
solenoid (item #403).
6396979
The valve body will eliminate the a/trans fluid valve
(item #437).
Bulletin No.: 23-NA-135
August, 2023
Page 3
The previous style valve body cover (1) did not have a
plug hole in it. The new style cover (2) will have a plug
and should not be removed as it is used by the
assembly plant.
When servicing these transmission components, the
technician must use the parts that are specified in EPC
for the MY vehicle being repaired. There is a possibility
the components for a 2024 vehicle may be the old style.
This is not a concern or a mis-build, this is to facilitate
the manufacturing process. This is possible because
the 2024 and 2023 RPO BCE transmission calibration
ignores those component inputs.
The exception to this is the new large door standpipe
and the new valve body cover which must be used on
2024 MY and 2023 RPO BCE can be used to service
2023 and prior MY transmissions, but are necessary on
2024 MY and 2023 RPO BCE.
6397499
The a/trans wiring harness will eliminate the wire for the
a/trans fluid control solenoid (item #31).
6397504
Version
1
Modified
Released July 31, 2023
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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