18-NA-035

Bulletin No.:
Service Bulletin
Date:
18-NA-035
January, 2024
INFORMATION
Subject:
Information on Transmission No Command Overdrive Ranges During Cold Ambient
Temperatures
Brand:
Model:
Buick
Cadillac
XT5
Holden
2022
LE2, LUV
MNH
2024
LSY
2018
XT4
2019
from
to
M3H
Cruze (Gen II - B)
2019
LE2
Equinox
2024
LYX, LSD
Malibu
2018
Trax
GMC
Transmission:
(Automatic)
Encore
2020
VIN:
Engine:
to
XT6
Chevrolet
Model Year:
from
Acadia
2020
Terrain
Equinox
Trax
2018
2019
—
—
LFV
M3G
MNU
MNH
2022
LE2, LUV
2023
LSY
M3G
2024
LYX, LSD
M3U
2020
1.5L
1.4L
6-Speed
Involved Region or Country
North America, Brazil, Colombia, Ecuador, Chile, Uruguay, Peru, Paraguay, Argentina,
Europe, Middle East, Israel, GM Korea Company, China, Australia/New Zealand, Egypt,
South Africa
Condition
Some customers may comment that the transmission will not shift into overdrive range
during cold ambient temperatures.
This condition may be caused by the engine control system detecting conditions that
indicate the freezing of moisture in the charge air cooler.
Note: Diagnostic aid overdrives ranges can only be commanded with GDS tool to
confirm correct transmission operation.
Information
When the control system detects the above conditions and the ambient temperature is
either below -10°C (14°F) or slightly above -10°C (14°F) with high moisture, but not
frozen, it takes the following actions:
• Requests a lower gear than normal (resulting in higher RPM).
• The system will enable the condition as needed to prevent freezing.
⇒ This strategy is to prevent a potential excessive air restriction due to an icing
condition, which would lead to a P0299 DTC and reduced engine
power mode.
Explain to the customer that their vehicle is operating normally.
Do not attempt to repair or replace any parts to alter the original vehicle design intent.
You may wish to give the customer a copy of this bulletin.
Copyright 2024 General Motors LLC. All Rights Reserved.
Page 2
January, 2024
Bulletin No.: 18-NA-035
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.
Version
7
Modified
Released February 2, 2018
Revised February 12, 2018 – Updated the temperature readings to 0°C (32°F) and
removed a transmission for the Terrain.
Revised February 21, 2019 – Removed M3U from Equinox, revised the Subject title,
added a Note and temperature slightly above 0°C (32°F) to the Information section.
Revised February 3, 2020 – Added the 2020 Model Year.
Revised February 09, 2021 – Added the Chevrolet and Holden Trax Model, Holden
Equinox, 2021 Model Year to applicable vehicles and updated the Involved Region or
Country section.
Revised February 01, 2023 – Removed Encore (VIN J), added Additional Models, added
2022 and 2023 Model Years to applicable vehicles, updated Involved Region or Country
section and replaced 0°C (32°F) with -10°C (14°F) in Information section.
Revised January 23, 2024 – Added the 2024 Model Year to Applicable Models.
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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