Service Bulletin

Bulletin No.:

17-NA-066

Date:

July, 2023

INFORMATION
Subject:
Brand:

Information on Automatic Transmission Oil Cooler Flush and Flow Test
Model:

Model Year:
from

to

VIN:
from

to

—

—

Engine:

Transmission:

—

Equipped with
Automatic
Transmission

Buick
Cadillac
Chevrolet

GM Passenger Cars
and Light/Medium
Duty Trucks

2024 and Prior

GMC

Involved Region or Country

North America

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.
The J-45096 TransFlow machine is a valuable GM
Essential Tool for diagnosing transmissions that have
been subject to potential overheating or lack of
lubrication.
J-45096 Use and Maintenance
Important: Please refer to the TransFlow Operation
Manual for complete information regarding
specifications, set-up, operating instruction,
maintenance, and troubleshooting.
Dealers must only use the appropriate GM automatic
transmission fluid when doing a repair on a GM
transmission. If the fluid in the J-45096 TransFlow
machine is different from what is used in the
transmission, after performing the flush and flow test,
use compressed air to blow the residual transmission
fluid out of the oil cooler and lines
It is recommended to perform a self-test after initial
set-up or at any time you are experiencing issues with
the J-45096. The self-test takes minutes and will
ensure the tool is operating correctly and that the shop
air supply maintains a minimum of 90 psi (621 kPa)
when connected to the tester.

Copyright 2023 General Motors LLC. All Rights Reserved.

The Automatic Transmission Fluid (ATF) in the supply
vessel of J-45096 must be greater than 65°F (18°C) in
order for J-45096 to operate properly. During the colder
winter months, you may want to consider some of these
suggestions to keep the ATF at 65°F (18°C) or higher:
• Store the J-45096 in an area of the dealership
where the room temperature remains at or above
65°F (18°C) when not in use.
• Do not attempt to increase the fluid temperature in
the J-45096 with an engine oil dipstick, or any
other immersion type heater. J-45096 has a check
valve in the supply reservoir. Inserting a heater will
damage the check valve and the subsequent
repair expense would be the dealer's
responsibility.
• Keep the ATF level in the reservoir low when the
J-45096 is not in use. Store several gallons of ATF
in an area where the temperature is maintained at
or above 65°F (18°C). Fill the reservoir of the
J-45096 as needed before using the machine on
each repair.
• With the ATF in a tightly sealed container, place
the container in a tub of hot water for a period of
time. Then pour the ATF into the reservoir.
• Place the J-45096 in the direct sunlight in cooler
weather with the cabinet door open to expose the
reservoir to the rays of the warm sun.
• A heater blanket, P/N J-45096-10, is available for
the J-45096. This heater fastens around the
Transflow® internal supply vessel and runs on 110
volts AC. The heater will warm the ATF in the
supply vessel to at least 65°F (18°C) and has a
thermostat to hold a constant temperature.
The required minimum ATF oil flow rate reading is
directly related to the supply oil temperature. Refer to
the TransFlow Operation Manual for the ATF flow
specification based on the temperature of the ATF in
the supply vessel.

Page 2

July, 2023

Bulletin No.: 17-NA-066

When performing the flow test, if the flow rate is under
the minimum amount specified in the Transflow
Operation Manual for the type of cooler line used, and
you have verified that there is sufficient shop air supply
at the tester (minimum 90 psi (621 kPa)), additional
repairs are likely necessary to fix the cooling system
restriction (i.e. TOC replacement, line replacement,
etc.) and a second flow test must be completed to
validate the repair.
Important: The tool was calibrated for maximum flow
rates of approximately 2 gallons per minute (GMP) (7.6
L/min) with room temperature fluid. If the flow rates
higher than 2.5 GPM (9.5 L/min), the J-45096 may be
malfunctioning or not set up correctly. Perform a
TransFlow self-test as outlined in the operator’s manual
for initial diagnosis. Warranty Claim submissions with
flow rates higher than 2.5 GPM are subject to review.
The technician should perform a TransFlow self-test as
outlined in the TransFlow Operation Manual for initial
diagnosis and re-test if they receive a flow rate of
greater than 2.5 GPM (9.5 L/min).

Warranty Information
GM does not require a cooler flush and flow test to be
performed in every instance of transmission or torque
converter replacement/repair. However, a cooler flush
and flow test may be appropriate and/or recommended
by TAC for diagnosing transmissions that have been
subject to potential overheating or lack of lubrication.
If performing a cooler flush and flow test, technicians
should document the Flow Code from the J-45096
Transflow machine in the “Correction” comments of the
job card. The code is displayed on the J-45096 after
completion of the flow test and flush when the dial is in
the CODE position, and is seven or eight
characters long.
Fluid: The actual amount of ATF used for the flush
portion of the repair must be submitted in the Parts
section of the warranty transaction. Submit the part
number of the ATF used (quart, gallon, drum or bulk
part number), and enter a quantity of 1 for each quart
consumed (max 8 quarts or 8 L) in the Part Quantity
field.
Version

6

Modified

Released March 09, 2017
Revised May 10, 2017 – Added a bullet for the Bolt/Bolt EV under Special Cases.
Revised December 14, 2018 – Added U.S. Only to Subject, 2019 Model Year, a Note at
beginning of bulletin and updated J-45096 Use and Maintenance section and Warranty
Information.
Revised May 18, 2022 – Updated information under J-45096 Use and Maintenance.
Revised June 29, 2023 – Updated Subject, added the 2020-2024 Model Years, added an
Involved Region or Country table and bulletin is now applicable to North America, added
first Important statement and removed Warranty Information.
Revised July 21, 2023 – Removed the Note at beginning of bulletin, added and clarified
Warranty Information, and removed Flow Code 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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