Bulletin No.: 20-NA-136

Service Bulletin

Date: May, 2024

INFORMATION
Subject:

Diagnostic Tips for DTCs Set at a Low Mileage for 9T65 Transmissions

Attention:

The 9T65 Transmission Replacement Pilot Has Ended.

This bulletin only applies to vehicles with less than 19,000 km (12,000 miles) on the
odometer. Vehicles over the mileage refer to SI diagnostics.

Brand:

Model:

Model Year:
from

Buick
Cadillac
Chevrolet
GMC

VIN:
to

Engine:

from

Transmission:

to

Enclave
XT5
XT6
Blazer

M3W
2021

2024

—

—
M3V

Traverse
Acadia

Involved Region or Country

—

M3W

United States, Canada, Middle East

Overview
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 9T65 transmission replacement pilot program has
ended as of September 30, 2021, with the end of the
pilot program mandatory transmission assembly
replacement is no longer authorized per this bulletin.
Instead refer to bulletin 20-NA-138 for current guidelines for replacement of transmission assemblies.
This bulletin is being revised to convey this change and
to provide an enhanced diagnostic and repair strategy
developed through the pilot program teardown and
inspection learnings from returned transmissions.
These strategy changes will keep with the intent of the
replacement pilot program to reduce the number of
days to complete the vehicle repair and reduce the
number of repeat repair visits.
Unlike the replacement pilot program which was only
for the US dealers this diagnostic and repair strategy
can be used by all dealerships servicing vehicles with
9T65 transmissions.

Copyright 2024 General Motors. All Rights Reserved.

Page 2

May, 2024

If a customer is commenting on transmission operation
concerns on a 9T65 transmission (RPO M3W and
M3V), follow the steps below to determine repair
strategy.
Please refer to these service publications for resolutions to customer comments prior to proceeding with
this bulletin.
1. 18-NA-359 – Information on Flashing D in PRNDL
and/or Transmission Slip/Flare on 1-2 Upshift with
Zero to Very Light Throttle Input
2. 20-NA-060 – High Pitch Noise Heard When
Vehicle is Decelerating

Bulletin No.: 20-NA-136

Step Two — Fluid Level and Condition Check
Note: Ensure the transmission has enough fluid in it to
safely start the vehicle without damaging the transmission. With the vehicle off and the transmission fluid
temperature at approximately 20–25°C (68–77°F),
there must be at least enough fluid to drain out of the
fluid level hole. This will ensure that there is enough
fluid in the sump to fill the components once the vehicle
is started.
1. Start the engine.
2. Depress the brake pedal and move the shift lever
through each gear range, pausing for about 3
seconds in each range. Then move the shift lever
back to PARK (P).

3. 21-NA-201 – Information on DTC P0747 Setting at
Engine Shut Down When Transmission is in Park/
Neutral with No Hydraulic/Mechanical Transmission Concern

3. Allow the engine to idle 500–800 rpm for at least 3
minutes to allow any fluid foaming to dissipate and
the fluid level to stabilize. Release the brake pedal.

4. 21-NA-038 – Humming Noise Heard Coming From
Front End of Vehicle When Driving at Highway
Speeds

4. Keep the engine running and observe the transmission fluid temperature (TFT) using the Driver
Information Center (DIC) or a scan tool.

5. 21-NA-118 - Vibration Type Noise Heard at
Highway Speeds or with Engine Speed at
1,300-1,500 RPM

Caution: The transmission fluid level must be checked
when the transmission fluid temperature (TFT) is at 85–
95°C (185–203°F). If the TFT is not at this temperature,
operate the vehicle or allow the fluid to cool as
required. Setting the fluid level with a TFT outside this
temperature will result in either an under or over-filled
transmission. TFT 95°C under-filled, TFT 85°C overfilled. An under-filled transmission will cause premature
component wear or damage. An over-filled transmission will cause fluid to discharge out the vent tube,
fluid foaming, or pump cavitation.

6. PIP5974 - GF9 9T45/50/60/65 Transmission
1-2-3-4-5-6 Clutch Snap Ring Popout Causing
SES / DTC Code P0746 P0747
7. Torque converter shudder.
• Refer to PIP5608H – TCC Shudder Surge Fish
bite Chuggle
• Refer to latest version of 08-07-30-035 – Information on Water or Ethylene Glycol in Transmission Fluid
• Refer to Torque Converter Diagnosis in SI.

5. Raise the vehicle on a hoist. The vehicle must be
level, with the engine running and the shift lever in
the PARK range.

• If not resolved, contact Technical Assistance
(TAC). Refer to PIP5621B: GM TAC Support On
Vehicle Automatic Transmission Concerns That
Can Be Duplicated
8. In addition to the complaint, cause, and correction
notes on the repair order, this other information is
required to be noted:
• DTCs found during vehicle diagnosis – include
the DTC, what module it was in and if it was
history or current. Search all modules including
TCM, ECM, BCM, EBCM, IPC, and TRCM.
• Oil level test findings – overfill, under-fill, and
correct level. If over or under, estimate of how
much fluid.
• Oil pressure test results. Record actual pressure
reading taken.
Step One — DTCs
1. Check all Modules for DTCs. Records of all DTCs,
Current or History, and Module Located In/On
Repair Order.

5619626

6. While the vehicle is idling, remove the oil level set
plug (1). Allow any fluid to drain:

Bulletin No.: 20-NA-136

May, 2024

Page 3

• If the fluid is flowing as a steady stream, wait
until the fluid begins to drip.

− If large pieces and/or metal pieces are
noted in the fluid, record on the repair
order and it would indicate damage has
occurred internally in the transmission
and it would need to be removed from the
vehicle and investigated.

• If no fluid comes out, add fluid until fluid drips
out.
7. Record fluid level; overfilled, under-filled, correct
on repair order and how much was needed to fill or
came out:
• If fluid is overfilled, set correct level and retest.
• If fluid is under-filled, inspect for external leaks.
Refer to Fluid Leak Diagnosis.
8. If fluid level is correct, then check condition of the
fluid.

8.3.

− Fluid that is cloudy or milky or appears to
be contaminated with water indicates
engine coolant or water contamination.
Refer to the latest version of Corporate
Service Bulletin Number 08-07-30-035 for
testing and, if confirmed, find the source
of the coolant/water and repair then follow
SI document for “Engine Coolant/Water in
Transmission” for proper transmission
repair.
Inspect for external leaks. Refer to Fluid
Leak Diagnosis.
− If fluid level and condition are ok, proceed
to next step.

Step Three — Line Pressure Check
Warning:
Keep the brakes applied at all times in order to
prevent unexpected vehicle motion. Personal injury
may result if the vehicle moves unexpectedly.
Note: You may need to remove or disconnect components in order to gain access to the transmission line
pressure test hole plug.
1. Remove the line pressure test hole plug. Refer to
Automatic Transmission Fluid Pressure Test Hole
Plug Replacement in SI.
5840393

8.1.

3. Start the engine.

− The fluid should be red or dark brown.

4. Verify the Transmission Fluid Pressure = Greater
than 345 kPa (50 psi).

− It should be transparent so that objects or
writing can be seen through it. Sample #1
is an example of acceptable fluid. Sample
#2 is an example of very dark fluid.
Sample #3 is an example of black fluid.

8.2.

2. Install the GE-21867 Pressure Gauge (1).

Inspect the fluid color.

− In addition to checking the fluid color and
transparency, the fluid should be checked
for an odor of burnt fluid. If the fluid is very
dark, black, or has a burnt odor it would
indicate clutch damage has occurred
internally in the transmission and it would
need to be removed from the vehicle and
investigated.
Inspect the fluid for excessive metal particles
or other debris.
− A small amount of “friction” material is a
“normal” condition.
− A small amount of “metal” from the
manufacturing process is a “normal”
condition. This is observed as fine silver
streaks floating in the fluid.

• If pressure is below 50 psi, record on the repair
order and follow SI document for “Fluid Pressure
High of Low”.
• If above 50 psi, proceed to next step.
5. Turn the engine OFF.
6. Remove the GE-21867 Pressure Gauge.
7. Install and tighten line pressure test hole plug.
Refer to Automatic Transmission Fluid Pressure
Test Hole Plug Replacement in SI.
Step Four — Perform Road Test
Perform step 1-4 first in order to ensure the electronic
transmission components are functioning properly. If
these components are not checked, a simple electrical
condition could be misdiagnosed.
1. Connect the scan tool.
2. Ensure the gear selector is in PARK and set the
parking brake.

Page 4

May, 2024

3. Start the engine.
4. Verify that the following scan tool data can be
obtained and is functioning properly.
− Refer to Control Module References for typical
data values. Data that is questionable may
indicate a concern.
5. Check the garage shifts.
5.1.
5.2.

-

and vehicle speed. When the TCM determines that
conditions are met for a shift to occur, the TCM
commands the shift by varying current to the
appropriate PC solenoids to control oncoming and
off going clutch pressures.
6.1.

Monitor the following scan tool parameters:

⇒

Calc. Throttle Position

Apply the brake pedal and ensure the
parking brake is set.

⇒

Vehicle Speed

⇒

Engine Speed

Move the gear selector through the following
ranges:

⇒

Transmission ISS

⇒

Transmission OSS

⇒

Command Gear

⇒

TCC PC Sol. Pressure Cmd.

⇒

TCC Slip Speed

⇒

TFP Switch 1

⇒

TFP Switch 2

⇒

TFP Switch 3

⇒

TFP Switch 4

⇒

PC Sol. 2 Pressure Cmd.

⇒

PC Sol. 3 Pressure Cmd.

⇒

PC Sol. 4 Pressure Cmd.

⇒

PC Sol. 5 Pressure Cmd.

⇒

Shift Solenoid 1 and 2

⇒

PARK to REVERSE

⇒

REVERSE to NEUTRAL

⇒

NEUTRAL to DRIVE

⇒

DRIVE to REVERSE

⇒

REVERSE to DRIVE

5.3.

Pause 2 to 3 seconds in each gear position.

5.4.

Verify the gear engagements are immediate
(less than 2 seconds to complete if transmission fluid temperature is above 20°C
(68°F) and not harsh. Note that these shifts
may be almost imperceptible in some applications. Using the scan tool to monitor
Transmission ISS, achieving 0 rpm can be
used to check delay in these cases.

Note: Harsh engagement may be caused by any of the
following conditions: