pressure commands to the various pressure control
(PC) solenoids to maintain the originally calibrated shift
timing. The automatic adjusting process is referred to
as “adaptive learning” and it is used to ensure
consistent shift feel plus increase transmission
durability.
The TCM monitors the A/T input speed sensor (ISS)
and the A/T output speed sensor (OSS) during
commanded shifts to determine if a shift is occurring
too fast (harsh) or too slow (soft) and adjusts the
corresponding PC solenoid signal to maintain the set
shift feel. The purpose of the adapt function is to
automatically compensate the shift quality for the
various vehicle shift control systems. The adapt
function is a continuous process that will help to
maintain optimal shift quality throughout the life of the
vehicle.

How to Adapt Your Transmission
Transmission adapts can be reset and relearned on
most vehicles through GDS2 by using the Transmission
Service Fast Learn procedure. This procedure is
completed in the service stall and no vehicle driving is
required.
To complete the Transmission Service Fast Learn
procedure, enter GDS2 Diagnosis and navigate to:
• Module diagnostics
• Transmission Control Module
• Configuration / Reset Function
• Transmission Service Fast Learn
Transmission Service Fast Learn is the recommended
method to reset and relearn adapts. This procedure is
available on all 2015-2021 MY Trucks, Cars and SUVs
with 8L45 and 8L90 Automatic Transmissions (RPOs:
M5U, M5T, M5N, M5X, MQD, MQE).
When the Service Fast Learn is complete, perform a
test drive and note any soft or harsh shifts.
To improve these complaint shifts further, locate the
clutches that need to be learned in the table below, and
perform the required learning procedure for each clutch
listed in the table. Execute the steps below with the
vehicle warmed up on a smooth level road. The driver
may observe a brief pulse behavior or firm shift feel
while the transmission is optimizing the clutch learn
characteristics.

Bulletin No.: 16-NA-019

April, 2023

Note: The transmission fluid temperature must be
between 35°C (95°F) and 95°C (203°F). Drive the
vehicle under normal conditions until this temperature
range is achieved. If the temperature is outside of this
range, the clutches will not be learned.
To Correct The
Shift Feel

Learn These Clutches
Applying
Clutch

Releasing
Clutch

1–2

C4

C3

2–3

C3

C1

3–4

C5

C3

4–5

C3

C4

5–6

C4

C2

6–7

C1

C4

7–8

C4

C3

3–1

C1

C4

C3

C4

2–1
N-D

C3 – Perform garage shift adaptive
learning

N-R

C5 – Perform garage shift adaptive
learning

Power Downshifts

Just perform the shifts and they will
adapt

Note: Ensure Service Bulletin #16-NA-411 or
#16-NA-412 has been completed on the 2015 -2016
Silverado, Sierra, Yukon and Escalade models before
performing this procedure.
Note: For the 2015 Corvette, use the latest version of
Service Bulletin #14-07-30-001.
Note: The following adaptive learning procedure
was developed to further learn clutch pressures
and volumes required for specific shifts. To
expedite the learning process, it is recommended
to utilize a road with minimal traffic volume that has
as smooth and level surface as possible.
Note: Within GDS2, a Transmission Service Fast
Learn Data page has been created to aid in performing
adaptive learn by showing throttle percentage, engine
speed, transmission fluid temperature, and gear
command.
Note: 2018-2022 Model Year vehicles show the clutch
learn status within GDS2. A Transmission Service Fast
Learn Data page has been created to aid in performing
adaptive learn by showing throttle percentage, engine
speed, transmission fluid temperature, and gear
command.

Page 3

To Learn C1 (For 6-7 or 3-1 Shift)
1. Pressure Learns:
Note: It is recommended to utilize a road with a speed
limit between of 48-72 km/h (30-45 mph) for this
procedure.
• Shift the transmission into 6th gear with the
PRNDM in the M position. Obtain an engine
speed between 1000 and 1600 engine rpm.
Maintain this condition for a total of about 8 km
(5 mi). Cruise control may be used and has
been found to result in faster learning of the
clutch values.
2. Volume Learns:
• Complete 15 light throttle 6-7 upshifts at
approximately 15% throttle to further learn C1.

To Learn C2 (For 6-5 Shift)
1. Pressure Learns:
Note: It is recommended to utilize a road with a speed
limit 64-72 km/h (40-45 mph) for this procedure.
• Perform 10 normal mode 6-5 coast down shifts
(zero/light brake) to learn the C2 Return Spring
pressure.
2. Volume Learns:
• Shift the transmission into 8th gear with the
PRNDM in the M position. Obtain an engine
speed between 1000 and 1750 rpm. Maintain
this condition for a total of about 8 km (5 mi).
Cruise control may be used and has been found
to result in faster learning of the clutch values.

To Learn C3 (For 2-3, 4-5, or N-D Shift)
Important: Application Specific Silverado & Sierra
e-Assist (RPO M5X) Trucks: To enable Adaptive
Learn on 8-7 Coast downs, a power on (~15% throttle
through the upshift) 7-8 upshift must be performed prior
to each downshift. This action enables torque converter
clutch (TCC) controlled slip on downshift to occur vs.
TCC unlocked, which occurs on normal downshifts and
disables Adaptive Learn. As a supplement, if the
previous procedure is unsuccessful using GDS TCC
Control Functions, TCC can be left enabled during 8-7
Coast downs to aid in learning C3 pressure.
1. Pressure Learns:
• Perform 10 normal mode 8-7 coast down shifts
(zero/light brake) to learn the C3 Return Spring.
2. Volume Learns:
• Complete 15 light throttle 2-3 upshifts at
approximately 15% throttle to further learn C3.

Page 4

April, 2023

To Learn C4 (For 1-2, 5-6, or 7-8 Shift)
1. Pressure Learns:
Note: It is recommended to utilize a road with a speed
limit between of 64-72 km/h (40-45 mph) for this
procedure.
• Shift the transmission into 7th gear with the
PRNDM in the M position. Obtain an engine
speed between 1000 and 1750 rpm. Maintain
this condition for a total of about 8 km (5 mi).
Cruise control may be used and has been found
to result in faster learning of the clutch values.
Important: Application Specific Express & Savana
Vans Pressure Learns: Perform 10 normal mode 7-6
coast down shifts (zero/light brake) to learn the C4
Return Spring.
2. Volume Learns:
• Complete 15 light throttle 1-2 upshifts at
approximately 15% throttle to further learn C4.

To Learn C5 (For 3-4 or N-R Shift)
1. Pressure Learns:
Note: It is recommended to utilize a road within a
Business Park or similar area, where it is safe to drive
at very slow speeds of approximately 8-40 km/h
(5-25 mph).
• Shift the transmission into 3rd gear with the
PRNDM in the M position. Start a very slow
acceleration, starting at about 1000 rpm.
Maintain the slow acceleration until you reach
about 2500 rpm. Once you reach 2500 rpm,
slow back down to 1000 rpm and repeat the
slow acceleration up to 2500 rpm. Repeat this
10 times.

Bulletin No.: 16-NA-019

2. Volume Learns:
• Complete 15 light throttle 3-4 upshifts at
approximately 15% throttle to further learn C5.

Power Downshift Adaptive Learning
Starting with the vehicle operation in 8th gear, slowly
apply pressure to the accelerator pedal until downshift
occurs. Repeat as necessary in each gear (8, 7, 6, 5, 4,
3 and 2).
Note: This procedure will learn the off-going clutch
adapts for desired power downshift control.

Garage Shift Adaptive Learning (For N-D or N-R
Shift)
1. After above clutches are learned C3 –Drive and C5
– Reverse. With the vehicle at a stop, hold foot on
brake pedal and move the shifter from Neutral to
Drive and release the brake once in gear allowing
the vehicle to roll 5-10 feet or Neutral to Reverse
and release the brake once in gear allowing the
vehicle to roll 5-10 feet. Repeat as necessary until
desired shift quality is achieved.
Note: This procedure will learn the C13567 (C3-Drive)
and C45678R (C5 – Reverse) oncoming clutch adapts.

Warranty Information
For vehicles repaired under the Powertrain coverage,
use the following Labor Operation. Reference the
Applicable Warranties section of Investigate Vehicle
History (IVH) for coverage information.
Labor
Operation
8480318*

Description

Labor Time

Transmission Service Fast
Learn

Use Actual
Clock Time

*This is a unique Labor Operation for bulletin use only.
Version

10

Modified

Released January 25, 2016
Revised August 19, 2016 – Added the 2017 Model Year and updated information.
Revised November 13, 2019 – Added the 2018 Model Year and a Warranty statement.
Revised September 02, 2020 – Removed Buick from Models table, added the 2015 and
2019-2021 Model Years, added RPO MQE, updated the Involved Region or Country
section, updated the two bullet items under Correction, added a Note to the Condition
and Correction sections and updated the Notes just below the Shift/Clutch table.
Revised November 16, 2020 – Added RPO MQD and updated Description of Labor
Operation.
Revised December 01, 2020 – Changed Labor Operation Description back to previous
Description.
Revised July 20, 2021 – Changed Models from GM Passenger Cars and Trucks to
specific Models and Years.
Revised May 06, 2022 – Added the 2022 Model Year to applicable vehicles and updated
the Involved Region or Country section.
Revised March 21, 2023 – Added the 2023 Model Year to applicable vehicles.
Revised April 14, 2023 – Removed TIS information from 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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