Transmission
Overview
The 2020 Buick Encore GX offers two automatic
transmissions including Hydra-Matic 9T45 (M3F), and
the VT40 (MRG). The 9T45 transmission is a
GM-developed 9-speed automatic transmission.
5501203

1. 3-8 Clutch Assembly
2. 5-7-R Clutch Assembly
3. 6-7-8-9 Clutch Assembly
4. 4th Clutch Assembly
5. 2-9 Clutch Assembly
6. 1-2-3-4-5-6 Clutch Assembly
Clutches
The friction components used in this transmission
consist of six multiple disc clutches. The multiple disc
clutches combine with one selectable one way clutch to
deliver ten different gear ratios—nine forward and one
reverse.

5501202

Page 14

February, 2020

Bulletin No.: 20-NA-032

The TCM receives and monitors various electronic
sensor inputs and communicates with other modules,
including the ECM. This information is used to shift the
transmission at the optimum time.

5501204

Accumulator
The automatic transmission auxiliary fluid accumulator
supplies transmission fluid line pressure to the
appropriate clutches for an auto start event. Attached to
the accumulator is a normally closed ON / OFF
solenoid. When the ignition is ON, the TCM supplies
12V to the accumulator solenoid. To complete the
circuit, the TCM supplies a control circuit to the
accumulator solenoid. When the Engine Control
Module (ECM) requests an auto start event, a serial
data message is sent to the TCM to command the
solenoid ON. This allows captured pressurized fluid to
exit the accumulator to apply the clutches for a first
gear start.

5501205

Transmission Control Module
The TCM for the 9T45 is a standalone unit mounted to
the front of the transmission.

5501207

Manual Mode
Manual mode, also referred to as electronic range
select mode, allows the driver to choose the top gear
limit of the transmission, and the vehicle's speed. This
is particularly useful while driving downhill or towing a
trailer. Moving the gear selector from the Drive (D)
position to the Low (L) position places the transmission
in manual mode. Pressing the “+” or “-” increases or
decreases the top gear limit of the transmission.
Transmission Adaptive Functions
The 9T45 9-speed transmission uses a line pressure
control system during upshifts to compensate for new
transmission build variation and the normal wear of
transmission components. New
transmission-to-transmission variation and normal wear
of the apply components can, over time, cause shift
time to be longer or shorter than desired. In order to
compensate for these changes, the TCM adjusts the
pressure commands to the various control 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
and increased transmission durability. The TCM
monitors the Input Shaft Speed sensor (ISS) sensor,
and the Output Shaft Speed sensor (OSS) Sensor
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.

Bulletin No.: 20-NA-032

February, 2020

Page 15

grades. With LOW range selected, the variable drive
and driven pulleys will not be allowed to achieve high
ratios.

5501208

Hydra-Matic VT40 (MRG) Automatic Transmission
The VT40 is a fully automatic single mode continuously
variable, front-wheel drive transmission. The
transmission consists primarily of:
– a four-element torque converter
– one planetary gear set
– an electronic hydraulic pressurization and control
system
– a variable drive and driven pulley assembly
– variable drive chain
– two friction clutches
– a differential assembly
The transmission can be operated in any one of the five
different positions shown on the shift quadrant.
– Park (P) — The Park position enables the engine to
be started while preventing the vehicle from rolling
either forward or backward. For safety reasons, the
vehicle parking brake should be used in addition to
the transmission "PARK" position.
– Reverse (R) — The REVERSE position enables the
vehicle to be operated in a rearward direction.
– Neutral (N) — The NEUTRAL position enables the
engine to start and operate without driving the
vehicle.
– Drive (D) — DRIVE range should be used for all
normal driving conditions for maximum efficiency
and fuel economy. DRIVE range allows the
transmission to operate in the full range of variable
ratios. The DRIVE position allows low to high ratios
without any limitations and torque converter clutch
apply.
– Low (L) — This position can be selected at any
vehicle speed. If the transmission is in DRIVE, it will
immediately change the ratio to low when vehicle
speed is below approximately 56 km/h (35 MPH).
This is particularly beneficial for maintaining
maximum engine braking when descending steep

5501210

Torque Converter
The four-element torque converter contains a pump, a
turbine, a pressure plate splined to the turbine, and a
stator assembly. The torque converter acts as a fluid
coupling to transmit power smoothly from the engine to
the transmission. It also hydraulically provides
additional torque multiplication when required. The
pressure plate, when applied, provides a mechanical
"direct drive" coupling of the engine to the transmission.
Automatic Transmission Fluid Pump and Auxiliary
Fluid Pump
The transmission fluid pump is a binary vane type,
which effectively allows for two pumps in the packaging
size of one. This design and packaging strategy not
only enables low parasitic losses and optimum priming
capability, but also provides for ideal oil routing to the
controls system, with the pump located in the valve
body itself.

Safety and Security
Overview
A strong vehicle structure, combined with several
advanced safety features, ensures that the 2020 Buick
Encore GX provides a safe driving experience.
Occupant protection features include Supplemental
Inflatable Restraint (SIR) system airbags, dual-mode
seatbelts, and seatbelt pretensioners. To help secure
child safety seats, the Encore GX is equipped with both
the international standard for child restraint seats
(ISOFIX), lower anchors, and top tether features.
Available driver awareness and driver assistance
packages also offer additional advanced safety
technology such as lane departure warnings, blind
zone alerts, collision alerts, and rear cross traffic alert,
rear vision camera, and pedestrian impact detection.

Page 16

February, 2020

Bulletin No.: 20-NA-032

and include up to 10 frontal and side impact air bags,
as well as the SDM, seat belt pretensioners (anchor
and retractor), and impact sensors.
Inflatable Restraint Sensing and Diagnostic Module
The SDM is the control center for the SIR system and
contains both internal sensors as well as external
impact sensors. In the event of a collision, the SDM
compares the signals from these sensors to a value
stored in its memory. When the generated signals
exceed the stored value, the SDM will cause current to
flow through the appropriate deployment loops in order
to deploy the air bags.

5501193

Seat Belts
The front seat of the Encore GX features three-point lap
and shoulder seat belts with height adjustable upper
anchors for maximum comfort. The front seat belt
pretensioners remove the slack in the event of a
collision.
In the rear of the vehicle, each outer position and the
center position feature a three-point seat belt, which are
not height adjustable.
All front and rear passenger seat belt retractors
incorporate an automatic locking feature for child seat
installation.

Supplemental Inflatable Restraint Impact Sensors
The SIR system contains either five or six impact
sensors, depending on the market. The impact sensors
are inputs to the SDM. The sensors for the SIR system
are in the following locations:
– front center of engine compartment or on the radiator
support on the left and right sides
– inside the front doors (right and left)
– under the trim panel at the base of the C pillars (right
and left)
Dual-Stage Frontal Air Bags
The two-stage steering wheel and passenger
instrument panel air bags vary the amount of restraint
to the occupant according to the collision severity and
passenger seat position. For moderate frontal
collisions, the air bags partially deploy (stage 1 of air
bag deployment). For more severe frontal collisions,
the air bags fully deploy (stage 2 of air bag
deployment).
Driver and Passenger Roof Rail Air Bags
Roof rail side-curtain air bags provide head and neck
protection to front and rear seat occupants, in the event
of a side impact or vehicle rollover. The air bags are
located along the roofline, above the doors.

5501194

Supplemental Inflatable Restraint (SIR) System
Solid vehicle structure, coupled with SIR system
components, helps maximize protection for vehicle
occupants in the event of a collision. The SIR system
supplements the protection offered by the seat belts

5501195

Bulletin No.: 20-NA-032

February, 2020

Page 17

Passenger Presence Detection System and
Passenger Air Bag Indicator
The passenger presence detection system detects the
presence of a front passenger seat occupant. The
passenger presence system consists of a passenger
presence module, silicone filled sensor pad, passenger
seat belt tension sensor, wiring harness, and
passenger air bag on/off indicators.

5501199

5501198

Rear Cross Traffic Alert
The rear cross traffic alert uses radar sensors to warn
the driver of approaching cross traffic when backing out
of a parking spot. This system uses the same side
radar sensors that are used for the side blind zone
alert. The system helps give drivers more time to react
to obstacles that may be difficult to see in the side
mirror.

Automatic Parking Assist with Braking
Automatic parking assist with braking is an optional
feature on the Buick Encore GX that allows the vehicle
to search for and steer the vehicle into parallel and
perpendicular parking spots. This system adds four
side sensors: two in the sides of the front fascia and
two in the sides of the rear fascia.
Pedestrian Collision Mitigation Braking
Pedestrian collision mitigation braking is a subsystem
feature of the forward automatic braking system. This
goal of this feature is to reduce the likelihood of
collisions or the impact speed with pedestrians while
traveling in the forward direction.

5501200

Side Blind Zone
The side blind zone alert system detects and reports
vehicles or other moving objects of interest on either
side of the vehicle. The system is designed to alert the
driver, with a visual display placed on the side view
mirror, to the presence of objects of interest that may
not be visible in the inside rear view mirror and outside
rearview mirrors. The outside rear view mirrors contain
an icon that is backlit with high intensity, amber-colored
LEDs located on the mirror surface. The display
brightness adapts to day / night conditions.

Page 18

February, 2020

Bulletin No.: 20-NA-032

Suspension
Overview
The Buick Encore GX features robust front and rear
frames, a MacPherson strut front suspension, and a
semi-independent twist-beam rear suspension.
The due to a variety of chassis components On
All-Wheel Drive (AWD) models, traction select is a
switchable feature that enables the driver to switch
between drivelines to optimize fuel economy under
varying driving conditions to improve traction.

5501201

Lane Departure Warning / Lane Keep Assist
The lane departure warning system is a camera-based
lane detection system that warns the driver of
un-signaled lane changes. The system uses the front
view camera, identifies traffic lane markings, and
provides audible alerts if the vehicle begins to drift out
of the lane without the turn signal activated.
The lane departure warning system operates at speeds
of 60 km/h (37 MPH) or greater.
Front View Camera Module
The front view camera is located behind the windshield,
near the rear view mirror. Looking out at the road
ahead, it detects visual cues, such as lane markings
and vehicles directly ahead, within a distance of
approximately 60 m (197 ft.). The frontview camera
communicates with the instrument cluster via serial
data to illuminate the appropriate amber or green
vehicle ahead indicator, collision alert indicators. The
frontview camera also communicates via serial data
with the infotainment system to request audible alerts.
Forward Collision Alert
The forward collision alert system sends a warning to
the driver when there is a potential collision risk. The
system uses the forward view camera to detect
vehicles directly ahead. When equipped with adaptive
cruise control, the forward collision alert uses the front
long-range radar module and two front short- range
radar modules in addition to the forward view camera.
Parking Assist System
Front and rear parking assist system identifies and
notifies the driver of an object in the vehicle’s path
when moving in a forward or reverse direction at
speeds less than 8 km/h / (5 MPH). Eight sensors
determine the distance and location of the object: four
in the rear bumper and four in the front bumper. The
parking assist system notifies the driver of an object in
the vehicle’s path using an audible beep signal through
the infotainment system.

5501190

Front Suspension
The front suspension uses strut assemblies to support
vehicle weight and dampen suspension oscillations.
The lower part of each front aluminum steering knuckle
connects to the control arm assembly with a ball joint.
The upper part of each steering knuckle attaches to the
shock absorber and strut assembly, which attaches to
the body structure.
Front Camber Adjustment
Adjusting the front camber may be necessary if the
wheel alignment is out of specification. This is
accomplished place a service bolt in place of the upper
strut to steering knuckle bolt. The new bolt is 2 mm
smaller in diameter to allow for adjustment. Do not file
the strut holes to attempt to make an adjustment.

Bulletin No.: 20-NA-032

February, 2020

Page 19

Steering
Overview

5501191

Semi-Independent Twist Beam Rear Suspension
The rear suspension features a semi-independent
twist-beam axle with coil springs, shock absorbers, and
integral trailing arms. The twist-beam offers such
advantages as minimum space requirements, low
weight, and consistent camber control. The beam’s
twisting characteristics provide exceptional driving
stability, as well as agile, on-center steering. Rear
suspension angles are non-adjustable.
Watt’s Link Stabilizer
The all-wheel drive vehicles are equipped with a rear
stabilizer system called a Watt’s link.
The rear suspension uses a Watt’s linkage as a
performance enhancement. Watt’s linkage prevents
relative sideways motion between the axle and body of
the vehicle. Watt’s linkage approximates a vertical
straight-line motion more closely and does so while
locating the center of the axle.
Tire Pressure Monitoring System with Tire Fill Alert
The tire pressure monitoring system warns the driver
when a significant loss or gain of tire pressure occurs in
any of the four tires. The driver can choose to display
individual tire pressures and their locations on the
driver information center. The tire pressure monitoring
system also features a tire fill alert. The standard tire fill
alerts the driver if tire pressure any of the four tires
drops to 25 percent or more below the recommended
cold inflation pressure by activating a warning indicator.

5501123

The 2020 Buick Encore GX features an electric power
steering system. This system reduces driver steering
effort and increases driver comfort, especially during
low speed maneuvers. The steering gear converts
steering wheel rotation into side-to-side movements.
Tie rods transfer this force to the steering knuckles and
front wheels, which turn the vehicle right or left based
on driver inputs.
Electric Power Steering System
The electric power steering system reduces the amount
of effort needed to steer the vehicle by using the power
steering control module to control the 12 volt power
steering motor that maneuvers the steering gear. The
power steering control module uses input from the
torque sensor, motor rotational sensor, battery voltage
circuit, and General Motors Local Area Network
(GMLAN) serial data circuit to determine the level of
motor assist. Vehicle speed and engine run status are
also used to adjust the amount of steering assist
needed. At low speeds, more assist is provided for
easy turning during parking maneuvers. At higher
speeds, less assist is provided for improved road feel
and directional stability.

Page 20

February, 2020

Bulletin No.: 20-NA-032

5501122

Steering Wheel and Column
The steering wheel features a three-spoke design with
a thick rim section for enhanced grip and feel. The
steering wheel also has a strategically placed raised
areas at the 10 o’clock and 2 o’clock positions that
provide comfort in those hand positions. On the
steering wheel itself, there are controls for the driver
information center, infotainment system and, and cruise
control.
Heated Steering Wheel
The heated steering wheel system consists of a
steering wheel containing a heating element, a heated
steering wheel switch, and a steering wheel heating
module. The heated steering wheel includes a
non-serviceable heating element and temperature
sensor located in the rim of the steering wheel. The
heated steering wheel on/off switch is located on the
left side of the steering wheel. The steering wheel heat
module is located on the front side of the steering wheel
center hub.

Training Courses
Training Courses — Description and Number
Description

Course Name and Number

The 2020 Buick Encore GX Introduction course introduces you
to the newest addition to Buick’s SUV portfolio, sharing key
features and benefits of the 2020 Buick Encore GX and
highlighting the competitive landscape.

B40EC.L20W1 2020 Buick Encore GX Introduction (U.S.)

This New Model Features course provides an awareness of
the unique and new technology related to the 2020 Buick
Encore GX.

10320.13W 2020 Buick Encore GX New Model Features

Bulletin No.: 20-NA-032

February, 2020

Page 21

Version Information
Version

1

Modified

Released February 10, 2020

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.

WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION