File in Section:
Bulletin No.:

Service Bulletin

Date:

17-NA-376
November, 2017

INFORMATION
Subject:

Brand:

Buick

2018 Buick Regal New Model Features

Model:

Sportback
TourX
Regal GS

Model Year:
From:

2018

Region

To:

2018

From:

All

To:

All

Engine:

Transmission:

Gasoline, 4
Cylinder, L4,
2.0L, SIDI,
DOHC, VVT,
DCVCP,
Turbocharged
and Stop/Start
— RPO LTG
Gasoline, 6
Cylinder, V6,
3.6L, DI,
DOHC, VVT,
AFM and Stop/
Start —
RPO LGX

9T50 Automatic
9-Speed GEN 1
Transmission
— RPO M3D
(2.0L Turbo
Sportback
with FWD)
Aisin AF50-8
Automatic 8Speed
Transmission
— RPO MRC
(2.0L Turbo
Sportback and
TourX
with AWD)
9T60 Automatic
9-Speed, GEN
1 Transmission
— RPO M3T
(3.6L Regal GS
with AWD)

United States, Puerto Rico and U.S. Virgin Islands (Sportback, TourX and Regal GS),
Canada (Sportback and Regal GS)

Overview
Bulletin Purpose
This is a special bulletin to introduce the 2018 Regal
GS, Sportback, and TourX models. The purpose of this
bulletin is to help the Service Department Personnel
become familiar with some of the vehicle’s new
features and capabilities, the available Training
Courses and to describe some of the action they will
need to take to service these vehicles.
Trim Levels (United States)
The Sportback is available in the following trim levels:
– Regal 1SV (FWD)
– Preferred 1SB (FWD)
– Preferred II 1SC (FWD/AWD)
– Essence 1SL (FWD/AWD)
– Regal GS 1SX (AWD)

Copyright 2017 General Motors LLC. All Rights Reserved.

VIN:

Trim Levels (United States)
The TourX is available in the following trim levels:
– TourX 1SV (AWD)
– Preferred 1SB (AWD)
– Essence 1SL (AWD)
Trim Levels (Canada)
The Sportback is available in the following trim levels:
– Preferred II 1SC (FWD)
– Essence 1SL (AWD)
– Regal GS 1SX (AWD)

Page 2

November, 2017

Bulletin No.: 17-NA-376

Overview — Regal GS

4887497

Regal GS
The Regal GS is the car for commutes that are anything
but common. As Buick’s most dramatic expression of
design and dynamics, the GS is distinguished by
sportier front and rear fascias, side skirts and a rear
spoiler. This all-new model balances key characteristics
to provide customers excellent driving performance
every day and in every season. The Regal GS
advances the nameplate with a new 3.6L V-6 with 310
horsepower (231 kW) — 51 horsepower (38 kW) more
than the previous engine and 282 lb-ft (383 Nm) of
torque that features direct injection, cylinder
deactivation and advanced Stop/Start technology, a
more refined 9T60 automatic 9-speed transmission,
Intelligent AWD technology and the added functionality
and style of a five-door sportback design with seating
for up to 5 passengers. It has GS-specific,
AGR-certified, performance seats that are heated,
cooled and massaging with adjustable seat and
seat-back bolsters as well as thigh support. The sport
flat-bottom steering wheel accompanies metal
accelerator and brake pedals. The second-generation
Continuous Damping Control (CDC) suspension is
capable of 500 adjustments per second and has

Interactive Drive Control so the suspension and other
settings can be adjusted using three programmable
drive modes, which are Touring, Sport and GS. The
standard 19-inch wheels surround performance brakes
with Brembo front calipers providing confident stopping
power. A full-color head-up display is available with the
optional Driver Confidence II package. Push-button
start, remote keyless entry and 10 airbags are
standard. New to the 2018 Regal GS is the standard
Pedestrian Impact Detection System and its primary
function is to provide supplemental protection to
vulnerable road users involved in vehicle impacts. The
Regal GS offers a connected infotainment experience
with an 8-inch (203 mm) diagonal color touchscreen
infotainment system with enhanced capabilities and an
8-inch (203 mm) frameless color diagonal
reconfigurable instrument cluster as standard
equipment. Apple CarPlay™ and Android™ Auto
compatibility both come standard. Every Regal GS
comes equipped with an OnStar® 4G LTE Wi-Fi
hotspot. AT&T data plan purchase required after limited
data trial period.

Bulletin No.: 17-NA-376

November, 2017

Page 3

Overview — Sportback

4888820

Sportback
The Sportback is a five-door hatchback with a long
gracefully sloping backlight, with seating for up to 5
passengers with the ability to accommodate more
cargo and having the utility of a traditional hatchback or
wagon. The Sportback weighs around 200 pounds (91
kg) less than its predecessor, is stiffer and rides on a
longer wheelbase. With the split-folding second row
seats in place it provides 31.5 cubic feet (892 liters) of
cargo space and with the rear seats folded down it
provides 60.7 cubic feet (1,719 L) of cargo space.
– The Sportback equipped with FWD is powered by a
2.0 liter turbocharged four-cylinder engine with 250
horsepower (187 kW) and 260 lb-ft (353 Nm) of
torque with direct injection, advanced start/stop
technology and a more refined 9T50 automatic
9-speed transmission.
– The Sportback equipped with Intelligent AWD
technology is powered by a 2.0 liter turbocharged
four-cylinder engine with 250 horsepower (187 kW)
and 295 lb-ft (400 Nm) of torque with direct injection,
advanced start/stop technology and an Aisin AF50-8
automatic 8-speed transmission.

The available Driver Confidence I package adds
popular active safety features including Lane Change
Alert with Side Blind Zone Alert, Rear Cross Traffic
Alert and Rear Park Assist. A more advanced Driver
Confidence II package adds Front Pedestrian Braking,
Lane Keep Assist with Lane Departure Warning,
Forward Collision Alert and Adaptive Cruise Control
with Forward Automatic Braking.
Standard equipment on every Sportback includes
push-button start, remote keyless entry, Hill Start
Assist, 10 air bags, universal home remote and heated
side mirrors. New to the Sportback is the Pedestrian
Impact Detection System and its primary function is to
provide supplemental protection to vulnerable road
users involved in vehicle impacts. Equipped with the
standard 7-inch (178 mm) frameless diagonal color
touchscreen infotainment system, it also has an
available 8-inch (203 mm) frameless diagonal color
touchscreen infotainment system with enhanced
capabilities, both systems with Apple CarPlay™ and
Android™ Auto compatibility. An uplevel Bose® audio
system is available. Every Sportback comes equipped
with an OnStar 4G LTE Wi-Fi hotspot. AT&T data plan
purchase required after limited data trial period.

Page 4

November, 2017

Bulletin No.: 17-NA-376

Overview — TourX

4890841

TourX
The TourX is a crossover with the drive dynamics of a
car and the versatility of an SUV with seating for up to 5
passengers. The TourX rides higher than its Sportback
counterpart, enabling greater ground clearance and
capability. It has a rugged exterior appearance,
standard roof rails and interior amenities. The winged
grille is flanked by standard LED daytime running lights
and available LED headlights that are thinner and more
landscaped to enhance the low, wide appearance of
the front end. The hands-free power liftgate has a Buick
tri-shield logo lamp that illuminates the ground beneath
the sensor and is standard on upper trim levels. It is
powered by a 2.0 liter turbocharged four-cylinder
engine with 250 horsepower (187 kW) and 295 lb-ft
(400 Nm) of torque with advanced Stop/Start
technology. Power is routed to the ground via a
standard eight-speed automatic transmission and
Intelligent AWD technology with active twin clutch for
greater control on any surface. Standard equipment on
every 2018 TourX includes intelligent AWD with active
twin clutch, push-button start and remote keyless entry,
Hill Start Assist, 10 airbags, universal home remote and
heated side mirrors. New to the 2018 TourX is the
Pedestrian Impact Detection System and its primary
function is to provide supplemental protection to
vulnerable road users involved in vehicle impacts. A
7-inch (178 mm) frameless diagonal color touchscreen
infotainment system with Apple CarPlay™ and
Android™ Auto compatibility is standard on TourX and
Preferred trims, while an 8-inch (203 mm) frameless

diagonal color touchscreen infotainment system with
enhanced capabilities is standard on the Essence trim
with available embedded navigation optional. Bose®
premium audio with an innovative subwoofer mounted
in the spare tire well is also standard with active noise
cancellation. Every TourX also comes equipped with an
OnStar 4G LTE Wi-Fi hotspot. AT&T data plan
purchase required after limited data trial period.
TourX Storage

4894966

Bulletin No.: 17-NA-376

November, 2017

TourX has a functional 73.5 cu.ft (2,081 liters) of cargo
area with the rear seat folded down.

•

Brakes
These vehicles are equipped with a Bosch ABS 9.0
brake system and low-drag four-wheel disc brakes. The
electronic brake control module (EBCM) and the brake
pressure modulator valve are serviced separately. The
brake pressure modulator valve uses a four circuit
configuration to control hydraulic pressure to each
wheel independently. Vehicles built with option RPO
FX3 will feature stability enhancement.
Depending on the vehicle options, the following
performance enhancement systems are provided:
• Antilock Brake System: When wheel slip is
detected during a brake application, an Antilock
Brake System (ABS) event occurs. During ABS
braking, hydraulic pressure in the individual wheel
circuits is controlled to prevent any wheel from
slipping. A separate hydraulic line and specific
solenoid valves are provided for each wheel. The
ABS can decrease, hold, or increase hydraulic
pressure to each wheel. The ABS does not,
however, increase hydraulic pressure above the
amount which is transmitted by the master
cylinder during braking.
• Pressure Hold: The EBCM closes the inlet valve
and keeps the outlet valve closed in order to
isolate the system when wheel slip occurs. This
holds the pressure steady on the brake so that the
hydraulic pressure does not increase or decrease.
• Pressure Decrease: The EBCM decreases the
pressure to individual wheels during a
deceleration when wheel slip occurs. The inlet
valve is closed and the outlet valve is opened. The
excess fluid is stored in the accumulator until the
return pump can return the fluid to the master
cylinder. The EBCM decreases the pressure to
individual wheels during a deceleration when
wheel slip occurs. The inlet valve is closed and the
outlet valve is opened. The excess fluid is stored
in the accumulator until the return pump can return
the fluid to the master cylinder.
• Pressure Increase: The EBCM increases the
pressure to individual wheels during a
deceleration in order to reduce the speed of the
wheel. The inlet valve is opened and the outlet
valve is closed. The increased pressure is
delivered from the master cylinder.
• Brake Assist: The Brake Assist function is
designed to support the driver in emergency
braking situations. The EBCM receives inputs
from the brake pressure sensor. When the EBCM
senses an emergency braking situation, it will
actively increase the brake pressure to a specific
maximum.

•

•

•

Page 5

Electronic Brake Distribution: The electronic
brake distribution function is designed to support
the driver in emergency braking situations. The
electronic brake distribution is a control system
that enhances the hydraulic proportioning function
of the mechanical proportioning valve in the base
brake system. The electronic brake distribution
control system is part of the operation software in
the EBCM. The electronic brake distribution uses
active control with existing ABS in order to
regulate the vehicle's rear brake pressure.
Electronic Stability Control — RPO FX3: The
Electronic Stability Control (ESC) adds an
additional level of vehicle control to the EBCM.
Yaw rate is the rate of rotation about the vehicles
vertical axis. The electronic stability control is
activated when the EBCM determines that the
desired yaw rate does not match the actual yaw
rate as measured by the yaw rate sensor. The
difference between the desired yaw rate and the
actual yaw rate is the yaw rate error, which is a
measurement of over steer or under steer. If the
yaw error becomes too large, the EBCM attempts
to correct the vehicles yaw rate motion by applying
differential braking to the appropriate wheel. The
amount of differential braking applied to the left or
right front wheel is based on both the yaw rate
error and side slip rate error.
Hill Start Assist: When stopped on a hill, the Hill
Start Assist (HSA) feature prevents the vehicle
from rolling before driving off, whether facing uphill
or downhill by holding the brake pressure during
the transition between when the driver releases
the brake pedal and starts to accelerate. The
EBCM calculates the brake pressure, which is
needed to hold the vehicle on an incline or grade
greater than 5% and locks that pressure for up to
two seconds by commanding the appropriate
solenoid valves ON and OFF when the brake
pedal is released. The stop lamps will stay
illuminated during the HSA operation even though
the brake pedal is released. This is considered
normal operation.
Traction Control: When drive wheel slip is noted,
the EBCM will enter traction control mode. First,
the EBCM requests the engine control module
(ECM) to reduce the amount of torque to the drive
wheels via a serial data message. The ECM
reduces torque to the drive wheels and reports the
amount of delivered torque. The ECM reduces
torque to the drive wheels by retarding spark
timing and turning OFF fuel injectors.

Page 6

November, 2017

Engine 2.0L L4 Turbocharged —
RPO LTG

•

4423531

2.0L Turbocharged Engine
Overview
Performance from GM’s Ecotec family of engines
continues to advance with the 2.0L Turbocharged —
RPO LTG, which is based on a generation of large
displacement four cylinder engines which are designed
for greater efficiency. The turbocharger generates up to
20 pounds (138 kPa) of boost and its twin-scroll design
helps optimize the usable power from the engine,
virtually eliminating turbo lag and helping deliver a
broad power band. It also gives the engine the rapid
throttle responsiveness associated with a higher
displacement naturally aspirated high performance
engine. Electronically controlled turbocharger
supporting components including the wastegate and
bypass valve, help optimize performance and
efficiency.

•

Engine Component Description and Operation
•

•

Cam-Driven High Pressure Fuel Pump: A high
pressure, cam-driven fuel pump provides the
higher fuel pressure required by the direct
injection system. The engine mounted fuel pump
is augmented by a conventional electrically
operated supply pump in the fuel tank. The fuel
delivery system features a high-pressure stainless
steel feed line and a pressure regulated fuel rail
without a conventional fuel return line from the
engine to the tank. Fuel pressure varies from
about 750 psi (5,171 kPa) at idle to 2,250 psi
(15,513 kPa) at wide open throttle (WOT).
Cylinder Block: The sand-cast aluminum 319T7
cylinder block is a superior refinement of previous
Ecotec engine block castings. It is dimensionally
similar with previous Ecotec turbo block variants,

•

Bulletin No.: 17-NA-376

while providing improved structural support, as
well as enabling greater control of noise, vibration
and harshness. The main bearing bulkheads,
which support the crank bearings, as well as the
cylinder bore walls have been significantly
strengthened to support increased engine loads.
Refinements to the oil distribution system enable
improved oil flow throughout the engine and an
expansion of the coolant jacket, along with the use
of cast-in-place bore liners, allows more precise
bore roundness and improves the block’s ability to
dissipate heat.
Cylinder Head — Rotocast Aluminum with
Sodium Filled Exhaust Valves: The Ecotec 2.0L
turbo's A356T6 aluminum cylinder head is cast
using a Rotocast process for high strength,
reduced machining and improved port flow. The
head is also designed specifically for direct
injection. The 2.0L turbo head has unique injector
mounting locations below the ports. Apart from
injector installation, the head has conventional
port and combustion chamber designs, both are
optimized for direct injection and high boost
pressure. The head uses stainless steel intake
valves that are nitrided for improved durability and
undercut to improve flow and reduce weight. The
exhaust valves have sodium-filled stems that
promote valve cooling. At normal engine operating
temperatures, the sodium inside the valve stem
fuses and becomes liquid. The liquid sodium
improves conductivity, promoting heat transfer
away from the valve face and valve guide to the
cooler end of the stem, where it more readily
dissipates. This helps maintain a lower, more
uniform valve temperature, reducing wear on the
valve guide for better alignment and a consistent
seal between the valve seat and valve face over
the life of the engine. The exhaust manifold is
mounted to the cylinder head and is made of cast
stainless steel. It is extremely durable and delivers
exceptional airflow qualities.
DOHC with Continuously Variable Valve
Timing: Overhead cams are the most direct,
efficient means of operating the valves, while four
valves per cylinder increase airflow in and out of
the engine. This arrangement is integrated on the
lightweight aluminum cylinder head. Continuously
variable valve timing optimizes the engine's
turbocharging system by adjusting valve timing at
lower rpm for improved turbo response and
greater torque delivery. Both the intake and
exhaust cams have hydraulically operated