Bulletin No.:

Service Bulletin

Date:

18-NA-366
November, 2019

INFORMATION
Subject:

2019 Chevrolet Silverado 4500HD 5500HD and 6500HD New Model Features

Brand:

Model:

Chevrolet

Silverado
4500HD
Chassis-Cab
Silverado
5500HD
Chassis-Cab
Silverado
6500HD
Chassis-Cab

Model Year:
From:

Involved Country

Copyright 2019 General Motors LLC. All Rights Reserved.

To:

2019

United States

VIN:
From:

To:

—

Engine:

Transmission:

Duramax® 6.6L
V8 Diesel —
RPO L5D

Allison®
6-Speed
Automatic
(RPO Will Vary
by Vehicle and
Application)

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November, 2019

Bulletin No.: 18-NA-366

Overview

5122202

2019 Silverado 4500HD — Preproduction Model
Shown

Bulletin No.: 18-NA-366

November, 2019

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5136828

2019 Silverado 6500HD — Preproduction Upfitted
Model Shown
Bulletin Purpose
This purpose of this bulletin is to introduce the new
2019 Chevrolet Silverado 4500HD, 5500HD and
6500HD medium duty trucks. The bulletin will help the
Service Department Personnel become familiar with
the vehicle’s new Duramax® 6.6L V8 — RPO L5D
diesel engine, the Allison® transmission with an
available PTO option, brake system, chassis, and other
general information. These trucks are available
exclusively as chassis cab models, making them ready
for up-fitters to customize for the various requirements
of their customers. The trucks will be available in 2WD
and 4WD. They will be very connected, with options
that include OnStar®, Commercial Link, a built-in
OnStar® 4G LTE™ Wi-Fi® Hotspot (requires a paid
data plan), as well as wireless cell phone charging and
Bluetooth®. They also support the Apple® CarPlay™
software feature and Android™ Auto™ application.
They will be built in partnership with Navistar at its
Springfield, Ohio plant.

Additional highlights include:

5137314

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Preproduction image shown.
Clean top of rail design with no protruding welds or
brackets for smooth integrated upfits.
Robust, single-piece frame rail for enhanced
durability.
Factory-available rear air suspension.
Fuel tank capacity of up to 65 gallons (246 liters).

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November, 2019

Bulletin No.: 18-NA-366

Painted chassis provides corrosion protection.
40/20/40 split-bench front seat
60/40 rear bench seat (Crew Cab)
Standard Grille Guard Screen for insect protection
is mounted behind the grille.

5156383

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Preproduction model shown.
Dual batteries with protective cover in place.

5134340

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Preproduction model shown.
Tilt engine cover design. Provides service
technicians with easy and comfortable access to
the engine.

5124232

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5181883

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Preproduction model shown.
The dual batteries are located under the cab on
the driver side of the vehicle. An auxiliary
jump-start 12V positive stud with a protective
cover is located on the driver side of the vehicle
beneath the driver door and to the left of the
batteries.

Preproduction model shown.
Up to 50-degree wheel cut enhances turning
radius and maneuverability and also allows for
easier serviceability.

Bulletin No.: 18-NA-366

November, 2019

Page 5

5175908

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Preproduction model shown.
Easy-to-reach control buttons. Available upfitter
switches, (4) provide 4-30 amp circuits to facilitate
installation of aftermarket electrical accessories
and are located on the instrument panel.

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Some vehicles may be equipped with a
110/120-Volt Alternating Current power outlet. It
can be used to plug in electrical equipment that
uses a maximum of 150 watts. If equipped with a
center console, the power outlet is in front of the
cupholders. If equipped with bench seats, the
power outlet is on the center stack.

5170757

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If equipped, the sunglasses storage compartment
is in the overhead console. Press the button on
the cover and release to access.

5182463

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November, 2019

The Oil Life Monitor calculates engine oil life
based on vehicle use parameters and displays the
percentage of Oil Life Remaining and Change
Engine Oil Soon on the DIC when it’s necessary to
change the engine oil and filter. The Oil Life
Monitor should be reset to 100% only following an
oil and filter change.

Available Models and Trim Level
The following Regular Cab and Crew Cab Models and
Trim Levels are available:
– Crew Cab: 2WD 1WT
– Crew Cab: 2WD 1LT
– Crew Cab: 4WD 1WT
– Crew Cab: 4WD 1LT
– Regular Cab: 2WD 1WT
– Regular Cab: 2WD 1LT
– Regular Cab: 4WD 1WT
– Regular Cab: 4WD 1LT
Wheelbase — Overall Length — Cab to Axle

5136912

The following are available:
– Regular Cab: Wheelbase: 141—243 inches (7)
– Regular Cab: Length: 224.5—360 inches (12)
– Regular Cab: Cab to Axle: 60, 84, 108, 120, 138,
150, 162 inches
– Crew Cab: Wheelbase: 175, 199, 235 inches
– Crew Cab: Length: 258.8, 282.8, 296.6, 344.2
inches
– Crew Cab: Cab to Axle: 60, 84, 120 inches

Brakes
Bosch TCS8TA Brake System
This vehicle is equipped with a Bosch TCS8TA brake
system which utilizes a Hydro-Max™ hydraulic brake
booster and master cylinder. The system uses DOT 3
Hydraulic Brake Fluid.

Bulletin No.: 18-NA-366

The Bosch® TCS8TA brake system provides the
following vehicle performance enhancement systems:
• Antilock Braking System (ABS).
• Electronic Brake Force Distribution (EBD).
• Drag Torque Control (DTC).
• Traction Control System (TCS).
Brake System Components
The following components are involved in the operation
of the brake system:
• Bosch® TCS8TA Hydraulic unit with attached
electronic brake control module (EBCM).
• The Body Control Module (BCM) monitors the
brake pedal position sensor signal and when the
brake pedal is applied it sends a high speed serial
data message to the EBCM indicating the brake
pedal position.
• The brake pressure sensor is used to sense the
action of the driver application of the brake pedal.
The sensor provides an analog voltage signal that
will increase as the brake pedal is applied. The
EBCM monitors the brake pressure sensor which
is integral to the brake pressure modulator.
• The instrument cluster displays the vehicle speed
based on the information from the engine control
module (ECM). The ECM sends the vehicle speed
information via a high speed serial data to the
BCM. The BCM then sends the vehicle speed
information via a low speed serial data to the
instrument cluster in order to display the vehicle
speed, either in mph or km/h based on the vehicle
parameter that is selected.
ABS
When wheel slip is detected during a brake application,
an 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
increase hydraulic pressure above the amount which is
transmitted by the master cylinder during braking.
During an ABS braking event, a series of rapid
pulsations may be felt in the brake pedal. These
pulsations are caused by the rapid changes in position
of the individual solenoid valves as the EBCM responds
to wheel speed sensor inputs and attempts to prevent
wheel slip. A ticking or popping noise may also be
heard as the solenoid valves cycle rapidly. During ABS
braking on dry pavement, intermittent chirping noises
may be heard as the tires approach the slipping point.
These noises and pedal pulsations are considered
normal during ABS operation.

Bulletin No.: 18-NA-366

November, 2019

ABS Activation Sequence
The typical ABS activation sequence is as follows:
• Pressure Hold: The EBCM closes the isolation
valve and keeps the dump valve closed in order to
isolate the slipping wheel when wheel slip occurs.
This holds the pressure steady on the brake so
that the hydraulic pressure does not increase or
decrease.
• Pressure Decrease: If a pressure hold does not
correct the wheel slip condition, a pressure
decrease occurs. The EBCM decreases the
pressure to individual wheels as needed during
deceleration when wheel slip occurs. The isolation
valve is closed and the dump valve is opened. The
excess fluid is stored in the accumulator until the
pump can return the fluid to the master cylinder or
fluid reservoir.
• Pressure Increase: After the wheel slip is
corrected, a pressure increase occurs. The EBCM
increases the pressure to individual wheels as
needed during deceleration in order to reduce the
speed of the wheel. The isolation valve is opened
and the dump valve is closed. The increased
pressure is delivered from the master cylinder.
Drag Torque Control Operation
During a slip event, the EBCM can send a message to
the ECM to increase engine torque until the driven
wheels are turning at a rate appropriate to the vehicle’s
speed.
Electronic Brake Force Distribution Operation
The slip ratio of each of the vehicle’s wheels is
individually monitored. If any wheel starts to slip, the
brake pressure of each wheel can be modulated so that
the slip ratio remains within a safe range.

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from slipping. The EBCM commands the pump motor
and appropriate solenoid valves ON and OFF to apply
brake pressure to the slipping wheel.
Driver Information — Brake Warning Indicator
The instrument cluster turns the brake warning
indicator ON when the following occurs:
• The instrument cluster performs the bulb check.
• The BCM detects that the parking brake is
engaged. The instrument cluster receives a serial
data message from the BCM requesting
illumination.
• The EBCM detects a faulty pump motor, solenoid
valves, an internal hardware failure or a too high
or too low battery voltage and sends a serial data
message to the instrument cluster requesting
illumination.
Driver Information — ABS / TCS Indicator
The instrument cluster turns the ABS/TCS indicator ON
when the following occurs:
• The instrument cluster performs the bulb check.
• The EBCM detects a malfunction which disables
the ABS and sends a serial data message to the
instrument cluster requesting illumination.
• The driver manually disables the TC by pressing
the traction control switch. The EBCM sends a
serial data message to the instrument cluster
requesting illumination.
Parking Brake System

Hydro-Max™ Operation
The Hydro-Max™ is a hydraulically powered brake
booster which provides power assist for the hydraulic
brakes. A booster combined with a master cylinder
forms the hydraulic brake actuation unit. The booster
which is powered by the power steering pump reduces
the pedal effort required to apply the brakes as
compared to a non-power system. The hydraulic
booster has a backup pump which will provide
hydraulic boost at a reduced rate if the normal source of
fluid is interrupted. The master cylinder is a split system
type with separate fluid chambers, pistons and outlet
ports for the front and rear brake circuits. The master
cylinder includes a differential pressure switch and a
brake fluid level indicator switch.
Traction Control Operation
When drive wheel slip is noted, the EBCM will enter
Traction Control (TC) mode. First the EBCM requests
the 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. If the engine torque reduction does
not reduce drive wheel slip enough, the EBCM will
actively apply the brakes on the slipping drive wheel.
During TC braking, hydraulic pressure in each drive
wheel circuit is controlled to prevent the drive wheels

5169530

The parking brake is a driveline park brake system
consisting of a single drum design (1), mounted around
the propeller shaft and over the brake shoes, forward of
the rear differential. When the parking brake pedal is
depressed, the parking cable is pulled, overcoming
spring pressure within the parking brake and pushing
the brake shoes into contact with the inside of the
parking brake drum. When the operator disengages the
parking brake pedal, spring tension in the parking brake
pulls the park brake shoes to their

Page 8

November, 2019

original (disengaged) position. The parking brake
self-adjusts for brake shoe wear by using a star wheel
mechanism.

Bulletin No.: 18-NA-366

Driver Information Center (Up-Level)

Commercial Link
Overview
Commercial Link enables fleet account owners a better
system to manage their vehicles and improve overall
fleet efficiency. Commercial Link uses the built-in
OnStar® connectivity (must be active) to provide useful
vehicle data, such as maintenance notifications and
vehicle location, in order to better manage mileage and
expenses more effectively. GM is the only auto
manufacturer to offer an embedded vehicle
management solution. Commercial Link is a monthly
subscription with no annual contract. There is also the
option of signing up for invoice payment in increments
of 3 months, 6 months or 1 year.

Driver Information Center
5187070

The DIC displays are shown in the center of the
instrument cluster in the Info app. The displays show
the status of many vehicle systems. The controls for the
DIC are on the right steering wheel control.

Driver Information Center (Base Level)

Engine Duramax® 6.6L V8 — RPO L5D
Overview

5187065

The DIC displays are shown in the center of the
instrument cluster. The displays show the status of
many vehicle systems. The trip odometer reset stem in
the instrument cluster is used to access the DIC menu
items.
5122972

Engine Shown is 2018 Duramax® 6.6L V8 — RPO
L5P (L5D is similar)
The Duramax® 6.6L, V8 — RPO L5D is a turbocharged
diesel engine produced by General Motors for use in
the new 4500HD, 5500HD and 6500HD trucks. The
L5D is part of a new generation of Duramax® engines.
The engine is closely related to the Duramax® 6.6L,
V8 — RPO L5P engine, but is equipped with a smaller
turbocharger and different engine control module
calibrations.

Bulletin No.: 18-NA-366

November, 2019

Engine Features and Specifications
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Bore/Stroke: 4.055 inches (103 mm) /
3.8976 inches (99 mm).
Compression Ratio: 16.0:1
Cooling System: Cooling system flow capacity is
270 L/min at 3,172 RPM.
Connecting Rods: The connecting rods are
one-piece hot forged steel. The connecting rods
and caps are of a fractured split design to improve
durability and reduce internal friction. The
connecting rod small end is tapered cut for
reduced weight and improved durability.
Crankshaft: The crankshaft is a forged steel
design with five main bearings. Crankshaft thrust
is controlled by the number 5 bearing.

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the ports are of a high swirl design for improved
combustion. The cylinder head gaskets consist of
an all steel laminated construction.
Emissions Controls: Cooled Exhaust Gas
Recirculation (EGR), Selective Catalytic
Reduction (SCR), Diesel Particulate Filter (DPF),
intake throttle.
Engine Covers: There is a front engine cover
and a flywheel housing, both are made of
aluminum. The full bell flywheel housing is cross
bolted to the upper oil pan. The flywheel housing
also supplies a crossover passage for engine
coolant. The front engine cover houses the gear
train and provides a mounting surface for the
cooling fan pulley assembly.
Engine Oil Capacity with Filter: Capacity is
10 qt (9.5L).
Exhaust Gas Recirculation: Exhaust gas
recirculation is water cooled for improved
reduction in NOx emissions.
Exhaust Manifold: The exhaust manifolds are a
1-piece cast iron design. The exhaust manifolds
direct exhaust gasses from the combustion
chambers to the exhaust system. Each manifold
has an externally mounted heat shield that is
retained by bolts.
Firing Order: 1-2-7-8-4-5-6-3
Fuel System: Direct injection with high-pressure
common rail. In the diesel engine, air alone is
compressed in the cylinder. Then, after the air has
been compressed, a charge of fuel is sprayed into
the cylinder and ignition occurs, due to the heat of
compression.

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Cylinder Block: The engine block utilizes a deep
skirt design for increased rigidity. The cylinders
are positioned in a 90 degree "V" orientation with
the number one cylinder being the right front. The
block is induction hardened for increased
durability. The crankshaft bearing caps are
cross-bolted to enhance structural rigidity.
Cylinder Head: The cylinder heads are made of
aluminum for lighter weight and rapid heat
dissipation. There are 4 valves per cylinder and

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Fuel Type: GM recommends the use of TOP
TIER Diesel Fuel to keep the engine clean and
reduce engine deposits. Use Ultra-Low Sulfur
Highway Diesel Fuel and/or B20 biodiesel. Fuels

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