File in Section:
Bulletin No.:

Service Bulletin

Date:

16-NA-079
March, 2018

TECHNICAL
Subject:

Audio System Speaker Rattle, Buzz Noise, Poor Sound When Playing Radio or Other
Music Source

Brand:

Model:

Chevrolet
GMC

Model Year:

VIN:

Engine:

Transmission:

2018

All

All

2018

All

All

from

to

Colorado

2015

Canyon

2015

from

to

Condition

Some customers may comment that the audio speaker sound quality is poor, has a
buzzing sound or rattles while listening to the radio or other music source.

Cause

This condition may be caused by the trim, moldings or water deflectors located in the
area of the speaker.

Correction
Important: Do not remove any trim or door panels
prior to performing the following diagnostic procedure
because removal may mask the concern.
1. Before beginning the diagnosis, determine the
operating conditions that are contributing to the
condition. Ask the customer the following
questions:
• Determine the type of music the customer is
listening to (Rock, country, Rap, Hip-Hop, etc).
• Which source was being used when the
condition occurred (FM, AM, CD, USB, Aux).
• When did the condition occur, only in the
morning? After sitting in the sun?
• Determine the temperature of the vehicle when
the condition occurs. Was is cold outside? Only
after the vehicle heated up?
• What area of the vehicle did the noise
come from?
• Was there anything else in the vehicle when the
condition occurred? Packages? Loose items?
2. Check for any audio system related DTCs – if there
are any DTCs, follow the SI diagnostic procedure.
3. Music CDs do not hold tone long enough to
diagnose trim rattles. Obtain GM Test CD part
number # J39916-CD (SPX, 1-800-345-2233).
There may be certain audio frequencies such as
bass that can cause buzz or rattle in the interior
trim. Most trim rattles are caused by bass
frequencies in the range of 50-80 Hz and are found
on track 3.

Copyright 2018 General Motors LLC. All Rights Reserved.

Note: For use in vehicles that no longer have a CD
player, the test tones on the CD can be copied to a USB
drive or other device to use during testing. The test
tones on the J-39916-CD and EL-50334-6 CD also can
be downloaded from gmtoolsandequipment.com. (refer
to May 2017 TechLink article titled "Using the Audio
Diagnostic Tracks on a USB Drive")
4. Insert the GM Test CD/USB and play various
tracks corresponding to the type of music the
customer was listening to when the condition
occurred and verify the condition.
5. Hold the volume at a constant level and use the
balance and fader controls to isolate the
speaker(s) that are experiencing the condition.
6. If complaint is from a specific door, make sure all
other doors are shut and all windows are in the up
position. From inside the truck, open and close the
suspect door with some force and listen for any
buzzes or rattles. If there is noise when closing the
door then proceed to root cause noise prior to any
speaker repair.
7. Apply hand pressure to the trim in the area of
concern.
8. If the sound changes when the trim is depressed or
manipulated by hand, then the trim is causing the
rattle or buzz.

Page 2

March, 2018

Door Trim/Water Deflector/Harness Rattle

Loose Trim, Panel to Panel Contact

4426926

An interface may cause a rattle or buzz (for example,
between a door and instrument panel).
• To better identify the location, open the door and
determine if the buzz or rattle follows the door.
This may be caused by loose door trim, water
deflector contact with the trim, or wire harness
conduit coming into contact with the inner door
sheet metal. Refer to Door Trim/Water Deflector/
Harness Rattle below.
• Determine if a rattle is heard between the
instrument panel and door. This may be caused by
contact between the instrument panel and the
door trim when the door is closed. If the noise
goes away when the door is opened, inspect the
trim panel on the door to ensure it is in the correct
position. Also, inspect the snap-on trim panels on
the instrument panel ends to ensure they are fully
engaged into the instrument panel.
Note: When removing door trim verify that all screws
where firmly secured and all clips engaged without any
damage to the clips.
•

Bulletin No.: 16-NA-079

4426929

If the rattle is heard within the door trim, check the
locations shown above by depressing the trim with your
hand. If the sound changes or the rattle/buzz
decreases when pressure is applied, follow the steps
below.

If the rattle or buzz is determined to be coming
from the instrument panel, inspect for loose
panels, screw covers or contact between trim
panels such as an A pillar to instrument panel
interference.

2811998

•

•

•
•

Remove the door trim screw cover behind the door
handle on the affected door and apply pressure to
the water shield. If this cures the condition, refer to
the water shield procedure below.
Once the door trim is removed, confirm the
perimeter clips are not damaged, bent or missing.
Replace damaged door clips. Add flocking tape as
needed.
Remove any loose tape from harnesses or cables
and part tags/stickers from door trim.
Visually inspect to see if the wire harness conduit
is rattling against the inner door sheet metal.

Bulletin No.: 16-NA-079

•

March, 2018

If the conduit is coming in contact with the inner
door sheet metal, apply adhesive backed foam
shim stock such as *Kent Industries Part #
P46515 or the equivalent, to the sheet metal to
correct the condition.
Inspect the bottom of door for any loose material.
Remove vapor barrier/water deflector and ensure
all harnesses and cable are properly routed and
push pins fully seated.

Page 3

Note: The foam shipping blocks installed on new
vehicle door edges can be used for the above step.
•

Reinstall all components and verify the condition
is corrected using the same audio source that
created the condition.
* We believe these sources and their products to be
reliable. There may be additional manufacturers of
such material. General Motors does not endorse,
indicate any preference for or assume any
responsibility for the products from these firms or for
any such items which may be available from other
sources.

Parts Information
*Call 1-888 Yes-Kent for ordering information.
Description

Part Number

1” x 9/16” Adhesive Backed Foam
Shim Stock

*P46515

Warranty Information
For vehicles repaired under the Bumper-to-Bumper
coverage (Canada Base Warranty coverage), use the
following labor operation. Reference the Applicable
Warranties section of Investigate Vehicle History (IVH)
for coverage information.
2811996

•

If the rattle is caused by the water shield, install
two 100 mm (4 in) long layers of 1” x 9/16”
adhesive backed foam shim stock such as *Kent
Industries Part # P46515 or the equivalent, to
compress the water shield as shown. Confirm any
added foam does not interfere with the window or
door lock operation.

Labor
Operation

Description

Labor Time

3480008*

Diagnose and Repair Audio
System Speaker Concerns

Use Actual
Clock Time

*This is a unique Labor Operation for Bulletin use only.

Version

3

Modified

July 11, 2016 – Added condition of the wiring harness conduit rattle to door metal inner.
March 22, 2018 — Added 2017 and 2018 Model Years.

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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