Bulletin No.: PIC5836E
Published date: 02/1/2019

Preliminary Information
PIC5836E Rattle or Buzz Noise from Rear Speaker or Speakers Worse with High Bass Levels
Models
Brand:
Cadillac

Model:
ATS

Model Years:
2013 - 2019

VIN:
from
All

Engine:

to
All

All

Transmissions:
All

Supersession Statement
This PI was superseded to update Model Years. Please discard PIC5836D.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition / Concern
Some customers may comment on a rattle or buzz noise from the rear speakers. The noise may
be more easily duplicated with the Bass set to higher levels.
The rear speaker(s) generally is NOT the cause of this issue. Possible causes include:
1. Improper speaker mounting or loose trim, wiring harnesses, or other parts may cause an
audible buzz or distortion.
2. Rattle or buzz from the OnStar module.
3. Seat belt retractor buzz - Center seat belt retractor bolt may be contacting decklid torque
rod inside trunk causing metallic rattle.
4. Child tether cover may be loose in package shelf trim.
5. Package shelf trim and / or trunk upper trim plastic Christmas tree fasteners may buzz to
shelf at attachment holes.
6. Leading edge of package shelf, behind rear seat back.
7. Package shelf "J” hooks loose.

Recommendations / Instructions
The EL-50334-6 Audio System Diagnostic CD contains audio tracks that can be used to
duplicate and isolate such concerns. Tracks 11 and 12 contain audio sweep tones for testing
for speaker and grill rattles.
1. Inspect the rear speaker and the surrounding interior trim for proper and secure mounting.
If the speaker trim has come loose, replace the speaker. If surrounding interior trim is found to
be loose or improperly secured, correctly secure the item and add foam to insulate items as
needed. Add foam to the subwoofer speaker connector to prevent contact to the under shelf
trim from making contact. Use ½” by 5/16” of Kent Adhesive Backed Shim Stock (foam) p/n
P40125 or equivalent.

2. OnStar module - place 1/4" foam pad underneath the module (if foam is not currently in
place). Use (4) 1” x 6”x 5/16” thick strips of Kent Adhesive Backed Shim Stock (foam) p/n
P46510 or equivalent.
Note: Do not apply foam the beyond the base of the module, avoid adding the foam in the area
of the mounting flanges.

3. Seat belt retractor buzz - Ensure the existing foam torsion spring cover is centered on the
deck lid torque rods. Use a zip tie to secure. Add a piece of 3/8” rubber hose (fuel line) to the
center belt rear mounting bolt. See pictures below. Note hose on seat belt bolt left side
behind torsion spring.

4. Add felt onto the package shelf trim opening to prevent movement between the trim and
the child seat tether cover if the felt is not present. Use Kent Adhesive Backed Flocking Tape
p/n KT13295 or equivalent see pictures below.

5. Add foam grommets onto each of the Christmas tree fasteners (if not present) prior to
reinstalling back into the package shelf sheet metal holes. Use 1” X 1” block of Kent Adhesive
Backed Shim Stock p/n P46510 or equivalent to create a foam washer(s) as needed. Fold the
1” x1” block over from corner to corner and carefully cut a hole in the center of the block to
create a washer/spacer, see pictures below.

6. Add two ¾” by 1 1/2 “ long by 7/16” thick of Kent Adhesive Backed Shim Stock (foam) p/n
P46505 or equivalent centered between the retaining clips on the leading edge of the package
shelf (behind/under the rear seat back) see picture below.

7. Check the “J” hooks of the package shelf cover/trim for being secure. See picture below.
Use hot glue to resecure the “J” hooks as needed.

Warranty Information
The correction for this concern may be one of several repairs described above. For vehicles
repaired under warranty, please use the appropriate warranty labor operation based on the
actual cause and repair.

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

Labor Operation

Description

Labor Time

3480038*

Audio System Diagnostics Using EL-50334-6 Audio
0.2 hr
System Diagnostic CD

Add

To Remove Rear Package Shelf Trim

Add

Add Foam to Rear Speaker and/or Surrounding Trim
0.2 hr
(After Rear Shelf Trim Removed)

Add

Install Foam Pad Underneath the Onstar Module
(After Rear Shelf Trim Removed)

Add

Add Foam Grommets Onto Each of the Christmas
Trees For the Rear Package Shelf (After Rear Shelf 0.2 hr
Trim Removed)

Add

Add Felt Onto the Package Shelf Trim Opening

0.2 hr

Add

Add Rubber Hose to End of Bolt

0.1 hr

1.2 hr

0.2 hr

* This is an unique labor operation for bulletin use only. This will not be published in the Labor
Time Guide.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is
resolved without completing every step, the remaining steps do not need to be performed.

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