21NA095

Service Bulletin
Bulletin No.:
21-NA-095
Date:
June, 2021
TECHNICAL
Subject:
Malfunction Indicator Lamp (MIL) Illuminated - DTC P1488 or P24DA Set
Model Year:
Brand:
Model:
Cadillac
Escalade Models
2021
Silverado 1500
2020
Chevrolet
Suburban
Tahoe
GMC
from
2021
Sierra 1500
2020
Yukon Models
2021
to
2021
VIN:
from
Engine:
Transmission:
to
LM2
Involved Region or Country
North America
Condition
Some customers may comment that the MIL is illuminated.
Some technicians may find DTC P1488 or P24DA (Particulate Matter Sensor Protection
Tube Performance) set in the Engine Control Module (ECM).
Cause
This condition may be caused by exhaust leak between the Under Floor Selective
Catalyst Reduction (UFSCR) and Tailpipe.
Correction
If an exhaust leak has been found, separate the pipe and apply Tiger Patch tape.
Service Procedure
5795155
Copyright 2021 General Motors LLC. All Rights Reserved.
Page 2
June, 2021
Bulletin No.: 21-NA-095
1. Separate the UFSCR/Tailpipe Assembly and
discard clamp.
2. Utilizing an abrasive cloth or equivalent, clean the
surfaces of the pipes.
5811457
3. Utilizing Tiger/Spider Patch Tape or equivalent,
fold the tape in half and cut down the middle the
entire length.
5795164
Note: Apply the patch to the edge of the pipe.
4. Wrap the joint approximately 1.5 Times with the
tape and cut off excess.
5. Reconnect UFSCR and Tailpipe, verify for proper
alignment and insertion.
6. Use securing method to hold the UFSCR/Tailpipe
assembly in place and along the center line axis.
Bulletin No.: 21-NA-095
June, 2021
Page 3
5795191
Note: Tape should be placed evenly between UFSCR
and Tailpipe components.
Parts Information
7. Once secured, wrap the joint again 1.5 Times with
Tiger/Spider Patch Tape and cut off excess.
5795194
8. Install the new clamp.
⇒ Tighten clamp to 28 Y (21 lb ft).
9. Drive vehicle approximately 20 minutes to allow
the Tiger/Spider Patch to heat up and seal.
5795157
Page 4
June, 2021
Bulletin No.: 21-NA-095
Causal Part
Description
Part Number
Qty
Material Allowance
N/A
Versachem, Tiger
Patch Tape* (U.S. only)
10270
1
$6.00
N/A
Versachem, Spider
Patch Tape*
(Canada only)
90352
1
$11.00
N/A
CLAMP, EX
84283544
1
-
*There is enough material to repair additional vehicles. Store the remaining material for future use.
Warranty Information
For vehicles repaired under the Emission coverage,
use the following labor operation. Reference the
Applicable Warranties section of Investigate Vehicle
History (IVH) for coverage information.
Labor Operation
Description
Labor Time
4087988*
Diagnostic and Smoke Test
0.5 hr
Add
Apply Exhaust Patch Tape to UFSCR/Tailpipe Flange
1.0 hr
*This is a unique Labor Operation for Bulletin use only.
Version
3
Modified
Released April 22, 2021
Revised May 03, 2021 - Changed P42DA to P24DA and Changed Region Information to
North America.
Revised June 04, 2021 - Add Spider Patch information to Service Procedure and Parts
information section and Removed the Information to Allow the Tape to Overhang the Pipe
to Apply Tape to the Edge of Pipe.
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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