21NA095

Bulletin No.:
Service Bulletin
Date:
21-NA-095
February, 2022
TECHNICAL
Subject:
Malfunction Indicator Lamp (MIL) Illuminated - DTC P1488 or P24DA Set
Brand:
Model:
Cadillac
from
to
Escalade Models
2021
2022
Silverado 1500
2020
2021
Silverado 1500 2WD (LTD, RPO J21,
12th VIN Digit = 4
or less)
Chevrolet
Silverado 1500 2WD (RPO J22, 12th
VIN Digit = 5 or
greater)
Suburban
Tahoe
Sierra 1500
GMC
Model Year:
Sierra 1500 - 2WD
(LTD, RPO J21, 12th
VIN Digit = 4 or less)
Sierra 1500 - 2WD
(RPO J22, 12th VIN
Digit = 5 or greater)
Yukon Models
VIN:
from
Engine:
Transmission:
to
2022
2022
LM2
2021
2020
2022
2021
2022
2021
Involved Region or Country
North America, Uzbekistan, Russia, Middle East, Chile (West), Colombia (West),
Ecuador (West), Paraguay (West), Peru (West), Venezuela (West), Japan, Cadillac
Korea (South Korea), Thailand (ASEAN), Australia/New Zealand
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 can be caused by any exhaust leak, but is primarily caused by an exhaust
leak between the NOx catalytic converter and the rear exhaust pipe.
Correction
Refer to the Service Procedure.
Copyright 2022 General Motors LLC. All Rights Reserved.
Page 2
February, 2022
Bulletin No.: 21-NA-095
Service Procedure
5795155
1. Separate the rear exhaust pipe from the NOx
catalytic converter and discard clamp.
2. Utilizing an abrasive cloth or equivalent, clean the
outside of the NOx catalytic converter pipe and the
inside and outside of the rear exhaust pipe.
5811457
Note: It is extremely important that the pipes are clean
and free of rust or the tape will not stick.
3. Utilizing Tiger/Spider Patch Tape or equivalent,
fold the tape in half and cut down the middle the
entire length.
Bulletin No.: 21-NA-095
February, 2022
Page 3
5795164
Note: Apply the patch to the edge of the pipe.
4. Wrap the joint end of the cleaned NOx catalytic
converter pipe approximately 1.5 Times with the
tape and cut off excess.
5. Reconnect the rear exhaust pipe to the NOx
catalytic converter and verify proper alignment.
6. If the rear exhaust pipe does not line up with the
end of the NOx catalytic converter, it may be
necessary to support the rear exhaust pipe and
disconnect the exhaust hangers so that the two
pipes line up. The key is to draw both pipes
together prior to taping and clamping the joint.
5795191
Important: It is very important that the rear exhaust
pipe is fully seated in the NOx catalytic converter cone
prior to taping the joint.
Note: Tape should be placed evenly between the rear
exhaust pipe and the NOx catalytic converter..
7. Once joined, wrap the joint 1.5 Times with Tiger/
Spider Patch Tape and cut off excess.
Page 4
February, 2022
5795194
8. Install the new clamp.
⇒ Tighten clamp to 28 Y (21 lb ft).
9. If any of the exhaust hangers were disconnected in
step 6, re-secure them.
10. Drive the vehicle approximately 20 minutes to
allow the Tiger/Spider Patch to heat up and seal.
11. After driving, allow 30 minutes for the tape to cool
and fully cure.
5795157
Bulletin No.: 21-NA-095
Bulletin No.: 21-NA-095
February, 2022
Page 5
Parts Information
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
6
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.
Revised September 17, 2021 - Updated the Cause and Correction sections.
Revised January 18, 2022 - Add 2022 to Model Year and Added Additional Regions and
Countries.
Revised January 28, 2022- Update Service Procedure section.
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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