21NA265

Bulletin No.:
Service Bulletin
Date:
21-NA-265
November, 2021
TECHNICAL
Subject:
Coolant Leak Under Truck, Malfunction Indicator Lamp (MIL) Illuminated - DTC
P2C48 Set
Brand:
Model:
Chevrolet
Silverado 2
500HD/3500HD
GMC
Sierra
2500HD/3500HD
Model Year:
from
to
2020
2022
VIN:
from
to
Engine:
Transmission:
L5P
Involved Region or Country
North America, Middle East, Israel, Australia, New Zealand
Condition
Some customers may comment on one or more of the following conditions:
• Coolant leak under the vehicle
• MIL illuminated
Some technicians may find DTC P2C48 set in the Engine Control Module (ECM).
Copyright 2021 General Motors LLC. All Rights Reserved.
Page 2
Cause
November, 2021
Bulletin No.: 21-NA-265
This condition may be caused by the fuel cooler coolant hose contacting front drive shaft
at crossmember.
– Typically can happen when driving through deeper water or snow.
Follow the procedure below to re-route the coolant hose away from the front drive shaft:
5924533
Correction
1. Utilizing a 6.5 mm drill size, drill a hole in the transmission crossmember in the
approximate location noted in the graphic above.
5924534
2. Add retainer or equivalent, onto the hose.
3. Install retainer into the hole in the crossmember.
Bulletin No.: 21-NA-265
November, 2021
Page 3
Parts Information
Causal Part
Description
Part Number
Qty
N/A
Retainer
13596790 (Hollingsworth)
1
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.
Labor Operation
Description
Labor Time
4088308*
Drill Hole in Crossmember and add Clip
0.5 hr
*This is a unique Labor Operation for Bulletin use only.
Version
1
Modified
Released November 18, 2021
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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