21NA030

Service Bulletin
Bulletin No.:
21-NA-030
Date:
April, 2021
TECHNICAL
Subject:
Engine Noise and/or Belt Squeak, MIL Illuminated – DTC P0324 Set
This bulletin replaces PIP5545C. Please discard PIP5545C.
Brand:
Buick
Cadillac
Chevrolet
GMC
Holden
Model:
Model Year:
Breakpoint:
from
to
LaCrosse
2017
2019
Regal
2018
2020
ATS
2016
2019
CT6
2016
2020
CTS
2016
2019
XT5
2017
2021
XT6
2020
2020
Blazer
2019
2021
from
to
Engine:
3.6L (LGX)
3.0L (LGW),
3.6L (LGX)
SOP
October
30, 2020
3.6L (LGX)
Camaro
2016
2019
Colorado
2017
2021
3.6L (LGZ)
Acadia
2017
2019
3.6L (LGX)
3.6L (LGZ)
Canyon
2017
2021
Commodore
2018
2020
Acadia
2017
2019
Involved Region or Country
Condition
Transmission:
—
—
—
3.6L (LGX)
North America, Europe, Russia, Middle East, Iraq, Israel, Palestine, Argentina, Brazil,
Bolivia, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay, Venezuela, Japan, Cadillac
Korea (South Korea), GM Korea Company, China, Taiwan, Thailand, Singapore,
Philippines, Australia/New Zealand, Egypt, Other Africa, South Africa
Some customers may comment on one or more of the following conditions:
• MIL illuminated
• Engine noise from the front of engine
• Belt Squeak
Note: This noise may or may not be present at the time vehicle comes in.
Some technicians may find DTC P0324 (Knock Sensor System Performance) set in the
Engine Control Module (ECM).
This condition may be caused by the water pump.
Cause
Copyright 2021 General Motors LLC. All Rights Reserved.
⇒ If the condition is bad enough, the engine will pick up knock noise created by
the water pump.
Page 2
April, 2021
Bulletin No.: 21-NA-030
If this condition is found, perform the following inspections prior to diagnosing per SI.
1. Listen to the water pump with a stethoscope or chassis ears to see if any unusual
noise is heard. Compare to similar vehicle to confirm.
2. Watch the knock re-tard bank to bank on GDS2, then remove the belt and observe
knock re-tard again.
– If there is a difference, this bulletin applies.
– If no noises are heard or there is no difference in knock re-tard, then this bulletin
does not apply. Refer to SI for further diagnostics.
If a noise is heard or a difference is made removing the belt, then replace the water pump
and re-evaluate the concern.
Correction
Service Procedure
Refer to Water Pump Replacement in SI.
Parts Information
Causal
Part
X
Description
Part
Number
PMP KIT,
WAT (LGX)
12707180
PMP KIT,
WAT (LGZ)
12679360
Qty
1
Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation
4032750
Description
Labor Time
Water Pump Replacement
Use
Published
Labor
Operation
Time
Version
2
Modified
Released February 08, 2021
April 09, 2021 – Added RPO LGZ to Colorado and Canyon.
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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