18NA033

Bulletin No.:
Service Bulletin
Date:
18-NA-033
December, 2021
INFORMATION
Subject:
Diagnostic Tip for Low Oil Pressure Light on at Idle
This bulletin replaces PI0909B. Please discard PI0909B.
Brand:
Model:
Buick
Chevrolet
Pontiac
Saturn
Model Year:
VIN:
from
to
Encore
2013
2021
Aveo
2009
2011
Cruze
2011
2018
Sonic
2012
2020
Trax
2013
2021
G3
2009
2010
Wave
2009
2010
Astra
2008
2009
from
to
—
—
Engine:
Transmission:
LUJ, LUV,
LUW, LWE,
LXV, 2HO
—
Involved Region or Country
North America
Condition
Some customers may comment on the low oil pressure light coming on or flashes on and
off at idle.
Cause
This condition may be caused by oil pressure being bled off due to debris in the oil drain
check valve and/or a damaged oil filter.
Correction
Use a manual pressure gauge to check oil pressure:
• If the pressure is low, perform a visual inspection of the condition of the oil filter.
• If the condition of the oil filter is good, remove the filter and confirm proper operation of
the oil filter drain check valve.
• If the valve does not seal or it is held open, repair as necessary and recheck oil
pressure.
Copyright 2021 General Motors LLC. All Rights Reserved.
Page 2
December, 2021
Condition/Symptoms
Bulletin No.: 18-NA-033
illustration above. This will allow oil to drain back into
the oil pan and reduce the pressure allowed to the
engine.
3283232
During an oil change, it is possible for the tabs on the
oil filter, as shown in the illustration above, to break off
and fall into the oil filter housing.
3512218
3512219
3283221
This piece may become lodged under the oil filter
housing drain check valve, causing it to remain open
when the new filter is installed as shown in the
Shown in the illustrations above is an oil filter that was
installed improperly, which caused the oil filter to be
smashed and cannot close the oil filter drain check
valve.
Version
2
Modified
Released February 2, 2018
December 02, 2021 – Added the 2019-2021 Model Years to Encore and Trax and 20192020 Model Years to Sonic.
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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