Service Bulletin

Bulletin No.:

19-NA-122

Date:

June, 2019

TECHNICAL
Subject:

Rough Running Engine, Malfunction Indicator Lamp (MIL) Illuminated - DTC P0300 Set
This Bulletin replaces PIP5421G. Please discard PIP5421G.

Brand:

Model:

Chevrolet

Malibu

Model Year:

VIN Breakpoint:

from

to

from

to

2016

2017

SOP

HF214702

Engine:

Transmission:

1.5L (LFV)

Involved Region or Country

North America, Israel

Condition

Some customers may comment on one or more of the following conditions:
• Rough running engine
• MIL illuminated
Some technicians may find DTC P0300 (Engine Misfire Detected) set along with a misfire
low compression in one or more cylinders.

Cause

This condition may be caused by a damaged piston.

Correction

Repair the engine mechanical concern based on the results of the Service Procedure
testing below.

Service Procedure
Important: This bulletin does not apply to 2017
vehicles built with VIN sequence HF214702 and higher
as they have the updated piston assemblies installed.
Repair the engine mechanical concern based on the
results of the Service Procedure below.
Note: To isolate the source of cylinder leakage to a
valve or cylinder sealing issue, it may be necessary to
remove the intake and exhaust manifolds.
1. Perform Engine Compression Testing in SI.
2. If low compression is found, perform Cylinder
Leakage Testing in SI and record the test results to
isolate the concern.
• If excessive leakage to the crankcase is
isolated, check piston and cylinder wall
condition.
• If the cylinder wall surface has not been
compromised, replace all four piston and rod
assemblies.

Copyright 2019 General Motors LLC. All Rights Reserved.

3. Fill the crankcase with current specification Dexos
oil (Refer to Corporate Bulletin Number
16-NA-367).
4. Check that the vehicle is up to the latest released
calibration available.
⇒ If not, reprogram the engine control
module (ECM).
An un-metered air leak in the induction system, or an
engine mechanical issue causing rough running, may
cause the ECM to learn an incorrect Throttle Body Idle
Airflow Compensation value over time.
This incorrectly learned value may cause various
symptoms to occur such as MIL on with P1101 setting,
rough or unstable idle speeds and/or engine stall.
Once the mechanical repairs have been completed,
perform Throttle Body Inspection and Cleaning in SI,
followed by Throttle Body Idle relearn and Air Flow
Compensation Reset function in GDS2.

Page 2

June, 2019

Bulletin No.: 19-NA-122

Examples of pistons with varying levels of
damage:

4576900

4576919

4576895

4576909

Bulletin No.: 19-NA-122

June, 2019

Page 3

Examples of light vertical marks visible on the
cylinder wall:

4573921

4576902

None of the marks in the cylinder walls could be felt
with the fingernail and engine replacement is not
recommended.

Example of a damaged cylinder wall:

4573920

4576914

In this example, the scuffing is wide and has removed
the crosshatch from the cylinder wall in the area above
the arrow.
This would result in oil consumption and requires
engine replacement.

Page 4

June, 2019

Parts Information

Warranty Information

Causal
Part

Description

Part
Number

Qty

X

Piston

12674549

4

Bearing Kit

12674806

4

Gasket Kit

12687228

1

Seal, Cr/sft Frt

12661527

1

N/A

Filter

12696048

1

Gasket, O/Pmp

12644557

1

Gasket, O/Pmp

12644558

1

Pan

12637773

1

Pipe, Fuel

12684046

1

Gasket, Manifold

12637018

1

Gasket,
Ctltc Conv

12641115

The correction for this concern may be one of several
repairs described above. For vehicles repaired under
warranty, please use the appropriate warranty Labor
Operation based on the original cause in addition to
well documented straight time.

1

Shield, Heat

12673929

1

Seal, Turbo Cool

12662185

4

Fitting,
Turbo Cool

12676405

Washer

12662184

2

Fitting, Turbo Pipe

12685113

1

Gasket, Turbo Oil

12653753

1

Gasket, Turbo Oil

12640468

1

Seal Kit, F/Injn

12659782

1

Seal, F/Pmp

12645181

1

Gasket, Wat Out

12627061

1

Gasket, Therm

12635750

1

Gasket, Exh

23238284

1

Gasket, Exh

22816982

1

Bolt, Cr/Shf

11611070

1

Nut, Turbo

11546365

4

Bolt, Fuel Pmp

11588724

2

Bolt, Eng Mnt

11547918

3

Bolt, Eng Mnt

11588754

3

Oil, Engine

Bulletin No.: 19-NA-122

1

Refer to EPC

Version

1

Modified

Released May 30, 2019

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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