18NA246

Bulletin No.:
Service Bulletin
Date:
18-NA-246
February, 2019
TECHNICAL
Subject:
Malfunction Indicator Lamp (MIL) Illuminated - DTC P0172 Set
Attention: This bulletin applies to the vehicles that have fuel enriched engine oil due to short
driving intervals.
Brand:
Buick
Cadillac
Chevrolet
GMC
Model:
Model Year:
from
Envision
2016
Regal
2014
ATS
2013
CTS
2014
Camaro
2016
Equinox
2018
Malibu
2013
Traverse
2018
Terrain
2018
VIN:
to
2019
from
to
Engine:
Transmission:
Equipped with
2.0L
(RPO LTG)
Involved Region or Country
North America
Condition
Some customers may comment that the MIL is illuminated.
Some technicians may find DTC P0172 (Fuel Trim System Rich) set in the Engine
Control Module (ECM).
Cause
Correction
This condition may be caused by driving the vehicle in short intervals, allowing excessive
fuel to collect in the crankcase.
Important: This service procedure is for vehicles that have fuel enriched engine oil due
to frequent short trip operation. Replacing fuel components such as the high pressure fuel
pump or fuel injectors will not correct the setting of P0172 under the operating conditions
described unless those components can be verified as causing a fuel rich condition.
If fuel in the engine oil has been confirmed to be caused by frequent short trip operation,
refer to the Service Procedure below.
Service Procedure
Important: Perform all of the procedures below that
apply to the model year of the vehicle being worked on.
For 2016-2018 Model Years:
Note: Stable battery voltage is critical during
programming. Any fluctuation, spiking, over voltage or
loss of voltage will interrupt programming. Install a GM
Authorized Programming Support Tool to maintain
system voltage. Refer to www.gmdesolutions.com for
further information. If not available, connect a fully
Copyright 2019 General Motors LLC. All Rights Reserved.
charged 12 V jumper or booster pack disconnected
from the AC voltage supply. DO NOT connect a battery
charger.
1. Program ECM to the latest software available.
Refer to K20 Engine Control Module: Programming
And Setup in SI.
Page 2
February, 2019
Bulletin No.: 18-NA-246
For 2016-2019 Model Years:
5207126
Note: The graphic above compares the old style
primary PCV valve (A) to the revised PCV valve (B).
3. Apply a light coating of oil to the revised PCV valve
O-ring.
5207717
4. Using hand pressure, install the PCV valve into the
cover until seated into bore.
5. Install the camshaft cover.
4244907
1. Remove the camshaft cover (3). Refer to Camshaft
Cover Replacement in SI.
2. Remove the PCV valve from the cover.
Bulletin No.: 18-NA-246
February, 2019
Page 3
Parts Information
2013-2019 Model Years
Note: An oil and filter change is necessary to remove
excessive fuel collected in the crankcase and correct
the DTC set.
1. Perform an oil change. Refer to Engine Oil and Oil
Filter Replacement in SI.
2. Clear the code and take the vehicle for a test drive
to validate that the code does not return.
Important: If the customer continues to frequently
operate the vehicle in this manner, they MUST change
the engine oil and filter more frequently than the oil life
monitor indicates. How often the customer must
change the engine oil is based on how they operate the
vehicle.
Causal
Part
Description
Part
Number
N/A
Filter, Oil
N/A
Oil
Refer
to EPC
1
N/A
VALVE, PCV
(Primary)
55596783
1
Warranty Information
Important: Only select the labor operation that
coincides with the repair performed.
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
Model
Description
Labor Time
4086338*
All
Diagnosis MIL and
Clear Code
0.2 hr
Add
All
Oil and Filter Change
0.3 hr
Add
Envision
Camshaft Cover Removal and
Install
1.6 hrs
Add
Regal
Camshaft Cover Removal and
Install
1.5 hrs
Add
ATS
Camshaft Cover Removal and
Install
3.9 hrs
Add
CTS
Camshaft Cover Removal and
Install
3.7 hrs
Add
Camaro
Camshaft Cover Removal and
Install
3.9 hrs
Add
Equinox
Camshaft Cover Removal and
Install
1.6 hrs
Add
Malibu
Camshaft Cover Removal and
Install
3.6 hrs
Add
Traverse
Camshaft Cover Removal and
Install
4.0 hrs
Add
Terrain
Camshaft Cover Removal and
Install
1.6 hrs
Add
All
Install Primary PCV Valve
0.1 hr
2886148*
All
Engine Control Module
Reprogramming with SPS for
DTC P0172 Set
0.5 hr
*This is a unique Labor Operation for Bulletin use only.
Qty
Page 4
February, 2019
Bulletin No.: 18-NA-246
Version
3
Modified
Released August 06, 2018
January 30, 2019 – Added an Attention statement, updated the Models section,
Correction, Service Procedure and Parts and Warranty Information.
February 14, 2019 – New Labor Operation number requested for ECM programming
under Warranty Information 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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