19NA237

Bulletin No.:
Service Bulletin
Date:
19-NA-237
October, 2019
INFORMATION
Subject:
Diagnostic Tip - Diesel Exhaust Fluid System Contamination
This bulletin replaces PIP5370D. Please discard PIP5370D.
Brand:
Chevrolet
GMC
Model:
Model Year:
VIN:
from
Engine:
from
to
Colorado
2016
2020
2.8 LWN
Cruze
2014
2015
2.0 LUZ
Cruze
2017
2018
1.6 LH7
Equinox
2018
2019
1.6 LH7
Express
2010
2016
6.6 LGH
Express
2017
2020
2.8 LWN
Silverado
2011
2018
6.6 LGH
and LML
Silverado
1500
2020
2020
3.0 LM2
Silverado
2500/3500
2019
2020
6.6 LP5
Transmission:
to
Canyon
2016
2020
2.8 LWN
Savana
2010
2016
6.6 LGH
Savana
2017
2020
2.8 LWN
Sierra
2010
2018
6.6 L5P, LGH
and LML
Sierra 1500
2020
2020
3.0 LM2
Sierra
2500/3500
2019
2020
6.6 LP5
Terrain
2018
2019
1.6 LH7
Involved Region or Country
North America
Condition
Some customers may comment on one or more of the following conditions:
• Exhaust fluid quality poor message on the Driver Information Center (DIC).
• Diesel exhaust fluid warning lamp on.
• Other exhaust fluid quality related concerns.
Cause
This condition may be caused by contamination in the diesel exhaust fluid (DEF) system
and it's components.
Copyright 2019 General Motors LLC. All Rights Reserved.
Page 2
October, 2019
Bulletin No.: 19-NA-237
Note: Please follow this diagnostic or repair process thoroughly and complete each step.
If the condition exhibited is resolved without completing every step, the remaining steps
do not need to be performed.
Correction
Refer to SI for Contaminants in Diesel Exhaust Fluid Diagnosis and use special tools
J26568 Coolant and Battery Fluid Tester or EN50422 Diesel Exhaust Fluid Refractometer
for fluid testing.
Note: All 2017 and newer model year diesel vehicles, with the exception of the Colorado
and Canyon, are equipped with a DEF quality sensor integrated into the DEF tank. The
value of this sensor can be read with the scan tool in the reductant data as the Reductant
Concentration.
Information
Below are examples of DEF mixed with different
sources of contamination.
4373642
Diesel Exhaust Fluid (DEF) mixed with Diesel Fuel.
4373640
Diesel Exhaust Fluid (DEF) mixed with Brake Fluid.
4373644
Diesel Exhaust Fluid (DEF) mixed with Engine Oil.
4373641
Diesel Exhaust Fluid (DEF) mixed with Dexcool.
Bulletin No.: 19-NA-237
October, 2019
Page 3
4373645
Diesel Exhaust Fluid (DEF) mixed with Power Steering
Fluid.
4373647
Diesel Exhaust Fluid (DEF) mixed with Windshield
Washer Fluid.
4373646
Diesel Exhaust Fluid (DEF) mixed with Transmission
Fluid.
4373648
Diesel Exhaust Fluid (DEF) mixed with Water.
Page 4
October, 2019
Bulletin No.: 19-NA-237
Warranty Information
This bulletin is being published to help technicians
identify signs of contamination in Diesel Exhaust Fluid
(DEF). If you see evidence of contamination take
appropriate measures to ensure that all of the
contaminated fluid is removed from the vehicle. Any
components that have failed as a result of
contamination should NOT be covered by warranty.
Version
1
Modified
Released October 17, 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.
WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION