19NA237

Bulletin No.:
Service Bulletin
Date:
19-NA-237
January, 2022
INFORMATION
Subject:
Diagnostic Tip - Diesel Exhaust Fluid System Contamination
This bulletin replaces PIP5370D. Please discard PIP5370D.
Brand:
Model:
Cadillac
Escalade Models
VIN:
to
2020
2022
LM2
2014
2015
LUZ
2017
2019
LH7
Colorado
2016
2022
LH7
Equinox
2018
2019
LH7
2010
2016
LGH
2017
2022
LWN
2011
2016
LML
2017
2018
L5P
Silverado 1500 4WD (New Model,
12th VIN Digit = 7)
2019
2019
Silverado 1500
2020
2021
Express
Silverado
Silverado 1500 (LTD,
RPO J21, 12th VIN
Digit = 4 or less)
from
to
Engine:
from
Cruze
Chevrolet
Model Year:
LM2
Silverado 1500 2WD (LTD, RPO J21,
12th VIN Digit = 4
or less)
2022
2022
Silverado 2500/3500
2019
2022
L5P
Silverado 4500HD,
5500HD and 6500HD
2019
2022
L5D
Silverado LD
2019
2019
L5P
Suburban
2020
2022
LM2
Tahoe
2020
2022
LM2
Copyright 2022 General Motors LLC. All Rights Reserved.
Transmission:
Page 2
January, 2022
Brand:
Model:
Savana
Sierra
Sierra 1500
GMC
Sierra 1500 (LTD,
RPO J21, 12th VIN
Digit = 4 or less)
Sierra 1500 - 2WD
(LTD, RPO J21, 12th
VIN Digit = 4 or less)
Model Year:
Bulletin No.: 19-NA-237
VIN:
to
2010
2016
LGH
2017
2022
LWN
2011
2016
LML, LGH
L5P
2017
2018
2020
2021
2022
2022
from
to
Engine:
from
Transmission:
LM2
Sierra2500/3500
2019
2022
L5P
Sierra Limited
2019
2019
L5P
Yukon Models
2020
2022
LM2
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.
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.
4373640
Bulletin No.: 19-NA-237
January, 2022
Page 3
Diesel Exhaust Fluid (DEF) mixed with Brake Fluid.
4373644
4373641
Diesel Exhaust Fluid (DEF) mixed with Engine Oil.
Diesel Exhaust Fluid (DEF) mixed with Dexcool.
4373645
4373642
Diesel Exhaust Fluid (DEF) mixed with Diesel Fuel.
Diesel Exhaust Fluid (DEF) mixed with Power Steering
Fluid.
Page 4
January, 2022
Bulletin No.: 19-NA-237
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.
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.
4373647
Version
3
Modified
Released October 17, 2019
Revised October 27, 2020 - Added 2021 Model Year.
Revised January 10, 2022 - Added 2022 Model Year.
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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