19-NA-237

Bulletin No.:
Service Bulletin
Date:
19-NA-237
March, 2023
INFORMATION
Subject:
Diagnostic Tip - Diesel Exhaust Fluid System Contamination
This bulletin replaces PIP5370D. Please discard PIP5370D.
Brand:
Cadillac
Model:
VIN:
from
to
Engine:
from
to
Escalade Models
2021
2023
LM2
XT4
2020
2023
LSQ
2014
2015
LUZ
Cruze
2017
2019
LH7
Colorado
2016
2022
LWN
Equinox
2018
2019
LH7
2010
2016
LGH
2017
2022
LWN
2011
2016
LML
Express
Silverado
Chevrolet
Model Year:
2017
2018
2020
2021
2022
2022
Silverado 1500
2023
2023
LZ0
Silverado 1500
Silverado 1500 LTD (RPO J21,
VIN Digit 5 = W / Y)
Silverado 1500 New
(RPO J22, VIN Digit 5 = A / D)
—
—
L5P
LM2
Silverado 2500/3500
2019
2024
L5P
Silverado 4500HD, 5500HD and
6500HD
2019
2023
L5D
Suburban
2021
2023
LM2
Tahoe
2021
2023
LM2
Copyright 2023 General Motors LLC. All Rights Reserved.
Transmission:
—
Page 2
March, 2023
Brand:
Model Year:
Model:
Savana
Sierra
VIN:
from
to
Engine:
from
to
2010
2016
LGH
2017
2022
LWN
2011
2016
LML, LGH
L5P
2017
2018
2020
2021
2022
2022
Sierra 1500
2023
2023
Sierra 2500/3500
2019
2024
L5P
Yukon Models
2021
2023
LM2
Sierra 1500
GMC
Bulletin No.: 19-NA-237
Sierra 1500 Limited (RPO J21,
VIN Digit 5 = 8 / 9)
Sierra 1500 New (RPO J22, VIN
Digit 5 = H / U)
—
—
Transmission:
LM2
—
LZ0
Involved Region or Country
United States, Canada, Europe, Middle East, Israel, Palestine, GM Korea Company,
Thailand, Australia/New Zealand
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
Important: Service agents must comply with all
International, Federal, State, Provincial, and/or
Local laws applicable to the activities it performs
under this bulletin, including but not limited to
handling, deploying, preparing, classifying,
packaging, marking, labeling, and shipping
dangerous goods. In the event of a conflict between
the procedures set forth in this bulletin and the
laws that apply to your dealership, you must follow
those applicable laws.
Below are examples of DEF mixed with different
sources of contamination.
4373640
Diesel Exhaust Fluid (DEF) mixed with Brake Fluid.
Bulletin No.: 19-NA-237
March, 2023
Page 3
4373641
Diesel Exhaust Fluid (DEF) mixed with Dexcool.
4373644
Diesel Exhaust Fluid (DEF) mixed with Engine Oil.
4373642
Diesel Exhaust Fluid (DEF) mixed with Diesel Fuel.
4373645
Diesel Exhaust Fluid (DEF) mixed with Power Steering
Fluid.
Page 4
March, 2023
Bulletin No.: 19-NA-237
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
Diesel Exhaust Fluid (DEF) mixed with Windshield
Washer Fluid.
Version
5
Modified
Released October 17, 2019
Revised October 27, 2020 – Added 2021 Model Year.
Revised January 10, 2022 – Added 2022 Model Year.
Revised September 12, 2022 – Added 2023 Model Year and Important statement under
Information.
Revised March 16, 2023 – Added the 2024 Model Year for the Silverado/Sierra 2500/
3500 trucks, XT4 with LSQ model and updated the Involved Region or Country 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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