23-NA-073

Bulletin No.:
Service Bulletin
Date:
23-NA-073
September, 2023
TECHNICAL
Subject:
Brand:
Evaporative DTCs P0442, P0446, P0455 or P0449, Caused by Dust Intrusion into the
Evaporative Canister and Canister Vent Solenoid
Model:
Model Year:
from
to
2019
2019
Silverado 1500
2020
2023
Silverado 1500 LTD
(RPO J21, VIN Digit
5 = W / Y)
2022
2022
Silverado 1500 New
(RPO J22, VIN Digit
5 = A / D)
2022
2022
Silverado
2500 HD/3500 HD
2020
2024
Sierra 1500
(New Model)
2019
2019
Silverado 1500
(New Model - 12th
VIN Digit = 7) - 4WD
VIN:
from
Engine:
Transmission:
All
All
to
Silverado 1500
(New Model)
Chevrolet
GMC
Sierra 1500
2020
2023
Sierra 1500 Limited
(RPO J21, VIN Digit
5 = 8 / 9)
2022
2022
Sierra 1500 New
(RPO J22, VIN Digit
5 = H / U)
2022
2022
Sierra
2500 HD/3500 HD
2020
2024
Involved Region or Country
United States, Canada, Middle East, Israel
Condition
Some customers, who operate their vehicles in extremely dusty environments, may
experience dust intrusion into the EVAP system that can plug the canister and canister
vent solenoid and set DTC’s P0442, P0446, P0455 or P0449.
Cause
The condition may be caused the by the normal use of these vehicles operating in severe
dusty environments.
Copyright 2023 General Motors LLC. All Rights Reserved.
Page 2
September, 2023
Bulletin No.: 23-NA-073
Important: This repair is a customer pay alteration. All repair, and payment
authorization must come from the customer.
6325318
Correction
Note: The retro-fit to add the filter is described in the Service Procedure below.
For the retro-fit, the filter assembly P/N (with the 3 parts shown above) will need to
be utilized along with a 3/4" to 5/8" hose connector that can be obtain for a local
parts store. If a vehicle has already undergone the retro-fit and the vehicle returns
after a period of time with the Condition reappearing, the filter assembly can be
changed.
Note: The filter is meant to be maintenance item that should be checked
periodically to prevent the issue from reoccurring and the DTC from setting.
6327015
A filter may be installed between the EVAP canister and air inlet, to correct this Condition.
An example of the original, and the retro-fit, evaporative emission canister vent hose are
shown in the graphic above.
Bulletin No.: 23-NA-073
September, 2023
Page 3
Service Procedure
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.
1. Raise and support the vehicle. Refer to Lifting and
Jacking the Vehicle, in SI.
5041593
2. Remove the evaporative emission canister vent
hose (3). Refer to the appropriate Evaporative
Emission Canister Vent Hose Replacement (Filler
Pipe to Pipe), in SI.
Page 4
September, 2023
6325322
3. Cut the vent hose at the end of barbed fitting on the
pre filter (1).
Bulletin No.: 23-NA-073
6325326
5. Using the length of the original black corrugated
hose as a measurement, cut a length of 3/4 in.
diameter heater core hose the same appropriate
length.
6325324
4. Cut a 12 inch (30.5 cm) length of 3/4 in. diameter
heater core hose.
6325328
6. Secure the 12 inch (30.5 cm) length heater core
hose to the fitting on the pre filter (1), using a hose
clamp.
7. Secure the in-line filter (2) to the other end of 12”
(30.5 cm) length hose, using a hose clamp.
8. Secure the longer heater core hose to the fitting at
bottom of in-line filter (3), using a hose clamp.
9. Insert 5/8” male to male fitting (4) into heater core
hose on CVS side, using a hose clamp to secure.
Bulletin No.: 23-NA-073
September, 2023
Page 5
5041593
10. Connect 5/8” end of male fitting to the quick
connect on the CVS jumper line and install the
evaporative emission canister vent hose (3), to the
vehicle. Refer to the appropriate Evaporative
Emission Canister Vent Hose Replacement (Filler
Pipe to Pipe), in SI.
6325331
11. Using existing hose clips, and tie straps, clip new
hose at same location as previous line.
12. Lower the vehicle.
6325329
Page 6
September, 2023
Bulletin No.: 23-NA-073
Parts Information
Causal
Part
N/A
Description
Part
Number
Qty
FILTER ASMEVAP EMIS SYS
VAC LEAK PUMP
(ASSEMBLY)
86792068
1
FILTER ASMEVAP EMIS SYS
VAC LEAK PUMP
(FOAM FILTER)
86792069
1
Warranty Information
Important: This repair is not a warranty repair, but
a customer pay alteration. All repair, and payment
authorization must come from the customer.
Version
2
Modified
Released June 19, 2023.
Revised September 20, 2023 - Revised the Note Information to add a Hose Fitting in the
Correction 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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