23-NA-185

Bulletin No.:
Service Bulletin
Date:
23-NA-185
January, 2024
INFORMATION
Subject:
Information on Helping Reduce Customer Concern Not Duplicated (CCND) on Transfer
Cases - Service 4WD on the Drivers Instrument Center (DIC), Intermittent Failures,
Noise Concerns, Drivers Driveline/Steering Vibration/Shudder, Intermittent DTC’s/
Malfunction Indicator Lamp (MIL) Illuminated, Engagement/Disengagement/Ratcheting
Concerns
Brand:
Model:
Cadillac
Escalade
2020
2023
Colorado
2023
2024
2019
2019
Silverado 1500
(New Model)
2019
2021
2022
2022
Silverado 1500 New
(RPO J22, 12th VIN
Digit = 5 or greater)
Silverado 1500
2023
Silverado 2500HD/
3500HD
2020
Suburban
Tahoe
GMC
VIN:
to
Silverado LD
Silverado 1500 LTD
(RPO J21, 12th VIN
Digit = 4 or less)
Chevrolet
Model Year:
from
2020
2024
2023
Canyon
2023
2024
Sierra Limited
2019
2019
Sierra 1500 (New
Model)
2019
2021
2022
2022
Sierra 1500 Limited
(RPO J21, 12th VIN
Digit = 4 or less)
Sierra 1500 New
(RPO J22, 12th VIN
Digit = 5 or greater)
Sierra 1500
2023
Sierra 2500/HD/
3500HD
2020
Yukon Models
2020
Copyright 2024 General Motors LLC. All Rights Reserved.
2024
2023
from
to
Engine:
Transmission:
Page 2
January, 2024
Bulletin No.: 23-NA-185
Involved Region or Country
North America, Middle East, Israel, Palestine, Chile, Paraguay, Uruguay, Peru, Japan,
Thailand, Australia, New Zealand, Uzbekistan, Russia, Columbia, Ecuador, GM Korea
Company, S. Korea, and Europe.
Additional RPO
NP0 (TRANSFER CASE-ACTIVE, SINGLE SPEED, SWITCH ACTIVATED, ALUM)
NQF (TRANSFER CASE-ELECTRIC SHIFT CONT, TWO SPEED, ALUM)
NQG (TRANSFER CASE-MANUAL SHIFT CONT, TWO SPEED, ALUM)
NQH (TRANSFER CASE-ACTIVE, TWO SPEED, SWITCH ACTIVATED, ALUM)
Condition
Some customers may comment on one or more of the following conditions:
• Service 4WD on the DIC
• MIL illuminated
• Intermittent Failures
• Noise Concerns
• Drivers Driveline/Steering Vibration/Shudder
• Intermittent DTC’s
• Engagement/Disengagement/Ratcheting Concerns
Cause
This condition may be caused by several possible causes.
Information
The flow chart below is intended to help better diagnose the vehicle and eliminate the
chances of another visit by the customer.
Diagnosing CCND Issues
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.
NO, move onto 6
6. Perform a
thorough visual
inspection of the
area of the
vehicle related to
the customer
concern.
7. Could the issue
be intermittent?
Yes
Refer to SI for the
concern.
Yes
Refer TSB 19NA-136.
NO, move onto 3
Yes
Refer to FourWheel Drive in
Owner’s Manual.
NO, move onto 4
4. Are there any
current DTCs on
the scan tool?
Yes
Refer to SI for the
concern DTC.
NO, move onto 5
5. Refer to scan
tool for DTC
history display.
Refer to TSB 22NA-187.
Yes
8. Verify that the
TCCM has the
latest calibration
through SPS2.
No
Follow instructions
on SPS2
programming tool.
Additional information for steps above:
NO, move onto 2
3. Is the issue
present only on
4HI or 4LO (if
equipped)?
Yes
NO, move onto 8
Diagnosing CCND Issues
2. Is the problem
noise related?
Replace any
damaged part.
NO, move onto 7
Service Procedure
1. Can you
duplicate the
complaint?
Yes
Use Freeze Frame
Failure Records
on the scan tool to
find DTCs that are
stored in the
history of the
module.
1. The issue reported by the customer might/might
not be duplicated by the technician during the visit.
2. Some issues in the transfer case might be able to
be duplicated and can also be eliminated with the
drain and fill referred on the TSB. Refer to the
Symptoms – Transfer Case document in SI for
more information on diagnosing noise related
concerns.
3. The condition could be normal. Refer to the
Owner’s Manual, Driving and Operating, Drive
Systems, Four-Wheel Drive. When the front
driveline is engaged/functioning, additional
components start moving and that can increase the
noise levels heard in the cabin of the vehicle. If
possible, compare to a similarly equipped with
similar mileage known good vehicle.
4. Some issues might be related to DTCs that trigger
the Service 4WD warning on the dashboard. If that
is the case, review the specific SI information
pertaining to the DTC to resolve the issue.
Bulletin No.: 23-NA-185
January, 2024
Page 3
5. Check scan tool for DTCs that could have cleared
after 40 ignition cycles. This could have caused the
customer’s concern if the service 4WD light is not
on anymore. The Freeze Frame Failure Records
screen can be found navigating through the
following:
⇒ Module diagnostics
⇒ TCCM
⇒ Diagnostic Trouble Codes
⇒ Freeze Frame Failure Records
– In most of the cases, DTC’s starting with a “C”
are the cause of a Service 4WD light on the
cluster/dashboard.
6. Check the surroundings of the transfer case for
damage in the components that interact with it,
check for cut wires, confirm proper terminal tension
in the transfer case terminal connector.
7. In some instances, the issue could be related to
intermittences coming from the harness. Follow the
TSB for more detail on components to check.
8. Make sure the vehicle has the latest software/
calibration installed in the TCCM. If not, reflash it
with the latest version available following the SPS2
tool directions
Warranty Information
Note: Only select the labor operation that coincides
with the repair performed.
Note: If no problem was found after running the
diagnostics listed in the bulletin, use 0542709 Transfer
Case - Customer Concern Not Duplicated (CCND)
for vehicles that had an electrical repair use:
Labor Operation
Description
Labor Time
5430902
Wire-to-Wire Repair
5430840
Terminal Replacement
Use the Published Labor
Operations Time
Version
2
Modified
Released October 24, 2023
Revised January 04, 2024 - Added Colorado and Canyon to Models 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.
WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION
Bulletin No.: 23-NA-185
January, 2024
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