20NA178

Service Bulletin
Bulletin No.:
20-NA-178
Date:
May, 2021
TECHNICAL
Subject:
Brand:
Cadillac
Chevrolet
GMC
Service Driver Assist and/or Take Steering Messages on Start-up, Advanced Driver
Assist Systems (ADAS) Features Not Available
Model:
CT4
CT5
Suburban
Tahoe
Yukon
Yukon XL
Model Year:
VIN:
from
to
2020
2021
2021
2021
2021
2021
from
to
—
—
Engine:
Transmission:
All
All
Involved Region or Country
North America, Colombia, Israel, Middle East, Cadillac Korea (South Korea), China
Additional Options (RPOs)
Equipped with RPO UGN
Condition
Some customers may comment on a Service Driver Assist message and Take Steering
message on start-up, Advanced Driver Assist Systems (ADAS) features are not available
during this time.
During this condition, the Image Processing Module becomes stuck in a continuous reset
state on power up, causing it to be inoperable and stop all communication.
Cause
The cause of the condition may be a software anomaly.
Correction
Action to be performed by dealer to confirm this service bulletin is applicable for the
above customer concern:
1. Verify the Image Processing Module is not communicating on all three CAN busses
(CAN1, CAN2, CAN8).
2. Verify for presence of 3 loss of Communication DTCs (U1614, U1615 , U1616) set
by other modules against the Image Processing Unit.
3. If step (1) and (2) are both true, the issue may be resolved by resetting the power.
Either by disconnecting vehicle battery or disconnecting the fuse to the controller for
1 minute. The module should start communication once power is connected.
4. Update the K124 Image Processing Module with latest software and calibrations.
Service Procedure
Caution: Before downloading the update files, be sure
the computer is connected to the internet through a
network cable (hardwired). DO NOT DOWNLOAD or
install the files wirelessly. If there is an interruption
during programming, programming failure or control
module damage may occur.
Note: Carefully read and follow the instructions below.
•
•
Ensure the programming tool is equipped with the
latest software and is securely connected to the
data link connector. If there is an interruption
during programming, programming failure or
control module damage may occur.
Stable battery voltage is critical during
programming. Any fluctuation, spiking, over
voltage or loss of voltage will interrupt
Copyright 2021 General Motors LLC. All Rights Reserved.
•
•
•
programming. Install a GM Authorized
Programming Support Tool to maintain system
voltage. Refer to www.gmdesolutions.com for
further information. If not available, connect a fully
charged 12V jumper or booster pack disconnected
from the AC voltage supply. DO NOT connect a
battery charger.
Follow the on-screen prompts regarding ignition
power mode, but ensure that anything that drains
excessive power (exterior lights, HVAC blower
motor, etc) is off.
Please verify that the radio time and date are set
correctly before inserting USB drive into vehicle
for programming, otherwise an error will result.
Clear DTCs after programming is complete.
Clearing powertrain DTCs will set the Inspection/
Maintenance (I/M) system status indicators to NO.
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Bulletin No.: 20-NA-178
Caution: Be sure the VIN selected in the drop down
menu (1) is the same as the vehicle connected (2)
before beginning programming.
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Important: Techline Connect and TIS2WEB screens
shown above.
Important: If the same calibration/software warning is
noted on the TLC or SPS Summary screen, select OK
and follow screen instructions. After a successful
programming event, the WCC is located in the Service
Programming System dialogue box of the SPS
Summary screen. No further action is required. Refer to
the Warranty Information section of this bulletin.
Important: When programming a module in GM’s new
Vehicle Intelligence Platform, or VIP, the power mode
(ignition) needs to be off or errors may occur. This
involves the 2020 Chevrolet Corvette, Cadillac CT5 and
CT4, as well as the upcoming full-size Chevrolet, GMC,
Cadillac SUVs and Buick Envision. Serial Data
Message Authentication also needs to have the
ignition off.
1. Reprogram the Image Processing Module. Refer to
K124 Image Processing Module: Programming
and Setup in SI.
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Note: The screenshots above are an example of
module programming and may not be indicative of the
specific module that is being programmed. Module
selection and VIN information have been blacked out.
Important: To avoid warranty transaction rejections,
you MUST record the warranty claim code provided on
the SPS Warranty Claim Code (WCC) screen shown
above on the job card. Refer to callout 1 above for the
location of the WCC on the SPS screen.
2. Record the SPS Warranty Claim Code on the job
card for warranty transaction submission.
Warranty Information
For vehicles repaired under the Bumper-to-Bumper
coverage (Canada Base Warranty coverage), use the
following Labor Operation. Reference the Applicable
Warranties section of Investigate Vehicle History (IVH)
for coverage information.
Labor
Operation
Description
Labor Time
2886998*
Reprogram Image
processing Unit for
continuous reset with SPS
0.3 hr
*This is a unique Labor Operation for bulletin use only.
Important: To avoid warranty transaction rejections,
carefully read and follow the instructions below:
• The SPS Warranty Claim Code must be accurately
entered in the “SPS Warranty Claim Code” field of the
transaction.
• When more than one Warranty Claim Code is
generated for a programming event, it is required to
document all Warranty Claim Codes in the “Correction”
field on the job card. Dealers must also enter one of the
codes in the “SPS Warranty Claim Code” field of the
transaction, otherwise the transaction will reject. It is
best practice to enter the FINAL code provided by
SPS/SPS2.
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Bulletin No.: 20-NA-178
Warranty Claim Code Information Retrieval
If the SPS Warranty Claim Code was not recorded on
the Job Card, the code can be retrieved in the SPS
system as follows:
1. Open TLC/TIS on the computer used to program
the vehicle.
2. Select and start SPS/SPS2.
3. Select Settings.
4. Select the Warranty Claim Code tab.
The VIN, Warranty Claim Code and Date/Time will be
listed on a roster of recent programming events. If the
code is retrievable, dealers should resubmit the
transaction making sure to include the code in the SPS
Warranty Claim Code field.
Version
2
Modified
Released September 09, 2020
May 14, 2021 – Added Additional Option RPO UGN, removed Europe from Involved
Region or Country section and updated programming procedure.
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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