Service Bulletin

Bulletin No.:

20-NA-099

Date:

May, 2020

TECHNICAL
Subject:

Park Assist Not Available to Turn On or Off and Possible Driver Information Center
(DIC) Illuminated with DTC U0159 Set

Brand:

Model:

Cadillac

CT6

Model Year:

VIN:

from

to

2019

2020

from

to

Engine:

Transmission:

All

All

Involved Region or Country

United States, Canada, Europe, Russia, Middle East, Israel, Japan, Cadillac Korea
(South Korea)

Condition

Some customers may comment that they are unable to turn Park Assist on or off and may
also have a message on the DIC.

Cause

The cause of the condition may be a software anomaly that may result in a logic lock and
prevent the feature from functioning.
The technician may also find DTC U0159 stored.

Correction

Reprogram the Park Assist Module with the latest released software.

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.

•

•

Copyright 2020 General Motors LLC. All Rights Reserved.

Stable battery voltage is critical during
programming. Any fluctuation, spiking, over
voltage or loss of voltage will interrupt
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.
Turn OFF or disable systems that may put a load
on the vehicles battery such as; interior lights,
exterior lights (including daytime running lights),
HVAC, radio, etc.
Clear DTCs after programming is complete.
Clearing powertrain DTCs will set the Inspection/
Maintenance (I/M) system status indicators to NO.

Page 2

May, 2020

Bulletin No.: 20-NA-099

5431207

Important: TIS2WEB screen shown. Techline Connect
screen is similar and will be included soon.
Important: If the Same Calibration/Software Warning
is noted on the SPS 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.
1. Reprogram the Parking Assist Control Module.
Refer to K182 Parking Assist Control Module:
Programming and Setup in SI. Modify as required
(e.g., select x module from the controller screen).
Then provide step-by-step instructions or refer to
SI procedure.

Bulletin No.: 20-NA-099

May, 2020

Page 3

5431209

Important: TIS2WEB screen shown. Techline Connect
screen is similar and will be included soon.
Important: To avoid warranty transaction rejections,
you MUST record the warranty claim code provided on
the SPS Warranty Claim Code (WCC) screen 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 warranty, use:
Labor
Operation

Description

Labor Time

Use
Published
Labor
2810375*
Operation
Time
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.
Parking Assist Control
Module Reprogramming
with SPS

Page 4

May, 2020

Bulletin No.: 20-NA-099

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 TIS on the computer used to program the
vehicle.
2. Select and start SPS.
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

1

Modified

Released May 04, 2020

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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