Bulletin No.:

Service Bulletin

Date:

20-NA-174
September, 2020

TECHNICAL
Subject:

Malfunction Indicator Lamp (MIL) Illuminated with DTC P037C

Brand:

Model:

Cadillac

CT4

Model Year:

VIN:

from

to

from

to

2020

2020

—

—

Engine:

Transmission:

2.7L
Turbo (L3B)

All

Involved Region or Country

North America, Middle East

Condition

Some customers may comment on an MIL light illuminated with DTC P037C Cold Start
Camshaft Profile System Performance set current or in history.

Cause

The cause of the condition may be a software anomaly.

Correction

Reprogram the Engine Control Module (ECM) with the most current level of 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.
Ensure the ignition is turned OFF, load on the
vehicle’s battery such as; interior lights, exterior
lights (including daytime running lights), HVAC,
etc. may affect the download process.
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

September, 2020

Bulletin No.: 20-NA-174

5644477

5431207

Bulletin No.: 20-NA-174

September, 2020

Page 3

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 Engine Control Module. Refer to
K20 Engine Control Module: Programming and
Setup in SI.

5644478

Page 4

September, 2020

Bulletin No.: 20-NA-174

5431209

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
Important: Warranty coverage code E (Base
Emission) and E2 (8 years/80,000 miles (U.S.) or 8
years/130,000 km (Canada) applies for this module
programming event.
For vehicles repaired under warranty, use:
Labor
Operation

Description

2810075

Engine Control Module
Reprogramming with SPS

Labor Time

Use
Published
Labor
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/SPS2.

Bulletin No.: 20-NA-174

September, 2020

Page 5

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

1

Modified

Released August 28, 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.

WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION