NHTSA ID Number: 10199263
Manufacturer Communication Number: 21NA088
TSB/Document Date: 2021-07-19
Summary
This service bulletin provides repair information to correct a customer concern of a Check Engine Light Displayed on Driver Information Center (DIC), Engine Cooling Fan Windmilling, DTC P0494 Set.
Service Bulletin
Bulletin No.:
21-NA-088
Date:
May, 2021
TECHNICAL
Subject:
Check Engine Light Displayed on Driver Information Center (DIC), Engine Cooling Fan
Windmilling, DTC P0494 Set
Brand:
Model:
Model Year:
VIN:
from
to
Enclave
2021
2021
3.6L (LFY)
XT5
2020
2021
3.6L (LGX)
XT6
2021
2021
Blazer
2020
2021
—
to
Engine:
from
—
3.6L (LGX)
3.6L (LGX)
Traverse
2021
2021
3.6L (LFY)
Acadia
2020
2021
3.6L (LGX)
—
Involved Region or Country
North America, Europe, Russia, Middle East, Israel, Palestine, Japan, Australia/New
Zealand
Condition
Some customers may comment on a Check Engine light displayed in the DIC and
experiencing no driving issues.
Cause
The cause of the condition may be ECM calibration timing causing the MIL to set during
"windmilling" of cooling fan, especially at restart during a stop/start event.
If this occurs on two consecutive ignition cycles, the technician may find DTC P0494 set
current or in recent history.
Correction
Reprogram the engine control module (ECM).
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.
• 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.
Caution: Be sure the VIN selected in the drop down
menu (1) is the same as the vehicle connected (2)
before beginning programming.
Page 2
May, 2021
Bulletin No.: 21-NA-088
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5644477
Bulletin No.: 21-NA-088
May, 2021
Page 3
5431207
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.
Page 4
May, 2021
Bulletin No.: 21-NA-088
5644478
5431209
Bulletin No.: 21-NA-088
May, 2021
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 Emission coverage,
use the following labor operation. Reference the
Applicable Warranties section of Investigate Vehicle
History (IVH) for coverage information.
Important: Warranty coverage code E2 applies for this
module programming event. ECM reprogramming is
covered for 8 years/80,000 miles (U.S.) or 8 years/
130,000 km (Canada).
Labor
Operation
2887228*
Description
Labor Time
ECM Reprogramming with
SPS for DTC P0494
0.3 hr
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.
*This is a unique Labor Operation for bulletin use only.
Important: To avoid warranty transaction rejections,
carefully read and follow the instructions below:
• The 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.
Version
2
Modified
Released April 09, 2021
May 03, 2021 – Added the 2021 Buick Enclave, Cadillac XT6 and Chevrolet Traverse
models and updated the Engine column in Models table.
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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TSB/Document ID: 21NA088
Replacement Service Bulletin Number:
MFR Communication Date: 2021-05-03
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE
MFR Component System:
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