Subject: Loud Noise Inside Cabin at 1200-2500 RPMs
This Service Bulletin replaces PIC6520. Please discard PIC6520.

ModBrand:
el:

Model
Year:
from

Cadillac

XT4

to

VIN:

Engine:

Transmission:

from ot

2024 2024

Involved Region or Country

North America

Additional Options (RPOs)

Condition

Some customers may comment on a loud noise inside the cabin at 1200–2500 RPMs.
Condition typically only occurs during one drive cycle and does not repeat on the next drive cycle if
vehicle has gone through an extended sleep cycle.
If customer shuts vehicle off and back on quickly without letting vehicle systems to fully sleep the issue
could occur on the following drive cycle.
Note: Verify that the loud noise in the cabin is coming from the ANC microphone by rolling down the
window while driving when noise occurs. The noise should immediately stop.

Cause

The cause of the condition may be that an active noise cancellation microphone is projecting engine
noise into the cabin.
Update Vehicle Communication Unit (VCU) software.

Correction

Important: VCU software R4.5.1 was released for service on December 14, 2023 that fully resolves
this issue. Vehicles that received a VCU software update prior to December 14, 2023 will require an
additional software update to correct this issue.

Service Procedure
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.
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.
• 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 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 12 V 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.

• Clear DTCs after programming is complete. Clearing powertrain DTCs will set the Inspection/Maintenance (I/M)
system status indicators to NO.
Important: The service technician always needs to verify that the VIN displayed in the TLC left side drop down menu
and the top center window match the VIN plate of the vehicle to be programmed prior to using Service Programming
System 2 (SPS2) for programming or reprogramming a module.
• For the TLC application, service technicians need to always ensure that the power mode (ignition) is “ON” before
reading the VIN from the vehicle’s VIN master module and that they do not select a VIN that is already in the TLC
application memory from a previous vehicle.
• If the VIN that shows up in the TLC top center window after correctly reading the VIN from the vehicle does not
match the VIN plate of the vehicle, manually type in the VIN characters from the vehicle VIN plate into the TLC top
center window and use these for programming or reprogramming the subject module with the correct vehicle VIN
and software and/or calibrations.
• The Engine Control Module (ECM) is the master module (for VIP vehicles) that TLC reads to determine the VIN of
the vehicle. If the VIN read from the vehicle by TLC does not match the VIN plate of the vehicle, the ECM also needs
to be reprogrammed with the correct VIN, software and calibrations that match the vehicle’s VIN plate.
• The Body Control Module (BCM) is the master module (for GEM vehicles) that TLC reads to determine the VIN of
the vehicle. If the VIN read from the vehicle by TLC does not match the VIN plate of the vehicle, the BCM also needs
to be reprogrammed with the correct VIN, software and calibrations that match the vehicle’s VIN plate.
Caution: Be sure the VIN selected in the drop down menu (1) is the same as the vehicle connected (2) before beginning
programming.

5743643

Important: If the vehicle VIN DOES NOT match, the message below will be shown

5877000

5644477

Important: Techline Connect screens shown above.
Important: If the same calibration/software warning is noted on the TLC 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 section of the bulletin.

1. Reprogram the VCU Module. Refer to A11 Radio: Programming and Setup .

5644478

Note: The screenshot above is 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
Warranty Claim Code (WCC) screen shown above on the job card. Refer to callout 1 above for the location of the
WCC on the screen.
2. Record SPS Warranty Claim Code on 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

*2889898

Radio Reprogramming for Vehicle Cabin
Noise with SPS

0.3 hr

*This is a unique Labor Operation for Bulletin use only.

Labor Operation

Description

Labor Time

Important: **To avoid warranty transaction rejections, carefully read and follow the instructions below:

6125814

• The Warranty Claim Code must be accurately entered in the “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
“Warranty Claim Code” field of the transaction, otherwise the transaction will reject. It is best practice to enter the
FINAL code provided by SPS2.

Warranty Claim Code Information Retrieval

6125774

If the Warranty Claim Code was not recorded on the Job Card, the code can be retrieved in the SPS2 system as follows:
1.
2.
3.
4.

Open TLC on the computer used to program the vehicle.
Select and start SPS2.
Select Settings (1).
Select the Warranty Claim Code tab (2).

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 October 23, 2023
Revised December 18, 2023 - Added Important statement to Correction Section.