Bulletin No.:

Service Bulletin

Date:

21-NA-135
November, 2023

INFORMATION
Subject:

Information on Obtaining Techline Calibrations for Law Enforcement and Government
Vehicles to Disable or Enable Content
Model Year:

Brand:

Model:

Buick

GM Passenger Cars and Light
Duty Trucks
Excluding:
2022 Silverado 1500 New
(RPO J22, VIN Digit 5 = A / D)
2023 Silverado 1500
2022 Sierra 1500 New (RPO
J22, VIN Digit 5 = H / U)
2023 Sierra 1500

Cadillac
Chevrolet

GMC

VIN:

from

to

from

to

2019

2024

—

—

Engine:

Transmission:

—

—

Involved Region or Country

United States and Canada

Condition

The purpose of this bulletin is to inform dealership personnel about Law Enforcement and
Government vehicles that request to disable or enable content.

Cause

In some cases, it is not possible to disable/enable a feature. Contact the Techline
Customer Support Center (TCSC) to see if disabling/enabling the desired feature is
possible for the specific vehicle. The agency/requestor should be reminded that any
disabled features should be made fully operational or disclosed PRIOR to sale of the
vehicle.

Correction

Follow this process to obtain the calibration to make the above vehicle modifications. In
General Motors continuous effort to provide customer support, the following process is in
effect for those select governmental agencies that require and qualify for enabling/
disabling certain features.
Techline will provide the appropriate software change and instruct the technician how to
complete the reconfiguration.
Note: Check the Upfitter site for additional information for certain models/upfits.
Note: This is a customer pay repair.

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.
Important: In Canada, disabling DRL is prohibited
by Transport Canada.
1. ONLY the following governmental agencies qualify
for this disable/enable calibration request:
• City / State / Provincial Government
• Police / Sheriff Departments
Copyright 2023 General Motors LLC. All Rights Reserved.

• FBI
• CIA
• DEA
• RCMP
• Emergency Vehicles – if government owned
2. All requests are to be made through the Techline
Customer Support Center (TCSC) at
1-800-828-6860 English or 1-800-503-3222
French.
3. The dealership will be required to obtain a letter on
official agency letterhead requesting the disable/
enable. The letter should include the following:
• Acknowledgement that the agency owns the
vehicle
• The reason for the disable/enable
• Which features are to be disabled/enabled

Page 2

November, 2023

Bulletin No.: 21-NA-135

• Specific VIN(s) of the vehicle(s) that features
will be disabled/enabled
• Prior to any sale of the vehicle(s) listed above,
the agency will either (1) ensure that the [insert
feature(s) which has/have been requested for
disable/enable] system will be made fully
operational, or (2) disclose to the end customer
that such system is not operational. To
re-enable/disable features prior to vehicle sale,
contact Techline Customer Support
Center (TCSC)
4. The letter must be kept in the service history file at
the dealership, and a copy sent to TCSC before
the disable/enable procedures/calibrations will be
released. In most cases, the vehicle(s) will require
a software change, using a VCI number provided
by the TCSC.
This is a list of calibrations that are available:
6N5
BCV
BCN
9G8
UTQ
6J7
5J1
5J3
7Y6
UTJ
SK5
SK0
SK3
SK4
Engine time out disable (some models)
DRL disable
Version

5

Modified

Released June 10, 2021
Revised September 14, 2021 – Added the 2022 Model Year, a Note in the Correction
section and RPOs SK5, SK0, SK3, SK4.
Revised February 04, 2022 – Updated the Cause and #3 under Service Procedure.
Revised January 13, 2023 – Added excluded vehicles under Model section, the 2023
Model Year and the first Important statement under Service Procedure.
Revised November 16, 2023 – Added the 2024 Model Year.

Additional SI Keywords: Idle, 5W4, Police, 9C1,
Light, DRL

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