NHTSA ID Number: 11033753
Manufacturer Communication Number: PIT6477C
TSB/Document Date: 2026-06-08
Summary
This preliminary PI was created to advise techniians in the field that they will not be able to perform a GDS automated bleed with the scan tool dues to a issue with the software in the scan tool
Bulletin No.: PIT6477C
Service Bulletin
Date: June, 2026
PRELIMINARY INFORMATION
Subject:
Brand:
Unable to Perform GDS2 Automated Bleed After Master Cylinder Replacement
Model:
Model Year:
from
VIN:
to
from
Engine:
to
Escalade
2021-2026
ALL
ALL
ALL
ALL
Escalade
ESV
2021-2026
ALL
ALL
ALL
ALL
ESCALADE
IQ
2025-2026
ALL
ALL
ALL
ALL
ESCALADE
IQL
2026
ALL
ALL
ALL
ALL
Silverado
1500
2022-2026
ALL
ALL
ALL
ALL
Silverado EV
2024-2026
ALL
ALL
ALL
ALL
Suburban
2021-2026
ALL
ALL
ALL
ALL
Tahoe
2021-2026
ALL
ALL
ALL
ALL
ALL
ALL
ALL
ALL
HUMMEV EV 2024-2026
SUV
ALL
ALL
ALL
ALL
SIerra 1500
2022-2026
ALL
ALL
ALL
ALL
Sierra EV
2024-2026
ALL
ALL
ALL
ALL
Yukon
2021-2026
ALL
ALL
ALL
ALL
Yukon XL
2021-2026
ALL
ALL
ALL
ALL
Involved Region or Country
North America
Condition
Some Technicians may notice that they get an error screen when trying to perform the
automated bleed after master cylinder replacement, (See Error Screen Below).
Cause
Software Anomaly with GDS2 Software.
Copyright 2026 General Motors
. All Rights Reserved.
Page 2
June, 2026
Bulletin No.: PIT6477C
7058016
Correction
An updated version of GDS2 has been released to address this issue. Please launch Techline Connect (TLC) and
verify that GDS2 is updated to GM Global version v2026.05.31 or later.
When performing the GDS2 Auto Brake Bleed procedure, you will now see two options: “Automated Brake Bleed”
and “Modified Automated Brake Bleed.”
Begin by selecting “Automated Brake Bleed.” If the procedure completes successfully, no further action is required.
If the “Automated Brake Bleed” procedure does not complete successfully, proceed with “Modified Automated Brake
Bleed,” which incorporates the updated fix.
Version
4
Modified
01/26/2026- Created on
01/30/2026- Updated to add additional note to correction field
02/17/2026-Updated to add the repair procedure
06/05/2026-Updated to add models
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: PIT6477C
Replacement Service Bulletin Number:
MFR Communication Date: 2026-06-05
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: UNKNOWN OR OTHER
MFR Component System:
MFR Component Subsystem:
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