21NA281

Bulletin No.:
Service Bulletin
Date:
21-NA-281
December, 2021
INFORMATION
Subject:
Diagnostic Tip – Transmission Neutral Service Mode
This bulletin replaces PIT5764B. Please discard PIT5764B.
Brand:
Cadillac
Model:
GMC
VIN:
to
from
to
Engine:
Transmission:
(Automatic)
CT4
RPO MQA
CT5
RPO MHS
Escalade
Models
Chevrolet
Model Year:
from
Suburban
2021
2022
—
—
—
RPOs
MHS, MQC
Tahoe
Yukon
Models
Involved Region or Country
North America
Condition
Certain service procedures or scenarios may require the transmission to be shifted into
Neutral so that the vehicle can be moved or to complete a repair.
Diagnostic Information
Vehicles equipped with an internal Electronic Transmission Range Select (ETRS) system
require hydraulic pressure to disengage the park mechanism. Please follow the
information listed below when trying to place the transmission into Neutral.
Correction
In cases where the engine can be started - Refer to the
Neutral Service Mode document in SI (example
Document ID # 5286309).
5641294
Copyright 2021 General Motors LLC. All Rights Reserved.
Page 2
December, 2021
Bulletin No.: 21-NA-281
Warning: The transmission will be placed in
N (Neutral) when the manual park release is pulled.
The vehicle can roll on you or others could be
injured. Ensure the vehicle is on level ground,
parking brake applied, and wheels blocked prior to
installation of the manual park release.
Warning: If fuel system is opened the fuel pump
should be disabled using the Fuel Pressure Relief,
Alternate Method by the removing the B+ fuel pump
control module fuse. Using the Fuel Pressure
Relief, Scan Tool Method will allow the fuel pump to
build pressure if the ignition is placed to run. See
Fuel Pressure Relief in Service Information for
complete instructions.
5710077
In cases of an ETRS system fault or a no start condition
- If the vehicle needs to be moved, it is recommended
to use wheel dollies, tire skates (example shown
above) or the NEW Manual Park Release tool
DT-52910 shown above (1). The manual park release
tool is available through the GM Special Service Tools
website. This new tool will allow the transmission to be
manually shifted to neutral, see example SI doc ID
5620825. The manual park release tool can be installed
to temporarily shift the vehicle into Neutral when the
engine is not running.
Caution: If the manual park release is pulled while the
vehicle is on or if the ignition is turned on while the
manual park release is pulled, the DIC will display a
message to service the transmission.
Caution: The latching mechanism in the manual park
release lever will release if the vehicle is started and
placed in Park. An attempt to override this function or
use of an un-approved tool may cause internal damage
to the transmission.
Version
1
Modified
Released November 30, 2021
Additional SI Keywords: tow, towing, haul, wrecker,
truck
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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