21NA244

Bulletin No.:
Service Bulletin
Date:
21-NA-244
November, 2021
TECHNICAL
Subject:
No Fob Detected Message on Driver Information Center (DIC) with No Crank/No Start
This bulletin replaces PIT5841A. Please discard all copies of PIT5841A.
Brand:
Model:
Buick
Envision
Cadillac
Chevrolet
GMC
Model Year:
from
VIN:
to
Engine:
Transmission:
All
All
All
All
All
All
All
All
All
All
All
All
All
All
All
from
to
2021
All
CT4
2020
CT5
2020
Escalade
2021
2021
Corvette
2021
All
All
All
All
Suburban
2021
All
All
All
All
Tahoe
2021
All
All
All
All
Yukon
2021
All
All
All
All
Involved Region or Country
North America
Condition
Some customers may comment on a No Crank / No Start condition with a "No Fob
Detected" message on the DIC. The Remote Keyless Entry (RKE) key fob will also not be
detected in the backup pocket. Key fobs will work actively (button press) but not
passively. There are no current passive antenna or Immobilizer DTCs set in the Body
Control Module (BCM). The vehicle will have battery power (battery state of charge above
12 volts) but will not power mode to the RUN or Accessory position, which will not allow
the transmission to be shifted from Park. Also, the parking brake may be engaged and
not be able to be released.
Cause
It has been determined that an internal BCM fault causes the fobs to not be recognized
and loss of immobilizer.
Correction
If you encounter a vehicle with the above concern,
perform the following steps:
1. Verify that the Active RKE functions are working for
all transmitters (example: Locking/Unlocking/Horn/
Trunk and Remote Start).
2. Verify ALL Passive RKE functions are inoperative
for both transmitters.
3. Verify Low Frequency (LF) “Passive” Antennas
ARE NOT transmitting by using the Service Tool
EL-52545.
4. Verify that the Transmitters ARE NOT responding
to the Passive Challenge with the Service Tool
EL-52545, without pressing any buttons on the
transmitters.
Copyright 2021 General Motors LLC. All Rights Reserved.
5. Is the vehicle's battery above 12V?
6. There should be no current antenna or immobilizer
DTCs set in the BCM.
7. With both transmitters outside of the vehicle,
attempt to change the power mode by pressing the
start stop switch once every 3 seconds, 5 times.
Check for DTCs in the BCM. There should be no
current antenna or immobilizer DTCs set after
performing this step.
If questions 1-7 can all be answered as “YES”, replace
the BCM.
Refer to Service Information / Keyless Entry System
Malfunction (Example Document ID# 5606149) for
additional diagnostic procedures.
Page 2
November, 2021
Bulletin No.: 21-NA-244
Note: It may be possible to recover the vehicle from
this condition by performing a battery disconnect /
reset, allowing the vehicle's modules to completely
power down. If the vehicle cannot be recovered and
must be towed, ensure proper towing procedures are
followed including the use of wheel dollies and flatbed
towing (Reference SI Document ID# 5500849).
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
2887308*
Diagnose Inoperative Key
Fobs, Replace BCM, and
Program BCM
1.4 hrs
*This is a unique Labor Operation for bulletin use only.
Version
1
Modified
Released November 04, 2021
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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