Service Bulletin

Bulletin No.:

21-NA-111

Date:

May, 2021

TECHNICAL
Subject:

Check Engine Light Illuminated, No Start/ No Propulsion, DTC P0A0C
This bulletin replaces PIC6211A. Please discard PIC6211A.

Brand:

Model:

Buick
Chevrolet

Model Year:

VIN:

from

to

Velite

2017

2018

Volt

2016

2018

from

to

—

—

Engine:

Transmission:

—

5ET50

LKA

MKV

Involved Region or Country

North America, China

Additional Options (RPOs)

L3A or MKA

Condition

Some customers may comment on one or all of the following concerns:
• No Start
• Loss of propulsion while driving
• Check Engine Lamp illuminated

Cause

The cause of the condition may be software anomalies.
Technicians may find DTC P0A0C set current or in recent history.

Correction

Reprogram the Hybrid Powertrain Control Module 2 with the latest calibration.
The HPCM2 will then ignore the interlock circuit and P0A0C will no longer be a valid DTC
for the vehicle. Circuits 5087 & 5088 are no longer present in A28 Battery Disconnect
Units.

Service Procedure
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.
Note: Carefully read and follow the instructions below.
•

•

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

Copyright 2021 General Motors LLC. All Rights Reserved.

charged 12V 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.
Caution: Be sure the VIN selected in the drop down
menu (1) is the same as the vehicle connected (2)
before beginning programming.

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Important: Techline Connect and TIS2WEB screens
shown above.
Important: If the same calibration/software warning is
noted on the TLC or SPS 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 Information section of this bulletin.
Important: When programming a module in GM’s new
Vehicle Intelligence Platform, or VIP, the power mode
(ignition) needs to be off or errors may occur. This
involves the 2020 Chevrolet Corvette, Cadillac CT5 and
CT4, as well as the upcoming full-size Chevrolet, GMC,

Cadillac SUVs and Buick Envision. Serial Data
Message Authentication also needs to have the
ignition off.
1. Reprogram the Hybrid Powertrain Control Module
2. Refer to K114B Hybrid/EV Powertrain Control
Module 2: Programming and Setup in SI.

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Note: The screenshots above are 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 SPS Warranty Claim Code (WCC) screen shown
above on the job card. Refer to callout 1 above for the
location of the WCC on the SPS screen.
2. Record the SPS Warranty Claim Code on the job
card for warranty transaction submission.

Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation

Description

Labor Time

Use
Published
Labor
2810265*
Operation
Time
Important: *To avoid warranty transaction rejections,
carefully read and follow the instructions below:
• The Warranty Claim Code must be accurately entered
in the “SPS 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 “SPS Warranty Claim Code” field of the
transaction, otherwise the transaction will reject. It is
best practice to enter the FINAL code provided by
SPS/SPS2.
Hybrid Powertrain Control
Module 2 Reprogramming
with SPS

Warranty Claim Code Information Retrieval
If the SPS Warranty Claim Code was not recorded on
the Job Card, the code can be retrieved in the SPS
system as follows:
1. Open TLC/TIS on the computer used to program
the vehicle.
2. Select and start SPS/SPS2.
3. Select Settings.
4. Select the Warranty Claim Code tab.
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

1

Modified

Released May 06, 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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