Bulletin No.:

Service Bulletin

Date:

18-NA-186
September, 2019

TECHNICAL
Subject:

Brand:

Loss of Propulsion or No Start with Malfunction Indicator Lamp Illuminated DTC P0A3F
or P1B03 Set

Model:

Model Year:

VIN:

from

to

Malibu E2

2016

2018

Volt D2

2016

2018

from

Chevrolet

to

—

Engine:

Transmission:

1.8L —
RPO LKN

5ET50 —
RPO MKE

1.5L —
RPO L3A

5ET50 —
RPO MKV

Involved Region or Country

North America, South Korea

Condition

Some customers may comment on a loss of propulsion and/or a no start with the
Malfunction Indicator Lamp (MIL) illuminated.

Cause

The internal transmission wiring harness may have backed out terminals, poor terminal
connections, corrosion, poor crimps, damaged terminals and/or high resistance in one or
more circuits. The Technician may find one or both of the following DTCs set in the T6
Power Inverter Module, also referred to as the Drive Motor Generator Power Inverter
Module:
• DTC P0A3F Drive Motor 1 Position Sensor Circuit
• DTC P1B03 Drive Motor 1 Position Sensor Circuit Tracking Lost

Correction

Review the Safety Information and perform the Service Procedure.

•

Safety Information
Important: Always perform the High Voltage
Disabling procedure prior to servicing any High
Voltage component or connection. Personal
Protection Equipment (PPE) and proper procedures
must be followed.
Danger: Ensure all High Voltage safety procedures
are followed. Failure to follow the procedure exactly
as written may result in serious injury or death.
Danger: Before working on any high voltage
system, be sure to wear the following Personal
Protection Equipment:
• Safety glasses with appropriate side shields when
within 50 feet (15.24 m) of the vehicle, either
indoors or outdoors.
• Certified and up-to-date Class “0” Insulation
gloves rated at 1000V with leather protectors.

Copyright 2019 General Motors LLC. All Rights Reserved.

Visually and functionally inspect the gloves
before use.
• Wear the Insulation gloves at all times when
working with the high voltage battery assembly,
whether the system is energized or not.
The High Voltage Disabling procedure only
de-energizes the high voltage circuits and
components outside of the Hybrid/EV battery pack.
Dangerous voltage levels always exist within the
Hybrid/EV battery pack.
The technician must verify that the high voltage
disabling procedure was successful by measuring
the applicable connectors for a safe voltage level
with a DMM.

Page 2

September, 2019

Service Procedure

Bulletin No.: 18-NA-186

2. Is DTC P0A3F or P1B03 Set?
⇒ If DTC P0A3F or P1B03 are Set, go to Step 3.
Continue even if the DTCs are Set as “Current”
or Set as “History”.
⇒ If the vehicle is setting additional faults for both
Drive Motor 1 Position Sensor Circuits and
Drive Motor 2 Position Sensor Circuits
simultaneously, or several additional DTCs are
set, contact GM Technical Assistance Center
(TAC) for diagnostic help before proceeding.
3. Disable the High Voltage. Refer to High Voltage
Disabling in SI.
4. Verify the date code on the replacement harness is
after 04/07/2018 prior to installation.
5. Replace the transmission wiring harness with Part
Number 24285319 HARNESS, A/TRNS WRG
CONT VALVE SOL. Refer to Automatic
Transmission Wiring Harness Replacement
in SI.
6. Perform the Diagnostic Repair Verification. Refer
to Diagnostic Repair Verification in SI.

Overview

Additional Keywords
5051615

The Drive Motor Power Inverter Module is an assembly
which contains two motor control modules and the
Hybrid/EV Powertrain Control Module 1. The drive
motor position sensor is monitored by its respective
motor control module.
The motor control module monitors the angular
position, speed and direction of the drive motor rotor
based upon the signals of the resolver-type position
sensor. The drive motor position sensor circuits operate
at very low current. These circuits are susceptible to
moisture intrusion, backed out terminal(s) (shown),
poor terminal connections or damage, poor crimps and
corrosion. The harness cannot be repaired for any of
these conditions, it must be replaced
1. Perform the Diagnostic System Check - Vehicle.
Refer to Diagnostic System Check - Vehicle
in SI.

DTC P0C52:
Low Voltage
DTC P0C53:
High Voltage
DTC P0C5C:
Low Voltage
DTC P0C5D:
High Voltage

Drive Motor 1 Position Sensor Circuit 1
Drive Motor 1 Position Sensor Circuit 1
Drive Motor 1 Position Sensor Circuit 2
Drive Motor 1 Position Sensor Circuit 2

Parts Information
Causal
Part

Description

Part
Number

Qty

X

HARNESS,
A/TRNS WRG
CONT
VALVE SOL

24285319

1

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

Description

Labor Time

8463570

Automatic
Transmission Wiring
Harness Replacement

Use Published
Labor
Operation Time

Bulletin No.: 18-NA-186

September, 2019

Page 3

Version Information
Version

4

Modified

Released June 04, 2018
June 19, 2018 – Corrected the replacement Harness Part Number to the affected DTC.
Added South Korea to Involved Region or Country.
September 27, 2018 – Changed the date in Step #3 and Step #4 from 02/12/2018 to
04/07/2018.
September 17, 2019 – Revised the Subject and the Bulletin information to pertain only to
DTC P0A3F or P1B03. Removed all references to DTC P0A45 or P1B04, its associated
repair procedure, Wiring Harness Part Number Information and Warranty Information.
Removed the Keywords DTC P0C57, P0C58, P0C61 and P0C62.

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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