T-SB-0032-19

Rev1

March 19, 2019

MIL ON DTC P0A1F94
Service
Category

Engine/Hybrid System

Section

Hybrid/Battery Control System

Market USA

Applicability
YEAR(S)

MODEL(S)

ADDITIONAL INFORMATION

2017

Prius Prime

Body Type(s): 4D, 5Dr. Sedan

REVISION NOTICE
June 17, 2019 Rev1:
 The Diagnostic Trouble Code (DTC) and has been updated.
 The Required Tools and Equipment section has been updated.
Any previous printed versions of this bulletin should be discarded.

Introduction

Some 2017 model year Prius Prime vehicles may exhibit a MIL ON condition with Diagnostic
Trouble Code (DTC) P0A1F94 (Battery Energy Control Module [BECM] Unexpected Operation)
when the ignition switch is on and the vehicle is in “Ready Off” status for at least 5 minutes.
Follow the Repair Procedure in this bulletin to address this condition.

Warranty Information
OP CODE

DESCRIPTION

TIME

OFP

T1

T2

EL1905

Reprogram BECM

0.8

89890-47110

8A

74

APPLICABLE WARRANTY
 This repair is covered under the Toyota Hybrid System Warranty. This warranty is in effect for
96 months or 100,000 miles, whichever occurs first, from the vehicle’s in-service date.
 Warranty application is limited to occurrence of the specified condition described in
this bulletin.
 For California Prius Prime vehicles sold, registered, and normally operated in California,
Connecticut, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Rhode Island,
and Vermont, the California Emissions Defect and Performance Warranty coverage i s 180
months from the date of first use, or 150,000 miles, whichever occurs first, from the vehicle's
in-service date.

© 2019 Toyota Motor Sales, USA

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March 19, 2019

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MIL ON DTC P0A1F94
Parts Information
PART NUMBER
PREVIOUS

NEW

89890-47110

89890-47111

00451-00001-LB L

PART NAME

QTY

Battery Energy Control Module (BECM)

–

Authorized Modifications Labels

1

NOTE
 The BECM should NOT be replaced as part of the Repair Procedure.
 Authorized Modifications Labels may be ordered in packages of 25 from the Materials
Distribution Center (MDC) through Dealer Daily – Parts – Dealer Support Materials Orders.

Required Tools & Equipment
REQUIRED EQUIPMENT

SUPPLIER

Techstream ADVi*

QTY

TSADVUNIT

Techstream 2.0
Techstream Lite

PART NUMBER

TS2UNIT
ADE

Techstream Lite (Green Cable)

1

TSLITEPDLR01
TSLP2DLR01

*Essential SST.

NOTE
 Only ONE of the Techstream units listed above is required.
 Software version 14.10.028 or later is required.
 Additional Techstream units may be ordered by calling Approved Dealer Equipment (ADE)
at 1-800-368-6787.
 Use Techstream or an approved J2534 interface to perform flash reprogramming updates.
Visit techinfo.toyota.com for more information regarding J2534 reprogramming.

SPECIAL SERVICE TOOLS (SST)

PART NUMBER

QTY

GR8 Battery Diagnostic Station*

00002-MCGR8

1

*Essential SST.

NOTE
Additional SSTs may be ordered by calling 1-800-933-8335.

© 2019 Toyota Motor Sales, USA

T-SB-0032-19

Rev1

March 19, 2019

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MIL ON DTC P0A1F94
Calibration Information
MODEL

Prius Prime

ECU TYPE

CALIBRATION ID
PREVIOUS

NEW

Main

8989F4702000

8989F4702100

Sub

8989G4702000

8989G4702100

Repair Procedure

1. Confirm the condition exists.
Is DTC P0A1F94 present when the ignition switch is ON and the vehicle is in “Ready Off” status
for AT LEAST 5 minutes?


YES — Continue to step 2.



NO — This bulletin does NOT apply. Continue diagnosis using the applicable
Repair Manual.

© 2019 Toyota Motor Sales, USA

T-SB-0032-19

Rev1

March 19, 2019

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MIL ON DTC P0A1F94
Repair Procedure (continued)

2. Use Techstream to confirm if the BECM calibration has been updated and check for the
Authorized Modifications Label affixed to the vehicle in the location shown below.
Is the calibration ID listed in Techstream and on the label the latest BECM calibration?


YES — This bulletin does NOT apply. Continue diagnosis using the applicable
Repair Manual.
NO — Continue to step 3.



Figure 1. Location of Authorized Modifications Label on 2017 Prius Prime

TOYOTA MOTOR CORPORATION
A UTHORIZE D

M OD IF IC A TIONS

THE FOLLOWING MODIFICATIONS HAVE BEEN MADE:
1
2

THESE MODIFICATIONS HAVE BEEN APPROVED
AS APPROPRIATE BY EPA AND CARB
3

DEALER CODE:
CHANGE AUTHORITY:

4

DATE:

5

1

Replacement BECM Part Num ber
(e.g., 89890-47111)

4

Date Com pleted

2

New Calibration ID (e.g., 8989F4702100)

5

This SB Num ber

3

Dealer Code

© 2019 Toyota Motor Sales, USA

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March 19, 2019

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MIL ON DTC P0A1F94
Repair Procedure (continued)

3. Flash reprogram the BECM.
NOTE
 The GR8 battery diagnostic station MUST be used in Power Supply Mode to maintain
battery voltage at 13.5V while flash reprogramming the vehicle.
 For details on how to use the GR8 battery diagnostic station, refer to the GR8 Instruction Manual
located at TIS – Diagnostics – Tools & Equipment – Battery Diagnostics.

Follow the procedures outlined in Service Bulletin T-SB-0134-16, Techstream ECU Flash
Reprogramming Procedure, and flash the BECM with the NEW calibration file update.

4. Prepare and install the Authorized Modifications Label.
A. Using a permanent marker, enter the following information on the label:
 BECM part number [Refer to the Parts Information section for the NEW
PART NUMBER]





Calibration ID(s) [Refer to the Calibration Information section for the
NEW CALIBRATION ID]
Dealer Code
Repair Date
Change Authority [This bulletin number]

B. Install the Authorized Modifications Label onto the vehicle at the location shown in
Figure 1. The Authorized Modifications Label is available through the MDC,
P/N 00451-00001-LBL.

5. Test-drive the vehicle to confirm proper operation.

© 2019 Toyota Motor Sales, USA