TECHNICAL INSTRUCTIONS
FOR
SPECIAL SERVICE CAMPAIGN 22TC11
SOFTWARE UPDATE – DC COLD WEATHER CHARGING
CERTAIN 2023 MODEL YEAR bZ4X

The repair quality of covered vehicles is extremely important to Toyota. All dealership technicians
performing this repair are required to successfully complete the most current version of the E-Learning
course “Safety Recall and Service Campaign Essentials”. To ensure that all vehicles have the repair
performed correctly; technicians performing this repair are required to currently hold at least one of the
following certification levels:
• Expert Technician (Hybrid)
Always check which technicians can perform the repair by logging on to
https://www.uotdealerreports.com. It is the dealership’s responsibility to select technicians with the
above certification level or greater to perform this repair. Carefully review your resources, the technician
skill level, and ability before assigning technicians to this repair. It is important to consider technician
days off and vacation schedules to ensure there are properly trained technicians available to perform this
repair at all times.

I.

OPERATION FLOW CHART

The flow chart is for reference only. DO NOT use it in place of the full technical instructions. Follow ALL
steps as outlined in the full technical instructions to confirm the campaign is completed correctly.
Verify Vehicle Eligibility
1. Confirm vehicle VIN matches RO
2. Check Vehicle Inquiry System for
campaign eligibility

Not Covered

No further action required

Covered
Perform Health Check and Verify the
Calibration ID’s of the 5 ECU’s (2WD)
or 6 ECU’s (AWD) listed in the TI
Old Calibration
Download both ECU reprogramming
package files
Reflash applicable ECU’s for package 1
2WD – EV, MG(FR), BAT
AWD – EV, MG(FR), MG(RR), BAT
Perform verification Health Check and
clear any DTC’s

New Calibration

Reflash applicable ECU’s for package 2
2WD – PWC, A/C
AWD – PWC, A/C
Perform verification Health Check and
clear any DTC’s

Campaign complete.
Return the vehicle to the customer.

II. IDENTIFICATION OF AFFECTED VEHICLES

1. CHECK VEHICLE FOR CAMPAIGN ELIGIBILITY
a) Compare the vehicles VIN to the VIN listed on the Repair Order to ensure they match.
b) Check the TIS Vehicle Inquiry System to confirm the VIN is involved in this Limited Service Campaign, and
that it has not already been completed.
NOTICE:
TMNA warranty will not reimburse dealers for repairs completed on vehicles that are not affected or
were previously completed, even by another dealer.

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III. PREPARATION
A. TOOLS & EQUIPMENT
•
•
•

Standard Hand Tools
• DCA-8000 Battery Diagnostic Station
T-SB-0134-16
• T-SB-0107-20
Techstream ADVi / Techstream 2.0 / Techstream Lite

IV. BACKGROUND

A software update has been developed for certain 2023 model year bZ4X vehicles. Included in the update is an
improvement of DC fast charging performance during low temperatures.
The software update will require reprogramming each of the following ECUs using Techstream: EV, MG, BAT, PWC
and A/C.

*C

for AWD

-

-

*1

PWC ECU
(ELECTRIC CONVERTER UNIT ASSEMBLY)

*2

MG ECU
(FR E-AXLE ASSEMBLY)

*3

MG ECU
(RR E-AXLE ASSEMBLY)

*4

BAT ECU
(EV SUPPLY BATTERY ASSEMBLY)

*5

EV ECU
(EV CONTROL ECU)

*6

A/C ECU
(AIR CONDITIONING AMPLIFIER ASSEMBLY)

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V. SAFETY PRECAUTIONS
CRITICAL INFORMATION - READ THOROUGHLY
An ECU could be damaged if an error occurs in the communication while reprogramming the ECU. Confirm all work
is performed as described in these instructions.

1. CONFIRM TECHSTREAM IS THE LATEST VERSION
2. CONFIRM D/C CUT (30A) FUSE HAS BEEN INSTALLED

a) In order to perform ECU reprogramming the cut fuse must be in location *b. If Pre-Delivery Service (PDS) was
not performed on the vehicle, please remove cut fuse from location *a and install into location *b.

*1
*a

Relay Block
Remove D/C CUT FUSE (30A)

*b

Install D/C CUT FUSE (30A) (Original Location)

3. STABILIZE THE POWER TO THE PERSONAL COMPUTER SIDE
a) Be sure to connect the personal computer to an external AC power
supply.
NOTICE:
The ECU could be damaged if the battery voltage of the personal
computer drops while reprogramming.

3

b) Turn off the screen saver and power saving mode of the personal
computer so that the power to the hard disk is kept supplied.
NOTICE:
If the screen saver or power saving mode launches while
reprogramming, the communication may be disconnected,
resulting in the damage of the ECU.
c) DO NOT block the ventilation opening for the cooling fan of the
personal computer.
NOTICE:
If the ventilation opening for the cooling fan is blocked with a
sheet cover or the like, the personal computer may be heated
excessively, causing the operation of the personal computer to
stop.
Due to the stop of the operation, the communication for
reprogramming signals could be stopped, resulting in the damage
of the ECU.

VI. CALIBRATION ID VERIFICATION
1. CHECK FOR DTC’S
a) Using a Techstream, perform a Health Check to check for any
Diagnostic Trouble Codes.
NOTICE:
This Campaign covers only the software update to the ECUs
detailed in these instructions. It does not cover the diagnosis or
replacement of any other systems on the vehicle.

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2. CHECK CURRENT CALIBRATION
a) Locate the calibration ID of the ECU’s that require reprogramming to determine if an update is available.
b) Determine the status of an available update; indicated by a YES or NO.
HINT:
If the CID’s indicate ‘Yes’, proceed with the update procedure.
The ECUs that require reprogramming

(●: Require, -: Do not require)

Drive Type

EV ECU
(EV)

MG ECU
(Motor
Generator)

MG ECU
(Rear Motor
Generator)

BAT ECU
(EV Battery)

PWC ECU
(Plug-in
Control)

A/C ECU
(Air
Conditioner)

2WD
AWD

●
●

●
●

●

●
●

●
●

●
●

*1

EV ECU

*2

MG ECU

*3

MG ECU (Only for 4WD models)

*4

BAT ECU

*5
*6
PWC ECU
A/C ECU
Notice: You will need to scroll the ECU menu to find all ECU cals.

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Drive
Type

2WD

AWD

Calibrations

System

Current
Calibration ID

EV

8A2524237000

8A2524224200

Motor Generator

8A2814201200

898844236000

EV Battery

8989F4204100

8989F4601100

Plug-in Control

892634212000

892634218000

Air Conditioner

8865F4213002

8865F4213100

EV

8A2524238000

8A2524225200

Motor Generator

8A2814202200

898844237000

Rear Motor
Generator

8A2914201200

898844238000

EV Battery

8989F4210100

8989F4210200

Plug-in Control