Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001PX5C
Model Year Start: 2021 Model: Avalon HV Prod Date Range: [08/2020 - 08/2021]
Title: A25A-FXS (ENGINE CONTROL): ECM: REMOVAL; 2021 MY Avalon HV [08/2020 - 08/2021]

REMOVAL

CAUTION / NOTICE / HINT

The necessary procedures (adjustment, calibration, initialization or registration) that must be performed after parts are removed and installed, or replaced during ECM removal/installation are shown below.

Necessary Procedures After Parts Removed/Installed/Replaced

Replaced Part or Performed Procedure

Necessary Procedure

Effect/Inoperative Function when Necessary Procedure not Performed

Link

*: When performing learning using the Techstream.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; PARK ASSIST / MONITORING: INTELLIGENT CLEARANCE SONAR SYSTEM (for HV Model): CALIBRATION

Auxiliary battery terminal is disconnected/reconnected

Perform steering sensor zero point calibration

Lane Departure Alert System (w/ Steering Control)

2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; PRE-COLLISION: PRE-COLLISION SYSTEM (for HV Model): INITIALIZATION

Pre-collision System

Intelligent Clearance Sonar System*

Lighting System (for HV Model with Cornering Light)

Memorize steering angle neutral point

Parking Assist Monitor System

2019 - 2022 MY Avalon HV [04/2018 -        ]; PARK ASSIST / MONITORING: PARKING ASSIST MONITOR SYSTEM(for HV Model): INITIALIZATION

Panoramic View Monitor System

2019 - 2022 MY Avalon HV [04/2018 -        ]; PARK ASSIST / MONITORING: PANORAMIC VIEW MONITOR SYSTEM (for HV Model): INITIALIZATION

Replacement of ECM

Perform Vehicle Identification Number (VIN) registration

MIL illuminates

2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: REGISTRATION

NOTICE:

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

    Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION

  • If the ECM has been struck or dropped, replace it.
  • Perform Vehicle Identification Number (VIN) registration when replacing the ECM.

    Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: REGISTRATION

PROCEDURE

1. PRECAUTION

HV battery learning values are stored in the battery ECU assembly and ECM and are used to detect malfunctions and illuminate the hybrid battery indicator light in the combination meter assembly. When either of these ECUs is replaced, the new ECU receives the HV battery learning values from the other ECU and stores them.

NOTICE:

  • Do not replace the battery ECU assembly and ECM at the same time as the HV battery learning values will be lost. However, if it is necessary to replace both ECUs at the same time, replace them by following the procedure below.
  • Do not replace the battery ECU assembly or ECM with a used one from another vehicle.

(a) Procedure when replacing both battery ECU assembly and ECM:

(1) Disconnect the cable from the negative (-) auxiliary battery terminal.

(2) Replace either ECU.

(3) Connect the cable to the negative (-) auxiliary battery terminal.

(4) Turn the power switch on (READY) and wait for 5 minutes or more.

(5) Turn the power switch off and disconnect the cable from the negative (-) auxiliary battery terminal.

(6) Replace the other ECU.

(7) Connect the cable to the negative (-) auxiliary battery terminal.

(8) Check that the power switch can be turned on (READY).

HINT:

If the battery ECU assembly and ECM are replaced at the same time without following the above procedure, replace either the battery ECU assembly and ECM with its original one and then replace it again by following the above procedure. If the correct procedure is not followed, perform the procedure again from the beginning.

2. REMOVE LUGGAGE TRIM SERVICE HOLE COVER

Click here 2020 - 2021 MY Avalon HV [08/2019 - 08/2021]; MAINTENANCE: A25A-FXS AUXILIARY BATTERY: REMOVAL+

3. DISCONNECT CABLE FROM NEGATIVE AUXILIARY BATTERY TERMINAL

Click here 2020 - 2021 MY Avalon HV [08/2019 - 08/2021]; MAINTENANCE: A25A-FXS AUXILIARY BATTERY: REMOVAL+

4. REMOVE ECM

(a) Rotate the 2 levers while pushing the locks, and disconnect the 2 ECM connectors.

NOTICE:

After disconnecting the ECM connectors, make sure that dirt, water and other foreign matter does not contact the connecting parts of the ECM connectors.

(b) Remove the bolt and separate the engine wire from the No. 2 ECM bracket.

(c) Disengage the clamp.

(d) Remove the 2 nuts and ECM.

NOTICE:

If the ECM has been struck or dropped, replace it.

5. REMOVE NO. 1 ECM BRACKET

(a) Remove the 2 screws and No. 1 ECM bracket from the ECM.

6. REMOVE NO. 2 ECM BRACKET

(a) Remove the 2 screws and No. 2 ECM bracket from the ECM.