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Home >> Lexus >> 2021 >> ES 300h Base >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (A25A-FXS) - Service Information >> ECM >> Removal [09/2022 - ] >> Procedure
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Removal [09/2022 - ]: Procedure

  1. PRECAUTION 
    NOTE:

    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.

  2. PRECAUTION (for LITHIUM-ION BATTERY) 

    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.

    NOTE:
    • 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.
    1. 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.

  3. DISCONNECT CABLE FROM NEGATIVE AUXILIARY BATTERY TERMINAL 

    Refer to PROCEDURE - Step 1

  4. REMOVE ECM 
    1. Rotate the 2 levers while pushing the locks, and disconnect the 2 ECM connectors.
      NOTE:

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

      GTY762840Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Remove the bolt and separate the engine wire from the No. 2 ECM bracket.
    3. Disengage the clamp.
    4. Remove the 2 nuts and ECM.
      GTY762835Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE:

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

  5. REMOVE NO. 1 ECM BRACKET 
    1. Remove the 2 screws and No. 1 ECM bracket from the ECM.
      GTY762834Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. REMOVE NO. 2 ECM BRACKET 
    1. Remove the 2 screws and No. 2 ECM bracket from the ECM.
      GTY762833Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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