Removal [11/2021 - ]: Procedure

NOTE: After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Refer to BEFORE DISCONNECTING BATTERY [11/2021 - ] 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.

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.

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 ignition switch to ON (READY) and wait for 5 minutes or more.
   5. Turn the ignition switch off and wait for 1 minutes or more.
   6. Disconnect the cable from the negative (-) auxiliary battery terminal.
   7. Replace the other ECU.
   8. Connect the cable to the negative (-) auxiliary battery terminal.
   9. Check that the ignition switch can be turned to 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.

Refer to PROCEDURE - Step 2

Refer to PROCEDURE - Step 3

1. Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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 and other foreign matter does not contact the connecting parts of the ECM connectors.

   2. Remove the bolt and disengage the clamp to separate the engine wire.
   3. Remove the bolt, 2 nuts and ECM.
      NOTE:

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

1. Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002