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ENGINE IMMOBILISER SYSTEM (w/o Entry and Start System), Diagnostic DTC:B2784

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DTC Code DTC Name
B2784 Antenna Coil Open / Short
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DESCRIPTION

The antenna coil receives key code signals from the transponder chip in the key grip. The antenna coil is built into the transponder key amplifier, which amplifies the key code signals and outputs the signals to the transponder key ECU assembly.

This DTC is stored when there is an open or short in the antenna coil.

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2784

The antenna coil built into the transponder key amplifier is open or shorted (determined by communication with the transponder key ECU assembly) (1 trip detection logic*).


  • Terminal VC5, TXCT or CODE is open.

  • The antenna coil built into the transponder key amplifier is open.

  • Harness or connector

  • Transponder key amplifier

  • Transponder key ECU assembly

 Insert the key into the ignition key cylinder.

Table 1. Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
Engine cannot be started -
Table 2. Related Data List and Active Test
DTC Code Data List and Active Test
B2784 Antenna Coil Status
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INSPECTION PROCEDURE

Note:

  • When replacing the transponder key ECU assembly, refer to the Service Bulletin.

  • After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

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PROCEDURE


  1. Click here

    CLEAR DTC


    1. Clear the DTCs (Click here).


  2. Click here

    CHECK FOR DTC


    1. Check for DTCs (Click here).

      Tip:

      Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

      OK
      DTC B2784 is not output.

  3. Click here

    CHECK TRANSPONDER KEY AMPLIFIER (OUTPUT)


    1. A0158SUE05

      Using an oscilloscope, check the waveform.

      Table 3. Text in Illustration
      *a

      Component with harness connected

      (Transponder Key Amplifier)
      *b Waveform

      1. Waveform (Reference)

        Table 4. Measurement Condition
        Item Content
        Tester Connection E95-4 (CODE) - E95-7 (AGND)
        Tool Setting 1 V/DIV., 100 μs./DIV.
        Condition Key inserted in ignition key cylinder
        OK
        Waveform is output normally (refer to illustration).

  4. Click here

    REPLACE TRANSPONDER KEY ECU ASSEMBLY


    1. Replace the transponder key ECU assembly (refer to the Service Bulletin).


  5. Click here

    REGISTER KEY


    1. Reregister the key (refer to the Service Bulletin).


  6. Click here

    REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID (refer to the Service Bulletin).


  7. Click here

    CLEAR DTC


    1. Clear the DTCs (Click here).


  8. Click here

    CHECK FOR DTC


    1. Check for DTCs (Click here).

      Tip:

      Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

      OK
      DTC B2784 is not output.

  9. Click here

    USE SIMULATION METHOD TO CHECKClick here

  10. Click here

    REPLACE TRANSPONDER KEY AMPLIFIERClick here

  11. Click here

    REPLACE TRANSPONDER KEY AMPLIFIERClick here

  12. Click here

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)