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

DTC Code DTC Name
B2784 Antenna Coil Open / Short

DESCRIPTION

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

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

DTC Code DTC Detection Condition Trouble Area
B2784 The antenna coil is open/shorted.

  • Harness or connector

  • Transponder key ECU

  • Transponder key amplifier

WIRING DIAGRAM

A003AUDE28

INSPECTION PROCEDURE

Tech Tips

When the transponder key ECU is replaced, reregister the ECU - ECM communication ID.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B2784 is not output.

    NG

    READ VALUE USING INTELLIGENT TESTER (ANTENNA COIL) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. READ VALUE USING INTELLIGENT TESTER (ANTENNA COIL)


    1. Use the Data List to check if the transponder key coil is functioning properly.

      OK
      Normal (the antenna coil is normal) appears on the screen.
      Immobiliser
      Tester Display Measurement Item/Display Normal Condition Diagnostic Note
      Antenna Coil Antenna coil condition / Normal or Fail

      Normal: Antenna coil normal

      Fail: Antenna coil malfunctioning

      		 -

    NG

    CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER) Click here

    OK

    REPLACE TRANSPONDER KEY ECU

  4. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)

    A003C8IE01
    Text in Illustration
    *1

    Front view of wire harness connector

    (to Transponder Key ECU)
    *2

    Front view of wire harness connector

    (to Transponder Key Amplifier)

    1. Disconnect the D102 ECU connector.

    2. Disconnect the D103 amplifier connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      D102-14 (VC5) - D103-1 (VC5) Always Below 1 Ω
      D102-15 (CODE) - D103-4 (CODE)
      D102-4 (TXCT) - D103-5 (TXCT)
      D102-5 (AGND) - D103-7 (AGND)
      D102-14 (VC5) or D103-1 (VC5) - Body ground Always 10 kΩ or higher
      D102-15 (CODE) or D103-4 (CODE) - Body ground
      D102-4 (TXCT) or D103-5 (TXCT) - Body ground
      D102-5 (AGND) or D103-7 (AGND) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE TRANSPONDER KEY AMPLIFIER


    1. Temporarily replace the transponder key amplifier with a new or normally functioning one Click here.


    NEXT

  6. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  7. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B2784 is not output.

    NG

    REPLACE TRANSPONDER KEY ECU

    OK

    END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)