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 in to 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 in the antenna coil.

DTC No. DTC Detection Condition Trouble Area
B2784 When performing immobiliser set/unset, the antenna coil circuit is opened or shorted for 5 seconds.

  • Wire harness or connector

  • Transponder key amplifier

  • Transponder key ECU

WIRING DIAGRAM

A011833E17

INSPECTION PROCEDURE

Note

If the transponder key ECU is replaced, register the key and ECU - ECM communication ID.

PROCEDURE


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


    1. A0117FNE02
      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)

      Disconnect the D29 transponder key ECU connectors.

    2. Disconnect the D24 transponder key amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D29-4 (TXCT) - D31-5 (TXCT) Always Below 1 Ω
      D29-5 (AGND) - D31-7 (AGND) Always Below 1 Ω
      D29-14 (VC5) - D31-1 (VC5) Always Below 1 Ω
      D29-15 (CODE) - D31-4 (CODE) Always Below 1 Ω
      D29-4 (TXCT) - Body ground Always 10 kΩ or higher
      D29-5 (AGND) - Body ground Always 10 kΩ or higher
      D29-14 (VC5) - Body ground Always 10 kΩ or higher
      D29-15 (CODE) - Body ground Always 10 kΩ or higher

    4. Reconnect the amplifier and ECU connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT TRANSPONDER KEY ECU (TRANSPONDER KEY AMPLIFIER POWER SOURCE AND GROUND)

    A0119NVE02
    Text in Illustration
    *1

    Component with harness connected

    (Transponder Key ECU)

    1. Measure the voltage and resistance according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      D29-14 (VC5) - Body ground No key is in ignition key cylinder Below 1 V
      Key is in ignition key cylinder 4.6 to 5.4 V
      D29-5 (AGND) - Body ground Always Below 1 Ω

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D29-5 (AGND) - Body ground Always Below 1 Ω

    NG

    REPLACE TRANSPONDER KEY ECU

    OK

  3. REPLACE TRANSPONDER KEY AMPLIFIER


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


    NEXT

  4. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  5. 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)