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

DTC Code DTC Name
B2784 Antenna Coil Open / Short

DESCRIPTION

The transponder key coil is built into the transponder key amplifier and receives a key code signal from the transponder chip in the key. This signal is amplified by the amplifier, then it is output to the transponder key ECU assembly.

DTC No. DTC Detection Condition Trouble Area
B2784 Antenna coil is open/shorted.

  • Wire harness or connector

  • Transponder key amplifier

  • Transponder key ECU assembly

WIRING DIAGRAM

A01EJUPE02

INSPECTION PROCEDURE

Note

If the transponder key ECU assembly is replaced, register the key and ECU communication ID (Service Bulletin).

PROCEDURE


  1. READ VALUE USING GTS (KEY SW)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Immobiliser / Data List.

    5. Read the Data List according to the display on the GTS.

      Immobiliser (Transponder Key ECU Assembly)
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Antenna Coil Status Transponder key amplifier coil condition/Normal or Fail

      Normal: Antenna coil normal

      Fail: Antenna coil malfunctioning

      		 -
      OK
      On the GTS screen, the item displays Normal according to the chart above.

    NG

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

    OK

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

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


    1. Disconnect the transponder key ECU assembly connector.

    2. A01EJ2CE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Transponder Key ECU Assembly)
      *2

      Front view of wire harness connector

      (to Transponder Key Amplifier)

      Disconnect the transponder key amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D22-4 (TXCT) - D21-5 (TXCT) Always Below 1 Ω
      D22-5 (AGND) - D21-7 (AGND) Always Below 1 Ω
      D22-14 (VC5) - D21-1 (VC5) Always Below 1 Ω
      D22-15 (CODE) - D21-4 (CODE) Always Below 1 Ω
      D22-4 (TXCT) - Body ground Always 10 kΩ or higher
      D22-5 (AGND) - Body ground Always 10 kΩ or higher
      D22-14 (VC5) - Body ground Always 10 kΩ or higher
      D22-15 (CODE) - Body ground Always 10 kΩ or higher
      D21-5 (TXCT) - Body ground Always 10 kΩ or higher
      D21-7 (AGND) - Body ground Always 10 kΩ or higher
      D21-1 (VC5) - Body ground Always 10 kΩ or higher
      D21-4 (CODE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT TRANSPONDER KEY AMPLIFIER (POWER SOURCE AND GROUND)


    1. Reconnect the transponder key ECU assembly connector.

    2. A01EM8OE01
      Text in Illustration
      *1

      Component with harness connected

      (Transponder Key ECU Assembly)

      Reconnect the transponder key amplifier connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      D22-14 (VC5) - Body ground No key is in ignition key cylinder Below 1 V
      D22-14 (VC5) - Body ground Key is in ignition key cylinder 4.6 to 5.4 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      D22-5 (AGND) - Body ground Always Below 1 Ω

    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

    OK

    REPLACE TRANSPONDER KEY AMPLIFIER Click here