ENGINE IMMOBILISER SYSTEM (w/o Smart Key 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

A011SD1E08

INSPECTION PROCEDURE

Note

If the transponder key ECU assembly is replaced, refer to Registration Click here.

PROCEDURE

  1. READ VALUE USING TECHSTREAM

    1. Connect the Techstream to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the Techstream on.

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

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

      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 Techstream screen, "Normal" is displayed.
    NG

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

    OK

    REPLACE TRANSPONDER KEY ECU ASSEMBLY Click here

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

    1. Disconnect the transponder key ECU assembly connector.

    2. 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
      I19-4 (TXCT) - I34-5 (TXCT) Always Below 1 Ω
      I19-5 (AGND) - I34-7 (AGND) Always Below 1 Ω
      I19-14 (VC5) - I34-1 (VC5) Always Below 1 Ω
      I19-15 (CODE) - I34-4 (CODE) Always Below 1 Ω
      I19-4 (TXCT) - Body ground Always 10 kΩ or higher
      I19-5 (AGND) - Body ground Always 10 kΩ or higher
      I19-14 (VC5) - Body ground Always 10 kΩ or higher
      I19-15 (CODE) - Body ground Always 10 kΩ or higher
      I34-5 (TXCT) - Body ground Always 10 kΩ or higher
      I34-7 (AGND) - Body ground Always 10 kΩ or higher
      I34-1 (VC5) - Body ground Always 10 kΩ or higher
      I34-4 (CODE) - Body ground Always 10 kΩ or higher
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    1. Reconnect the transponder key ECU assembly connector.

    2. Reconnect the transponder key amplifier connector.

      A011S5WE17

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I19-14 (VC5) - Body ground No key in ignition key cylinder Below 1 V
      I19-14 (VC5) - Body ground Key in ignition key cylinder 4.6 to 5.4 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      I19-5 (AGND) - Body ground Always Below 1 Ω
      Text in Illustration
      *a

      Component with harness connected

      (Transponder Key ECU Assembly)
    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY Click here

    OK

    REPLACE TRANSPONDER KEY AMPLIFIER Click here