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

DTC Code DTC Name
B2784 Antenna Coil Open / Short

DESCRIPTION

When an open or short circuit is detected in the antenna coil built into the transponder key coil, the transponder key ECU assembly stores this DTC.

DTC No. DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2784 The antenna coil in the transponder key coil is open/shorted.

  • Wire harness or connector

  • Transponder key coil

  • Transponder key ECU assembly

 Insert the door control transmitter assembly into the ignition key cylinder, turn the ignition switch from off to ON and wait at least 20 seconds.
Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
Engine cannot be started -
Related Data List and Active Test
DTC No. Data List and Active Test
B2784 Antenna Coil Status

WIRING DIAGRAM

B000HK5E31

INSPECTION PROCEDURE

Note


  • If the transponder key ECU assembly is replaced, refer to Service Bulletin.

  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs Click here.

      OK
      DTC B2784 is not output.
      Result
      Result Proceed to
      B2784 is not output A
      B2784 is output B

    B

    CHECK CONNECTION OF CONNECTOR Click here

    A

    USE SIMULATION METHOD TO CHECK Click here

  3. CHECK CONNECTION OF CONNECTOR


    1. Check that the connector is properly connected to the transponder key coil.


    NEXT

  4. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  5. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs. Click here.

      OK
      DTC B2784 is not output.
      Result
      Result Proceed to
      B2784 is not output A
      B2784 is output B

    B

    CHECK TRANSPONDER KEY COIL (OUTPUT) Click here

    A

    END (CONNECTOR WAS NOT CONNECTED PROPERLY)

  6. CHECK TRANSPONDER KEY COIL (OUTPUT)


    1. Using an oscilloscope, check the waveform.

      B000M92E15
      OK
      Tester Connection Condition Tool Setting Specified Condition
      I191-1 (ANT1) - Body ground Within 3 seconds of inserting door control transmitter assembly into ignition key cylinder 2 V/DIV., 500 ms./DIV.

      Pulse generation

      (See waveform 1)
      I191-5 (ANT2) - Body ground Within 3 seconds of inserting door control transmitter assembly into ignition key cylinder 2 V/DIV., 500 ms./DIV.

      Pulse generation

      (See waveform 2)
      OK
      Waveform is similar to that shown in the illustration.
      Text in Illustration
      *a

      Component with harness connected

      (Transponder Key Coil)

      		 *b Waveform 1
      *c Waveform 2 - -
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE TRANSPONDER KEY ECU ASSEMBLY Click here

    A

  7. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - TRANSPONDER KEY COIL)


    1. Disconnect the I19 transponder key ECU assembly connector.

    2. Disconnect the I191 transponder key coil connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I19-4 (ANT1) - I191-1 (ANT1) Always Below 1 Ω
      I19-15 (ANT2) - I191-5 (ANT2) Always Below 1 Ω
      I19-4 (ANT1) or I191-1 (ANT1) - Body ground Always 10 kΩ or higher
      I19-15 (ANT2) or I191-5 (ANT2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. REPLACE TRANSPONDER KEY ECU ASSEMBLY


    1. Temporarily replace the transponder key ECU assembly with a new one.

      Tech Tips

      Refer to Service Bulletin.

      Note

      Key ID code registration is necessary when replacing the transponder key ECU assembly, refer to Service Bulletin.


    NEXT

  9. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  10. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs Click here.

      OK
      DTC B2784 is not output.
      Result
      Result Proceed to
      B2784 is not output A
      B2784 is output B

    B

    REPLACE TRANSPONDER KEY COIL Click here

    A

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)