ENGINE IMMOBILISER SYSTEM(w/o Power Switch), Diagnostic DTC:B2784

DTC Code DTC Name
B2784 Antenna Coil Open / Short

DESCRIPTION

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

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2784 The antenna coil built into the transponder key coil is open or shorted (determined by communication with transponder key ECU assembly) (1 trip detection logic*).

  • Harness or connector

  • Transponder key coil

  • Transponder key ECU assembly

 Insert the key into the ignition key cylinder.

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 Code Data List and Active Test
B2784 Antenna Coil Status

WIRING DIAGRAM

A01V1L8E57
*a Transponder Key ECU Assembly
*b Transponder Key Coil

CAUTION / NOTICE / HINT

Note


  • When replacing the transponder key ECU assembly, refer to the Service Bulletin.

  • After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

      Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

      OK
      DTC B2784 is not output.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. CHECK CONNECTION OF CONNECTOR


    1. Check that the connectors are properly connected to the transponder key coil.


    NEXT

  4. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  5. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

      Before checking for DTCs, perform "DTC Output Confirmation Operation" procedure.

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

    A

    END (CONNECTOR WAS NOT CONNECTED PROPERLY)

    B

  6. CHECK TRANSPONDER KEY COIL (OUTPUT)


    1. Using an oscilloscope, check the waveform.

      A01V0AOE02
      Text in Illustration
      *a

      Component with harness connected

      (Transponder Key Coil)

      		 *b Waveform 1
      *c Waveform 2 - -
      Waveform 1
      Item Content
      Tester Connection F77-1 (ANT1) - Body ground
      Tool Setting 20 V/DIV., 2 s./DIV.
      Condition Within 3 seconds of inserting key into ignition key cylinder
      Waveform 2
      Item Content
      Tester Connection F77-5 (ANT2) - Body ground
      Tool Setting 20 V/DIV., 2 s./DIV.
      Condition Within 3 seconds of inserting key into ignition key cylinder
      OK
      Waveform is similar to that shown in the illustration

    OK

    REPLACE TRANSPONDER KEY COIL Click here

    NG

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


    1. Disconnect the F40 transponder key ECU assembly connector.

    2. Disconnect the F77 transponder key coil connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F40-4 (ANT1) - F77-1 (ANT1) Always Below 1 Ω
      F40-15 (ANT2) - F77-5 (ANT2) Always Below 1 Ω
      F40-4 (ANT1) - Body ground Always 10 kΩ or higher
      F77-1 (ANT1) - Body ground Always 10 kΩ or higher
      F40-15 (ANT2) - Body ground Always 10 kΩ or higher
      F126-5 (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. Check for DTCs Click here.

      Tech Tips

      Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

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

    A

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE TRANSPONDER KEY COIL Click here