IMMOBILISER SYSTEM(w/o 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. Detection Item DTC Detection Condition Trouble Area Note
B2784 Antenna Coil Open / Short

Any of the following conditions is met:


  • The antenna coil in the transponder key coil is open (1 trip detection logic*1).

  • The antenna coil in the transponder key coil is shorted (1 trip detection logic*1).

  • Wire harness or connector

  • Transponder key coil

  • Transponder key ECU assembly

    DTC Output Confirmation Operation:

  • Insert the key into the ignition key cylinder.

DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition Always ○ ○
Malfunction Status The antenna coil in the transponder key coil is open. ○ -
The antenna coil in the transponder key coil is shorted. - ○
Detection Time - -
Number of Trips 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

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

A001U8RE06
*a Transponder Key Coil
*b Transponder Key ECU Assembly

CAUTION / NOTICE / HINT

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.


      Body Electrical > Immobiliser > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs.


      Body Electrical > Immobiliser > Trouble Codes

      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

    USE SIMULATION METHOD TO CHECK Click here

    B

  3. CHECK CONNECTION OF CONNECTOR


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

      Result
      Proceed to
      NEXT

    NEXT

  4. CLEAR DTC


    1. Clear the DTCs.


      Body Electrical > Immobiliser > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR DTC


    1. Check for DTCs.


      Body Electrical > Immobiliser > Trouble Codes

      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.

      A001T6WC30
      *a

      Component with harness connected

      (Transponder Key Coil)

      		 *b Waveform 1
      *c Waveform 2 - -
      Waveform 1
      Item Content
      Tester Connection F79-1 (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 F79-5 (ANT2) ←→ Body ground
      Tool Setting 20 V/DIV., 2 s./DIV.
      Tool Setting Within 3 seconds of inserting key into ignition key cylinder
      OK
      Waveform is similar to that shown in the illustration
      Result
      Proceed to
      OK
      NG

    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 F22 transponder key ECU assembly connector.

    2. Disconnect the F79 transponder key coil connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F22-4 (ANT1) - F79-1 (ANT1) Always Below 1 Ω
      F22-15 (ANT2) - F79-5 (ANT2) Always Below 1 Ω
      F22-4 (ANT1) - Body ground Always 10 kΩ or higher
      F79-1 (ANT1) - Body ground Always 10 kΩ or higher
      F22-15 (ANT2) - Body ground Always 10 kΩ or higher
      F79-5 (ANT2) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    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.

      Result
      Proceed to
      NEXT

    NEXT

  9. CLEAR DTC


    1. Clear the DTCs.


      Body Electrical > Immobiliser > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK FOR DTC


    1. Check for DTCs.


      Body Electrical > Immobiliser > Trouble Codes

      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