IMMOBILISER SYSTEM(w/ Entry and Start System), Diagnostic DTC:B279A, B279A12

DTC Code DTC Name
B279A Theft Deterrent System Communication Line High Fixation
B279A12 Engine Immobiliser System Circuit Short to Battery

DESCRIPTION

If the communication line (IMI - EFIO) between the ECM and ID code box (immobiliser code ECU) is stuck high, the ECM will store this DTC.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B279A Theft Deterrent System Communication Line High Fixation The communication line (IMI - EFIO) between the ECM and ID code box (immobiliser code ECU) is stuck high. (1 trip detection logic*)

  • ID code box (immobiliser code ECU)

  • ECM

  • Wire harness or connector

DTC output confirmation operation:


  • Turn the engine switch on (IG) and wait 6 seconds.
B279A12 Engine Immobiliser System Circuit Short to Battery The communication line (IMI - EFIO) between the ECM and ID code box (immobiliser code ECU) is stuck high. (1 trip detection logic*)

  • ID code box (immobiliser code ECU)

  • ECM

  • Wire harness or connector

DTC output confirmation operation:


  • Turn the engine switch on (IG) and wait 6 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 Engine cannot be started
Related Data List and Active Test
DTC No. Data List and Active Test

  • B279A12*1

  • B279A*2

 -

WIRING DIAGRAM

A001TG5E18
*a ID Code Box (Immobiliser Code ECU)

CAUTION / NOTICE / HINT

Note


  • When using the GTS with the engine switch off, connect the GTS to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus: Body Electrical / Entry&Start(CAN). While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.

  • Before replacing the ECM or ID code box (immobiliser code ECU), refer to Service Bulletin.

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

Tech Tips

When DTC B279A12*1 or B279A*2 and a certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.


PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.


      1. Clear the DTCs.

        Click here


        Powertrain > Engine > Clear DTCs

    2. for 3ZR-FAE


      1. Clear the DTCs.

        Click here


        Powertrain > Engine and ECT > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Turn the engine switch on (IG) and wait 10 seconds.

    2. Check for DTCs.


      1. Check for DTCs.

        Click here


        Powertrain > Engine > Trouble Codes

        Tech Tips

        If DTCs other than DTC B279A12 are output, troubleshoot those DTCs first.

    3. for 3ZR-FAE


      1. Check for DTCs.

        Click here


        Powertrain > Engine and ECT > Trouble Codes

        Tech Tips

        If DTCs other than DTC B279A are output, troubleshoot those DTCs first.

      Result
      Result Proceed to
      Only DTC B279A12*1 or B279A*2 is output A
      DTC B279A12*1 or B279A*2 and other DTCs are output B

      • *1: for 8NR-FTS

      • *2: for 3ZR-FAE


    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  3. CHECK CONNECTION OF CONNECTOR


    1. Turn the engine switch off.

    2. Check that the connectors are properly connected to the ECM and ID code box (immobiliser code ECU).

      OK
      Connectors are properly connected.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  4. CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM)


    1. Disconnect the F21 ID code box (immobiliser code ECU) connector.

    2. Disconnect the A38 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F21-4 (EFIO) - A38-28 (IMI) Always Below 1 Ω
      F21-4 (EFIO) or A38-28 (IMI) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU) with a new one.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  6. REGISTER RECOGNITION CODE


    1. Register the recognition codes in the ECUs.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  7. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  8. CHECK WHETHER ENGINE STARTS


    1. Check that the engine starts.

      OK
      Engine starts normally.
      Result
      Result Proceed to
      OK A
      NG (for 8NR-FTS) B
      NG (for 3ZR-FAE) C

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    A

  9. CLEAR DTC


    1. for 8NR-FTS


      1. Clear the DTCs.

        Click here


        Powertrain > Engine > Clear DTCs

    2. for 3ZR-FAE


      1. Clear the DTCs.

        Click here


        Powertrain > Engine and ECT > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. for 8NR-FTS


      1. Check for DTCs.

        Click here


        Powertrain > Engine > Trouble Codes
        OK
        DTC B279A12 is not output.

    3. for 3ZR-FAE


      1. Check for DTCs.

        Click here


        Powertrain > Engine and ECT > Trouble Codes
        OK
        DTC B279A is not output.
      Result
      Result Proceed to
      OK A
      NG (for 8NR-FTS) B
      NG (for 3ZR-FAE) C

    A

    END (ID CODE BOX (IMMOBILISER CODE ECU) WAS DEFECTIVE)

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here