ENGINE IMMOBILISER SYSTEM, Diagnostic DTC:B279A

DTC Code DTC Name
B279A Theft Deterrent System Communication Line High Fixation

DESCRIPTION

If the communication line (EFIO - IMI) to the ID code box (immobiliser code ECU) is stuck on HI output, the ECM outputs this DTC.

DTC Code DTC Detection Condition Trouble Area
B279A When communication line (EFIO - IMI) between ECM and ID code box (immobiliser code ECU) is stuck on HI output.

  • Wire harness or connector

  • ID code box (immobiliser code ECU)

  • ECM

WIRING DIAGRAM

A01CAZ7E01

INSPECTION PROCEDURE

Note


  • If the ID code box (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID.

  • If the ECM is replaced, register the ECU communication ID.

PROCEDURE


  1. CHECK DTC OUTPUT


    1. Clear the DTCs Click here.

    2. Recheck for DTCs Click here.

      Tech Tips

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

      Result
      Result Proceed to
      DTC B279A is output A
      DTC B279A and other DTCs are output B

    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  2. CHECK HARNESS AND CONNECTOR (ID CODE BOX - ECM)


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

    2. Disconnect the ECM connector.

      A01CDZTE22

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G15-6 (EFIO) - A8-11 (IMI) Always Below 1 Ω
      G15-6 (EFIO) - Body ground Always 10 kΩ or higher

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      G15-6 (EFIO) - Body ground Always Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK ID CODE BOX (IMMOBILISER CODE ECU) (WAVEFORM)


    1. Reconnect the ID code box (immobiliser code ECU) connector.

    2. Reconnect the ECM connector.

    3. Using an oscilloscope, check that the waveform.

      A01CG53E01
      Waveform (Reference)
      Item Content
      Terminal No. (Symbol) G15-6 (EFIO) - G15-8 (GND)
      Tool Setting 5 V/DIV., 50 msec./DIV.
      Condition Engine switch on (IG)
      OK
      Waveform is output normally (see illustration).
      Result
      Result Proceed to
      NG A
      OK (for 2GR-FE) B
      OK (for 2AZ-FE) C

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    A

  4. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU).


    NEXT

  5. ECU CODE REGISTRATION


    1. Register the ECU code.


    NEXT

  6. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.


    NEXT

  7. CHECK DTC OUTPUT


    1. Clear the DTCs Click here.

    2. Recheck for DTCs Click here.

      OK
      B279A output does not recur.
      Result
      Result Proceed to
      OK A
      NG (for 2GR-FE) B
      NG (for 2AZ-FE) C

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    A

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