ENGINE IMMOBILISER SYSTEM(w/ Entry and Start 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 is stuck on HI output, the ECM stores this DTC.

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

  • Harness or connector

  • ID code box

  • ECM

WIRING DIAGRAM

A002QPTE14

CAUTION / NOTICE / HINT

Note


  • When the ID code box is replaced, reregister the recognition codes and ECU communication ID.

  • for 1WW:

    After turning the engine switch off, make sure to wait at least 6 minutes before disconnecting the ECM connector or replacing the ECM.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

      If 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

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


    1. A002NUQE02
      Text in Illustration
      *1 for ZR Series Engine
      *2 for 1WW Engine
      *3

      Front view of wire harness connector

      (to ID Code Box)
      *4

      Front view of wire harness connector

      (to ECM)

      Disconnect the H111 box connector.

    2. Disconnect the A76 ECM connector.

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

      Standard Resistance
      for ZR Series Engine
      Tester Connection Condition Specified Condition
      H111-6 (EFIO) - A76-28 (IMI) Always Below 1 Ω
      H111-6 (EFIO) or A76-28 (IMI) - Body ground Always 10 kΩ or higher
      for 1WW Engine
      Tester Connection Condition Specified Condition
      H111-6 (EFIO) - A76-34 (IMI) Always Below 1 Ω
      H111-6 (EFIO) or A76-34 (IMI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK ID CODE BOX (OUTPUT)


    1. Using an oscilloscope, check the waveform.

      A002NB2E01
      *1 Component with harness connected: (ID Code Box)
      *2 LOW
      Measurement Condition
      Item Content
      Tester Connection H111-6 (EFIO) - H111-8 (GND)
      Tool Setting 10 V/DIV., 100 msec./DIV.
      Condition Engine switch on (IG)
      OK
      Waveform is output normally (refer to illustration).

      Tech Tips

      If replacing the ECM, refer to the procedures below.



    OK

    REPLACE ECM

    NG

  5. CHECK ID CODE BOX (POWER SOURCE AND BODY GROUND)

    A002QBAE02
    Text in Illustration
    *1

    Component with harness connected

    (ID Code Box)

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

      Standard Voltage
      Tester Connector Condition Specified Condition
      H111-1 (+B) - H111-8 (GND) Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. REPLACE ID CODE BOX


    1. Replace the ID code box.


    NEXT

  7. REGISTER RECOGNITION CODES


    1. Register the recognition codes in the ECUs.


    NEXT

  8. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.


    NEXT

  9. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  10. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B279A is not output.

      Tech Tips

      If replacing the ECM, refer to the procedures below.



    OK

    END (ID CODE BOX IS DEFECTIVE)

    NG

    REPLACE ECM