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

A01IPTNE01

INSPECTION PROCEDURE

Note

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

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. A01IPSGE10
      Text in Illustration
      *1 for AD Series Engine
      *2 for ZR Series Engine
      *3

      Front view of wire harness connector

      (to ID Code Box)
      *4

      Front view of wire harness connector

      (to ECM)

      Disconnect the H35 box connector.

    2. Disconnect the A51 ECM connector.

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

      Standard Resistance
      for AD Series Engine
      Tester Connection Condition Specified Condition
      H35-6 (EFIO) - A51-16 (IMI) Always Below 1 Ω
      H35-6 (EFIO) or A51-16 (IMI) - Body ground Always 10 kΩ or higher
      for ZR Series Engine
      Tester Connection Condition Specified Condition
      H35-6 (EFIO) - A51-11 (IMI) Always Below 1 Ω
      H35-6 (EFIO) or A51-11 (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.

      A01IPFDE05
      Measurement Condition
      Item Content
      Tester Connection H35-6 (EFIO) - H35-8 (GND)
      Tool Setting 10 V/DIV., 100 msec./DIV.
      Condition Engine switch on (IG)
      OK
      Waveform is output normally (refer to illustration).
      Result
      Result Proceed to
      OK (for 1AD-FTV) A
      OK (for 2AD-FHV) B
      OK (for 1ZR-FAE) C
      OK (for 2ZR-FAE) D
      NG E

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    D

    REPLACE ECM Click here

    E

    CHECK ID CODE BOX (POWER SOURCE AND BODY GROUND) Click here

    A

    REPLACE ECM Click here

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

    A01IRAXE02
    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
      H35-1 (+B) - H35-8 (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.

      Result
      Result Proceed to
      DTC B279A is not output A
      DTC B279A is output (for 1AD-FTV) B
      DTC B279A is output (for 2AD-FHV) C
      DTC B279A is output (for 1ZR-FAE) D
      DTC B279A is output (for 2ZR-FAE) E

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    D

    REPLACE ECM Click here

    E

    REPLACE ECM Click here

    A

    END (ID CODE BOX IS DEFECTIVE)