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 No. 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

A0161HQE02

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.

      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

    A

    GO TO DTC CHART Click here

    B

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


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

    2. Disconnect the ECM connector.

      A0162YBE06

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J69-6 (EFIO) - A6-31 (IMI) Always Below 1 Ω
      J69-6 (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
      J69-6 (EFIO) - Body ground Always Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK ECM (INPUT)


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

    2. Reconnect the ECM connector.

    3. Measure the waveform.

      A015ZB6E01
      Waveform (Reference)
      Item Content
      Terminal No. (Symbols) A6-31 (IMI) - E6-1 (E1)
      Tool Setting 10 V/DIV., 100 msec./DIV.
      Condition Engine switch on (IG)
      OK
      Waveform is output normally (see illustration).

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU) Click here

    OK

    REPLACE ECM Click here

  4. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


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


    NEXT

  5. REGISTER ECU CODE


    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.

      OK
      B279A output does not recur.

    NG

    REPLACE ECM Click here

    OK

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