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 high output (e. g. shorted to +B), the power management control ECU stores this DTC.

DTC No. DTC Detection Condition Trouble Area
B279A When the communication line (EFIO - IMI) between power management control ECU and ID code box (immobiliser code ECU) is stuck high output.

  • Wire harness or connector

  • Power management control ECU

  • ID code box (Immobiliser code ECU)

WIRING DIAGRAM

A003ZWWE72

INSPECTION PROCEDURE

Note

If the ID code box (immobiliser code ECU) is replaced, refer to the Service Bulletin.

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 - POWER MANAGEMENT CONTROL ECU)


    1. Disconnect the L10 ID code box (immobiliser code ECU) connector.

    2. Disconnect the L6 power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L10-6 (EFIO) - L6-21 (IMI) Always Below 1 Ω
      L6-21 (IMI) - Body ground Always 10 kΩ or higher
      Standard Voltage
      Tester Connection Condition Specified Condition
      L6-21 (IMI) - 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 L10 ID code box (immobiliser code ECU) connector.

    2. A00427FE10
      Text in Illustration
      *1 GND
      *2 HIGH
      *3 LOW
      *a

      Component with harness connected

      (ID Code Box (Immobiliser Code ECU))

      Reconnect the L6 power management control ECU connector.

    3. Using an oscilloscope, check the waveform.

      Waveform (Reference)
      Item Content
      Terminal No. (Symbol) L10-6 (EFIO) - L10-8 (GND)
      Tool Setting 5 V/DIV., 50 msec./DIV.
      Condition Power switch on (IG)
      OK
      Waveform is output normally (see illustration).

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU) Click here

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  4. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


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

      Tech Tips

      refer to the Service Bulletin.


    NEXT

  5. ECU CODE REGISTRATION


    1. Register the ECU code.

      Tech Tips

      refer to the Service Bulletin.


    NEXT

  6. ECU COMMUNICATION ID REGISTRATION


    1. Register the ECU communication ID.

      Tech Tips

      refer to the Service Bulletin.


    NEXT

  7. CHECK DTC OUTPUT


    1. Clear the DTCs Click here.

    2. Recheck for DTCs Click here.

      OK
      DTC B279A is not output.

    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    OK

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