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 (HV CPU) stores this DTC.

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

  • Wire harness or connector

  • ID code box (Immobiliser code ECU)

  • Power management control ECU (HV CPU)

WIRING DIAGRAM

A01NCRZE11

INSPECTION PROCEDURE

Note

If the ID code box (immobiliser code ECU) is replaced, register the ECU code and 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 - POWER MANAGEMENT CONTROL ECU (HV CPU))


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

    2. A01NG2IE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ID Code Box (Immobiliser Code ECU))
      *2

      Front view of wire harness connector

      (to Power Management Control ECU (HV CPU))

      Disconnect the power management control ECU (HV CPU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F45-6 (EFIO) - F98-21 (IMI) Always Below 1 Ω
      F98-21 (IMI) - Body ground Always 10 kΩ or higher
      Standard Voltage
      Tester Connection Condition Specified Condition
      F98-21 (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 ID code box (immobiliser code ECU) connector.

    2. A01NGYJE02
      Text in Illustration
      *1

      Component with harness connected

      (ID Code Box (Immobiliser Code ECU))

      Reconnect the power management control ECU (HV CPU) connector.

    3. Using an oscilloscope, check the waveform.

      Waveform (Reference)
      Item Content
      Terminal No. (Symbol) F45-6 (EFIO) - F45-8 (GND)
      Tool Setting 5 V/DIV., 100 msec./DIV.
      Condition Power switch on (IG)
      OK
      Waveform is output normally (see illustration).
      Result
      Result Proceed to
      NG A
      OK (for LHD) B
      OK (for RHD) C

    B

    REPLACE POWER MANAGEMENT CONTROL ECU (HV CPU) (for LHD) Click here

    C

    REPLACE POWER MANAGEMENT CONTROL ECU (HV CPU) (for RHD) 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. CHECK DTC OUTPUT


    1. Clear the DTCs Click here.

    2. Recheck for DTCs Click here.

      OK
      DTC B279A is not output.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE POWER MANAGEMENT CONTROL ECU (HV CPU) (for LHD) Click here

    C

    REPLACE POWER MANAGEMENT CONTROL ECU (HV CPU) (for RHD) Click here

    A

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