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 certification ECU assembly (smart key ECU assembly)*1 or ID code box (immobiliser code ECU)*2 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 certification ECU assembly (smart key ECU assembly)*1 or ID code box (immobiliser code ECU)*2 is stuck high output.

  • Wire harness or connector

  • Power management control ECU (HV CPU)

  • Certification ECU (Smart key ECU assembly)*1

  • ID code box (Immobiliser code ECU)*2

  • Telephone transceiver assembly*3

WIRING DIAGRAM


  1. w/o Airbag Cut-off Switch

    A01JBGKE17

  2. w/ Airbag Cut-off Switch

    A01JCCHE03

INSPECTION PROCEDURE

Note


  • If the certification ECU (smart key ECU assembly) is replaced, register all the keys and ECU communication ID.*1

  • If the ID code box (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID.*2

  • When telephone transceiver is replaced, it is necessary to set the contract mode.*3


    • *1: w/o Airbag Cut-off Switch

    • *2: w/ Airbag Cut-off Switch

    • *3: w/ Blocking System

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. SYSTEM CHECK


    1. Check the vehicle specification.

      Result
      Result Proceed to
      w/ Blocking System A
      w/o Blocking System B

    B

    SYSTEM CHECK Click here

    A

  3. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - TELEPHONE TRANSCEIVER ASSEMBLY)


    1. Disconnect the telephone transceiver assembly connector.

    2. Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L156-8 (BLK3) - L6-21 (IMI) Always Below 1 Ω
      L6-21 (IMI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - TELEPHONE TRANSCEIVER ASSEMBLY)


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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L156-2 (BLK4) - L10-6 (EFIO) Always Below 1 Ω
      L10-6 (EFIO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE TELEPHONE TRANSCEIVER ASSEMBLY


    1. Temporarily replace the telephone transceiver assembly with a new or known good one.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  6. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  7. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  8. CHECK DTC OUTPUT


    1. Check for DTCs Click here.

      Tech Tips

      Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

      OK
      DTC B279A is not output.

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU) Click here

    OK

    END (TELEPHONE TRANSCEIVER ASSEMBLY WAS DEFECTIVE)

  9. SYSTEM CHECK


    1. Check the vehicle specification.

      Result
      Result Proceed to
      w/o Airbag Cut-off Switch A
      w/ Airbag Cut-off Switch B

    B

    CHECK HARNESS AND CONNECTOR (ID CODE BOX - POWER MANAGEMENT CONTROL ECU (HV CPU)) Click here

    A

  10. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - POWER MANAGEMENT CONTROL ECU (HV CPU))


    1. Disconnect the certification ECU (smart key ECU assembly) connector.

    2. A01J90HE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Certification ECU (Smart Key ECU Assembly))
      *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
      L62-35 (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

  11. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (WAVEFORM)


    1. Reconnect the certification ECU (smart key ECU assembly) connector.

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

      A01J96CE02

    3. Using an oscilloscope, check the waveform.

      Waveform (Reference)
      Item Content
      Terminal No. (Symbol) L62-35 (EFIO) - L62-15 (E)
      Tool Setting 5 V/DIV., 50 msec./DIV.
      Condition Power switch on (IG)
      OK
      Waveform is output normally (see illustration).
      Text in Illustration
      *1

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      		 *2 GND
      *3 HIGH *4 LOW

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Click here

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU (HV CPU) Click here

  12. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. Replace the certification ECU (smart key ECU assembly).

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  13. KEY REGISTRATION


    1. Register the key.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  14. ECU COMMUNICATION ID REGISTRATION


    1. Register the ECU communication ID.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  15. 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 (HV CPU) Click here

    OK

    END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

  16. CHECK HARNESS AND CONNECTOR (ID CODE BOX - POWER MANAGEMENT CONTROL ECU (HV CPU))


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

    2. A01J9U9E04
      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
      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

  17. CHECK ID CODE BOX (IMMOBILISER CODE ECU) (WAVEFORM)


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

    2. A01JBMTE01
      Text in Illustration
      *1

      Component with harness connected

      (ID Code Box (Immobiliser Code ECU))
      *2 GND
      *3 HIGH
      *4 LOW

      Reconnect the power management control ECU (HV CPU) 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 (HV CPU) Click here

  18. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


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

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  19. ECU CODE REGISTRATION


    1. Register the ECU code.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  20. ECU COMMUNICATION ID REGISTRATION


    1. Register the ECU communication ID.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  21. 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 (HV CPU) Click here

    OK

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