IMMOBILISER SYSTEM(w/ Smart Entry and Start System), Diagnostic DTC:B279A, B279A12

DTC Code DTC Name
B279A Theft Deterrent System Communication Line High Fixation
B279A12 Engine Immobiliser System Circuit Short to Battery

DESCRIPTION

When the communication line (IMI - EFIO) between the ECM and ID code box (immobiliser code ECU)*2 or certification ECU (smart key ECU assembly)*3 is stuck high, the ECM stores this DTC.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B279A Theft Deterrent System Communication Line High Fixation The communication line (IMI - EFIO) between the ECM and ID code box (immobiliser code ECU)*2 or certification ECU (smart key ECU assembly)*3 is stuck high. (1 trip detection logic*1)

  • ID code box (immobiliser code ECU)*2

  • Certification ECU (smart key ECU assembly)*3

  • ECM

  • Wire harness or connector

DTC output confirmation operation:


  • Turn the engine switch on (IG) and wait 6 seconds.
B279A12 Engine Immobiliser System Circuit Short to Battery The communication line (IMI - EFIO) between the ECM and ID code box (immobiliser code ECU)*2 or certification ECU (smart key ECU assembly)*3 is stuck high. (1 trip detection logic*1)

  • ID code box (immobiliser code ECU)*2

  • Certification ECU (smart key ECU assembly)*3

  • ECM

  • Wire harness or connector

DTC output confirmation operation:


  • Turn the engine switch on (IG) and wait 6 seconds.

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
Engine cannot be started Engine cannot be started
Related Data List and Active Test
DTC No. Data List and Active Test

  • B279A*1

  • B279A12*2

 -

WIRING DIAGRAM


  1. w/ Rear Seat Heater

    A00287SE30

  2. w/o Rear Seat Heater

    A00287SE31
    *1 Certification ECU (Smart Key ECU Assembly)

CAUTION / NOTICE / HINT

Note


  • When using the GTS with the engine switch off, connect the GTS to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Entry&Start(CAN). While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.

  • Before replacing the ECM, ID code box (immobiliser code ECU)*1 or certification ECU (smart key ECU assembly)*2, refer to Service Bulletin.


    • *1: w/ Rear Seat Heater

    • *2: w/o Rear Seat Heater

  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

Tech Tips

When DTC B279A*1 or B279A12*2 and a certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.


PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine and ECT > Clear DTCs
      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Turn the engine switch on (IG) and wait 10 seconds.

    2. Check for DTCs.


      Powertrain > Engine and ECT > Trouble Codes
      Powertrain > Engine > Trouble Codes

      Tech Tips

      If DTCs other than DTC B279A*1 or B279A12*2 are output, troubleshoot those DTCs first.

      Result
      Result Proceed to
      DTC B279A*1 or B279A12*2 is output A
      DTC B279A*1 or B279A12*2 and other DTCs are output B

      • *1: for 1AR-FE

      • *2: for 2GR-FKS


    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  3. CHECK CONNECTION OF CONNECTOR


    1. Turn the engine switch off.

    2. Check that the connectors are properly connected to the ECM and ID code box (immobiliser code ECU)*1 or certification ECU (smart key ECU assembly)*2.


      • *1: w/ Rear Seat Heater

      • *2: w/o Rear Seat Heater

      OK
      Connectors are properly connected.
      Result
      Result Proceed to
      OK (w/ Rear Seat Heater) A
      OK (w/o Rear Seat Heater) B
      NG C

    B

    CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ECM) Click here

    C

    CONNECT CONNECTORS PROPERLY

    A

  4. CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM)


    1. Disconnect the F67 ID code box (immobiliser code ECU) connector.

    2. Disconnect the A43 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F67-4 (EFIO) - A43-59 (IMI)*2 Always Below 1 Ω
      F67-4 (EFIO) - A43-28 (IMI)*1 Always Below 1 Ω
      F67-4 (EFIO) or A43-59 (IMI) - Body ground*2 Always 10 kΩ or higher
      F67-4 (EFIO) or A43-28 (IMI) - Body ground*1 Always 10 kΩ or higher

      • *1: for 1AR-FE

      • *2: for 2GR-FKS

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      A43-59 (IMI) - Body ground*2 Always 11 to 14 V
      A43-28 (IMI) - Body ground*1 Always 11 to 14 V

      • *1: for 1AR-FE

      • *2: for 2GR-FKS

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU) with a new one.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 8 Click here

  6. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ECM)


    1. Disconnect the F10 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the A43 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F10-6 (EFIO) - A43-59 (IMI) Always Below 1 Ω
      F10-6 (EFIO) or A43-59 (IMI) - 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
      A43-59 (IMI) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. Replace the certification ECU (smart key ECU assembly) with a new one.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  8. REGISTER RECOGNITION CODE


    1. Register the recognition codes in the ECUs.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  9. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  10. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  11. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Powertrain > Engine > Trouble Codes
      OK
      B279A12 is not output.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE ECM Click here