IMMOBILISER SYSTEM(w/o 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

If the communication line (EFIO-IMI) to the transponder key ECU assembly is stuck high (e.g. shorted to +B), the ECM stores this DTC.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B279A Theft Deterrent System Communication Line High Fixation Communication line (EFIO-IMI) between the ECM and transponder key ECU assembly is stuck high.

  • Wire harness or connector

  • ECM

  • Transponder key ECU assembly

    DTC Output Confirmation Operation:

  • Turn the ignition switch to ON and wait 6 seconds.
B279A12 Engine Immobiliser System Circuit Short to Battery Communication line (EFIO-IMI) between the ECM and transponder key ECU assembly is stuck high.

  • Wire harness or connector

  • ECM

  • Transponder key ECU assembly

    DTC Output Confirmation Operation:

  • Turn the ignition switch to ON 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 (initial ignition occurs and engine cranks, then ignition stops) Engine cannot be started
Related Data List and Active Test
DTC No. Data List and Active Test

  • B279A*1

  • B279A12*2

 -

*1: for 3ZR-FAE

*2: for 8NR-FTS

WIRING DIAGRAM

A001V86E06
*1 Transponder Key ECU Assembly

CAUTION / NOTICE / HINT

Note


  • If the transponder key ECU assembly or ECM is replaced, refer to Service Bulletin.

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

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.


      1. for 8NR-FTS:


        Powertrain > Engine > Clear DTCs

      2. for 3ZR-FAE:


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

    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs.


      1. for 8NR-FTS:


        Powertrain > Engine > Trouble Codes

      2. for 3ZR-FAE:


        Powertrain > Engine and ECT > Trouble Codes

      Tech Tips

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

      OK
      DTC B279A*1 or B279A12*2 is not output.
      Result
      Result Proceed to
      B279A*1 or B279A12*2 is not output A
      B279A*1 or B279A12*2 is output B

      *1: for 3ZR-FAE

      *2: for 8NR-FTS


    A

    USE SIMULATION METHOD TO CHECK Click here

    B

  3. CHECK CONNECTION OF CONNECTOR


    1. Check that the connectors are properly connected to the ECM and transponder key ECU assembly.

      OK
      Connectors are properly connected.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  4. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - ECM AND BODY GROUND)


    1. Disconnect the F22 transponder key ECU assembly connector

    2. Disconnect the A38 ECM connector

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F22-13 (EFIO) - A38-28 (IMI) Always Below 1 Ω
      F22-13 (EFIO) - Body ground Always 10 kΩ or higher
      A38-28 (IMI) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE TRANSPONDER KEY ECU ASSEMBLY


    1. Replace the transponder key ECU assembly with a new one.

      Result
      Proceed to
      NEXT

    NEXT

  6. CLEAR DTC


    1. Clear the DTCs.


      1. for 8NR-FTS:


        Powertrain > Engine > Clear DTCs

      2. for 3ZR-FAE:


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

    NEXT

  7. CHECK FOR DTC


    1. Check for DTCs.


      1. for 8NR-FTS:


        Powertrain > Engine > Trouble Codes

      2. for 3ZR-FAE:


        Powertrain > Engine and ECT > Trouble Codes

      Tech Tips

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

      OK
      DTC B279A*1 or B279A12*2 is not output.

      • *1: for 3ZR-FAE

        *2: for 8NR-FTS

      Result
      Result Proceed to
      B279A is not output A
      B279A is output (for 3ZR-FAE) B
      B279A12 is output (for 8NR-FTS) C

    A

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here