IMMOBILISER SYSTEM(w/o Smart Entry and Start 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 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.
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 -

WIRING DIAGRAM

A00287SE03

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.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Powertrain > Engine > Trouble Codes
      OK
      DTC B279A is not output.
      Result
      Result Proceed to
      B279A is not output A
      B279A is output B

    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)


    1. Disconnect the F66 transponder 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
      F66-13 (EFIO) - A43-28 (IMI)*1 Always Below 1 Ω
      F66-13 (EFIO) - A43-31 (IMI)*2 Always Below 1 Ω
      A43-28 (IMI) or F66-13 (EFIO) - Body ground*1 Always 10 kΩ or higher
      A73-31 (IMI) or F66-13 (EFIO) - Body ground*2 Always 10 kΩ or higher

      • *1: for 1AR-FE

      • *2: for 2GR-FE

      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.

      Tech Tips

      Refer to Service Bulletin.

      Note

      Key ID code registration is necessary when replacing the transponder key ECU assembly, refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  6. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Powertrain > Engine > Trouble Codes
      OK
      DTC B279A is not output.
      Result
      Result Proceed to
      B279A is not output A
      B279A is output B

    A

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE ECM for 1AR-FE: Click here
    REPLACE ECM for 2GR-FE: Click here