ENGINE IMMOBILISER SYSTEM (w/o Smart Key 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. DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B279A Communication line (EFIO-IMI) between the ECM and transponder key ECU assembly is stuck high.

  • Wire harness or connector

  • ECM

  • Transponder key ECU assembly

 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

A01HZT4E49

INSPECTION PROCEDURE

Note


  • If the transponder key ECU assembly or ECM is replaced, refer to Registration Click here.

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

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK DTC OUTPUT


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs Click here.

      OK
      DTC B279A is not output.
      Result
      Result Proceed to
      DTC B279A is output A
      DTC B279A is not output B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  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.

    NG

    CONNECT CONNECTORS PROPERLY

    OK

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


    1. Disconnect the I19 transponder key ECU assembly connector.

    2. Disconnect the A25 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I19-13 (EFIO) - A25-28 (IMI) Always Below 1 Ω
      I19-13 (EFIO) or A25-28 (IMI) - Body ground Always 10 kΩ or higher

    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 Click here.

      Note

      Key ID code registration is necessary when replacing the transponder key ECU assembly, refer to Registration Click here.


    NEXT

  6. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  7. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs Click here.

      OK
      DTC B279A is not output.
      Result
      Result Proceed to
      DTC B279A is not output A
      DTC B279A is output B

    B

    REPLACE ECM Click here

    A

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)