ENGINE 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 output (e.g. shorted to +B), the ECM stores this DTC.

DTC No. DTC Detection Condition Trouble Area
B279A Communication line (EFIO-IMI) between the ECM and transponder key ECU assembly is stuck high output.

  • Wire harness or connector

  • Transponder key ECU assembly

  • ECM

WIRING DIAGRAM

A01EMPAE76

INSPECTION PROCEDURE

Note


  • If the transponder key ECU assembly is replaced, register the key and ECU communication ID (Refer to Service Bulletin).

  • If the ECM is replaced, register the ECU communication ID (Refer to Service Bulletin).

PROCEDURE


  1. CHECK DTC OUTPUT


    1. 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 DTC CHART Click here

    A

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


    1. Disconnect the transponder key ECU assembly connector.

    2. A01EJUXE06
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Transponder Key ECU Assembly)
      *2

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D22-13 (EFIO) - A49-11 (IMI) Always Below 1 Ω
      D22-13 (EFIO) - Body ground Always 10 kΩ or higher
      A49-11 (IMI) - Body ground Always 10 kΩ or higher
      Standard Voltage
      Tester Connection Condition Specified Condition
      D22-13 (EFIO) - Body ground Always Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK TRANSPONDER KEY ECU ASSEMBLY (OUTPUT)


    1. Reconnect the transponder key ECU assembly connector.

    2. Reconnect the ECM connector.

    3. A01ELXVE01
      Text in Illustration
      *1

      Component with harness connected

      (Transponder Key ECU Assembly)

      Using an oscilloscope, check the waveform.

      Waveform 1 (Reference)
      Item Content
      Terminal No. (Symbols) D22-13 (EFIO) - D22-16 (GND)
      Tool Setting 2 V/DIV., 1 s./DIV.
      Condition Ignition switch ON

    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY Click here

    OK

    REPLACE ECM Click here

  4. REPLACE TRANSPONDER KEY ECU ASSEMBLY


    1. Replace the transponder key ECU assembly.

      Tech Tips

      Refer to Service Bulletin.


    NEXT

  5. REGISTER KEY


    1. Register the key.

      Tech Tips

      Refer to Service Bulletin.


    NEXT

  6. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.


    NEXT

  7. CHECK DTC OUTPUT


    1. Clear the DTCs Click here.

    2. Recheck for DTCs Click here.

      OK
      DTC B279A is not output.

    NG

    REPLACE ECM Click here

    OK

    END (TRANSPONDER KEY ECU WAS DEFECTIVE)