ENGINE IMMOBILISER SYSTEM (w/o 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 on HI output, the ECM stores this DTC.

DTC Code DTC Detection Condition Trouble Area
B279A The communication line (EFIO-IMI) between the ECM and transponder key ECU assembly is stuck on HI output for 6 seconds or more.

  • Harness or connector

  • Transponder key ECU assembly

  • ECM

WIRING DIAGRAM

A00O6EDE23

INSPECTION PROCEDURE

Note


  • When replacing the transponder key ECU assembly and/or ECM, refer to the Service Bulletin.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B279A is output A
      DTC B279A and other DTCs are output B

      Tech Tips

      If any DTCs other than B279A are output, troubleshoot those DTCs first.


    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    A

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


    1. Disconnect the G74 ECU connector.

    2. Disconnect the G60*1, G56*2 or G58*3 ECM connector.


      • *1: for 2TR-FE

      • *2: for 1GR-FE

      • *3: for 1KD-FTV

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

      Standard Resistance
      for 2TR-FE
      Tester Connection Condition Specified Condition
      G74-13 (EFIO) - G60-31 (IMI) Always Below 1 Ω
      G74-13 (EFIO) or G60-31 (IMI) - Body ground Always 10 kΩ or higher
      for 1GR-FE
      Tester Connection Condition Specified Condition
      G74-13 (EFIO) - G56-14 (IMI) Always Below 1 Ω
      G74-13 (EFIO) or G56-14 (IMI) - Body ground Always 10 kΩ or higher
      for 1KD-FTV
      Tester Connection Condition Specified Condition
      G74-13 (EFIO) - G58-28 (IMI) Always Below 1 Ω
      G74-13 (EFIO) or G58-28 (IMI) - Body ground Always 10 kΩ or higher

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

      Standard Voltage
      for 2TR-FE
      Tester Connection Condition Specified Condition
      G74-13 (EFIO) - Body ground Always Below 1 V
      G60-31 (IMI) - Body ground
      for 1GR-FE
      Tester Connection Condition Specified Condition
      G74-13 (EFIO) - Body ground Always Below 1 V
      G56-14 (IMI) - Body ground
      for 1KD-FTV
      Tester Connection Condition Specified Condition
      G74-13 (EFIO) - Body ground Always Below 1 V
      G58-28 (IMI) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK TRANSPONDER KEY ECU ASSEMBLY (OUTPUT)


    1. Using an oscilloscope, check the waveform.

      A00O7WVE07
      Text in Illustration
      *A for 2TR-FE *B for 1GR-FE
      *C for 1KD-FTV - -
      *a

      Component with harness connected

      (ECM)

      		 *b Waveform
      Measurement Condition
      Item Content
      Tester Connection

      G60-31 (IMI) - Body ground*1

      G56-14 (IMI) - Body ground*2

      G58-28 (IMI) - Body ground*3
      Tool Setting 10 V/DIV., 100 ms./DIV.
      Condition Ignition switch ON

      • *1: for 2TR-FE

      • *2: for 1GR-FE

      • *3: for 1KD-FTV

      OK
      Waveform is output normally (refer to illustration).

    NG

    CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY GROUND) Click here

    OK

    REPLACE ECM Click here

  5. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY GROUND)


    1. A00O8K7E13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Transponder Key ECU Assembly)

      Disconnect the G74 ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G74-1 (+B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G74-16 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. REPLACE TRANSPONDER KEY ECU ASSEMBLY


    1. Replace the transponder key ECU assembly (Refer to the Service Bulletin).


    NEXT

  7. REGISTER ECU - ECM COMMUNICATION ID


    1. Register the ECU - ECM communication ID (Refer to the Service Bulletin).


    NEXT

  8. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  9. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B279A is not output.
      Result
      Result Proceed to
      OK A
      NG (for 2TR-FE) B
      NG (for 1GR-FE) C
      NG (for 1KD-FTV) D

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    D

    REPLACE ECM Click here

    A

    END (TRANSPONDER KEY ECU IS DEFECTIVE)