ENGINE IMMOBILISER 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 ID code box is stuck on HI output, the ECM outputs this DTC.

DTC Code DTC Detection Condition Trouble Area
B279A The communication line (EFIO-IMI) between the ECM and ID code box is stuck on HI output (1 trip detection logic*1).

  • Harness or connector

  • ID code box

  • ECM

  • Telephone transceiver assembly*2

WIRING DIAGRAM

A001B0NE03
w/o Blocking System
*a from Battery
*b SECURITY
*c ID Code Box
A0019N9E03
w/ Blocking System
*a from Battery
*b SECURITY
*c Telephone Transceiver Assembly
*d ID Code Box

CAUTION / NOTICE / HINT

Note


  • When replacing the ID code box, ECM or telephone transceiver assembly (w/ Blocking System), refer to the Service Bulletin.

  • After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

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

Tech Tips

w/ Blocking System:

After troubleshooting for this DTC, make sure B279A is not output. If output, troubleshoot the blocking system DTCs next.

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
      No DTC is output A
      DTC B279A and other DTCs are output B
      DTC B279A is output C

      Tech Tips

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


    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    Go to DIAGNOSTIC TROUBLE CODE CHART Click here

    C

  3. CHECK HARNESS AND CONNECTOR (SFI COMMUNICATION LINE)


    1. Disconnect the L32 ID code box connector.

    2. Disconnect the A13 ECM connector.

    3. w/ Blocking System:


      1. Disconnect the L180 telephone transceiver assembly connector.

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

      Standard Resistance
      w/o Blocking System
      Tester Connection Condition Specified Condition
      L32-6 (EFIO) - A13-31 (IMI) Always Below 1 Ω
      L32-6 (EFIO) - Body ground Always 10 kΩ or higher
      w/ Blocking System
      Tester Connection Condition Specified Condition
      L32-6 (EFIO) - L180-2 (BLK4) Always Below 1 Ω
      L180-8 (BLK3) - A13-31 (IMI) Always Below 1 Ω
      L32-6 (EFIO) - Body ground Always 10 kΩ or higher
      A13-31 (IMI) - Body ground Always 10 kΩ or higher

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

      Standard Voltage
      w/o Blocking System
      Tester Connection Condition Specified Condition
      L32-6 (EFIO) - Body ground Always Below 1 V
      w/ Blocking System
      Tester Connection Condition Specified Condition
      L32-6 (EFIO) - Body ground Always Below 1 V
      A13-31 (IMI) - Body ground Always Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK ID CODE BOX (TERMINAL EFIO)


    1. Using an oscilloscope, check the waveform.

      A001DJJE02
      Text in Illustration
      *1 Waveform - -
      *a

      Component with harness connected

      (ECM)

      		 - -
      Measurement Condition
      Item Content
      Tester Connection A13-31 (IMI) - Body ground
      Tool Setting 10 V/DIV., 100 ms./DIV.
      Condition Within 3 seconds after starter operates and initial combustion occurs, or within 3 seconds after engine switch first turned to ON after battery disconnected and reconnected

      Tech Tips

      The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.

      OK
      Waveform is output normally (refer to illustration).

    OK

    REPLACE ID CODE BOX

    NG

  5. CHECK HARNESS AND CONNECTOR (ID CODE BOX - BATTERY AND BODY GROUND)


    1. A0018Y8E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ID Code Box)

      Disconnect the L32 ID code box connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L32-8 (GND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L32-1 (+B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. REPLACE ECM


    1. Temporarily replace the ECM with a new one.



    NEXT

  7. REGISTER ECU 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 (w/o Blocking System) B
      NG (w/ Blocking System) C

    A

    END (ECM IS DEFECTIVE)

    B

    REPLACE ID CODE BOX

    C

  10. REPLACE ID CODE BOX


    1. Temporarily replace the ID code box with a new one (Refer to the service Bulletin).


    NEXT

  11. REGISTER ECU COMMUNICATION ID


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


    NEXT

  12. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  13. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B279A is not output.

    OK

    END (ID CODE BOX IS DEFECTIVE)

    NG

    REPLACE TELEPHONE TRANSCEIVER ASSEMBLY