ENGINE IMMOBILISER SYSTEM(w/ 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 ID code box 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 the ID code box is stuck on HI output.

  • Harness or connector

  • ID code box

  • ECM

WIRING DIAGRAM

A004RR9E06
*a from ECU-B2 Fuse
*b ID Code Box

CAUTION / NOTICE / HINT

Tech Tips

When the ID code box is replaced, reregister the ECU - ECM communication ID.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

      If 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 DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  3. CHECK HARNESS AND CONNECTOR (ID CODE BOX - ECM)


    1. A004OQZE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ID Code Box)
      *2

      Front view of wire harness connector

      (to ECM)

      Disconnect the D26 box connector.

    2. Disconnect the A40 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D26-6 (EFIO) - A40-16 (IMI) Always Below 1 Ω
      D26-6 (EFIO) or A40-16 (IMI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK ID CODE BOX (OUTPUT)

    A004NB2E01
    *1 Component with harness connected: (ID Code Box)
    *2 LOW

    1. Using an oscilloscope, check the waveform.

      Measurement Condition
      Item Content
      Tester Connection D26-6 (EFIO) - D26-8 (GND)
      Tool Setting 10 V/DIV., 100 msec./DIV.
      Condition Engine switch on (IG)
      OK
      Waveform is output normally (see illustration).
      Result
      Result Proceed to
      OK (for 1AD-FTV) A
      OK (for 2AD-FHV) B
      OK (for 2AD-FTV) C
      NG D

    A

    REPLACE ECM Click here

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    D

  5. CHECK ID CODE BOX (POWER SOURCE AND BODY GROUND)

    A004QT6E02
    Text in Illustration
    *1

    Component with harness connected

    (ID Code Box)

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

      Standard Voltage
      Tester Connector Condition Specified Condition
      D26-1 (+B) - D26-8 (GND) Always 11 to 14 V

    OK

    REPLACE ID CODE BOX

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR