IMMOBILISER SYSTEM(w/o Smart Entry and Start System), Diagnostic DTC:B279A, B279A12

DTC Code DTC Name
B279A Theft Deterrent System Communication Line High Fixation
B279A12 Engine Immobiliser System Circuit Short to Battery

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. Detection Item DTC Detection Condition Trouble Area Note
B279A Theft Deterrent System Communication Line High Fixation Communication line (EFIO-IMI) between the ECM and transponder key ECU assembly is stuck high.

  • Wire harness or connector

  • ECM

  • Transponder key ECU assembly

    DTC Output Confirmation Operation:

  • Turn the ignition switch to ON and wait 6 seconds.
B279A12 Engine Immobiliser System Circuit Short to Battery Communication line (EFIO-IMI) between the ECM and transponder key ECU assembly is stuck high.

  • Wire harness or connector

  • ECM

  • Transponder key ECU assembly

    DTC Output Confirmation Operation:

  • 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*1 -
B279A12*2

WIRING DIAGRAM

B0070WRE06

CAUTION / NOTICE / HINT

Note


  • If the transponder key ECU assembly or ECM is replaced, refer to Service Bulletin.

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

PROCEDURE


  1. 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.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK ECM


    1. Disconnect the K60 transponder key ECU assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K60-11 (EFIO) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - ECM) Click here

    OK

  3. CHECK TRANSPONDER KEY ECU ASSEMBLY (TERMINAL EFIO)


    1. Connect the K60 transponder key ECU assembly connector.

    2. Using an oscilloscope, check the waveform.

      B006X4CC02
      *a

      Component with harness connected

      (Transponder Key ECU Assembly)

      		 *b Waveform
      *c Approximately 160 ms. *d Approximately 270 ms.
      OK
      Tester Connection Condition Tool Setting Specified Condition
      K60-11 (EFIO) - Body ground Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal 2 V/DIV., 500 ms./DIV.

      Pulse generation

      (See waveform)
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM for 2AR-FE: Click here
    REPLACE ECM for A25A-FKS: Click here

    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

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


    1. Disconnect the A22*1 or A24*2 ECM connector.


      • *1: for 2AR-FE

      • *2: for A25A-FKS

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

      Standard Resistance
      for 2AR-FE
      Tester Connection Condition Specified Condition
      K60-11 (EFIO) - A22-28 (IMI) Always Below 1 Ω
      K60-11 (EFIO) or A22-28 (IMI) - Other terminals and body ground Always 10 kΩ or higher
      for A25A-FKS
      Tester Connection Condition Specified Condition
      K60-11 (EFIO) - A24-26 (IMI) Always Below 1 Ω
      K60-11 (EFIO) or A24-26 (IMI) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM for 2AR-FE: Click here
    REPLACE ECM for A25A-FKS: Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR