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 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.
Table 1. 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
Table 2. Related Data List and Active Test

DTC No.

Data List and Active Test

B279A

-

WIRING DIAGRAM

B388980E01

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. CLEAR DTC

    1. Clear the DTCs.

      1. for 1KR-FE

        Powertrain > Engine and ECT > Clear DTCs

      2. for 1PP

        Powertrain > Engine > Clear DTCs

    Result

    Proceed to

    NEXT
    NEXT

  2. CHECK FOR DTC

    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.

      1. for 1KR-FE

        Powertrain > Engine and ECT > Trouble Codes

      2. for 1PP

        Powertrain > Engine > Trouble Codes

    OK

    DTC B279A is not output.

    Result

    Result

    Proceed to

    B279A is not output

    A

    B279A is output

    B
    A

    USE SIMULATION METHOD TO CHECK

    Click hereClick here

    B

  3. 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

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

    1. Disconnect the E24 transponder key ECU assembly connector.

    2. Disconnect the A34*1 or B56*2 ECM connector.

      • *1: for 1KR-FE

      • *2: for 1PP

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      E24-13 (EFIO) - A34-42 (IMI)*1

      Always

      Below 1 Ω

      E24-13 (EFIO) - B56-19 (IMI)*2

      Always

      Below 1 Ω

      A34-42 (IMI) or E24-13 (EFIO) - Body ground*1

      Always

      10 kΩ or higher

      B56-19 (IMI) or E24-13 (EFIO) - Body ground*2

      Always

      10 kΩ or higher

      • *1: for 1KR-FE

      • *2: for 1PP

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE TRANSPONDER KEY ECU ASSEMBLY

    1. Replace the transponder key ECU assembly with a new one.

      Tip:

      Refer to Service Bulletin.

      Note:

      Key ID code registration is necessary when replacing the transponder key ECU assembly, refer to Service Bulletin.

    Result

    Proceed to

    NEXT
    NEXT

  6. CLEAR DTC

    1. Clear the DTCs.

      1. for 1KR-FE

        Powertrain > Engine and ECT > Clear DTCs

      2. for 1PP

        Powertrain > Engine > Clear DTCs

    Result

    Proceed to

    NEXT
    NEXT

  7. CHECK FOR DTC

    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.

      1. for 1KR-FE

        Powertrain > Engine and ECT > Trouble Codes

      2. for 1PP

        Powertrain > Engine > Trouble Codes

        OK

        DTC B279A is not output.

    Result

    Result

    Proceed to

    B279A is not output

    A

    B279A is output

    B
    A

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE ECM

    for 1KR-FE:Click here

    for 1PP:Click here