IMMOBILISER SYSTEM, Diagnostic DTC:B279986

DTC Code DTC Name
B279986 Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid

DESCRIPTION

When there is a communication malfunction between the ECM and ID code box (immobiliser code ECU), or when the communication ID codes do not match, the ECM stores this DTC.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B279986 Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid

Either condition is met (1 trip detection logic*1):


  • A malfunction in the communication or communication lines between the ECM and ID code box (immobiliser code ECU).

  • A matching communication code cannot be verified during communication between the ECM and ID code box (immobiliser code ECU).

  • ID code box (immobiliser code ECU)

  • ECM

  • Harness or connector

  • Telephone transceiver assembly*2

DTC output confirmation operation (Either condition is met):


  • Within 10 seconds of an engine start operation being performed (with the shift lever in P and the brake pedal depressed, the engine switch is pressed while the key is being carried). If there is a malfunction, the engine stops (communication begins within 3 seconds of the engine start operation being performed, and DTCs are stored after 6 seconds).

  • 10 seconds after the engine switch is turned on (IG) after reconnecting the cable to the negative (-) battery terminal (communication begins within 3 seconds of the engine switch being turned on (IG), and DTCs are stored after 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 -
Related Data List and Active Test
DTC No. Data List and Active Test
B279986 -

WIRING DIAGRAM


  1. w/o Blocking System

    B008GPBE22
    *a ID Code Box (Immobiliser Code ECU)

  2. w/ Blocking System

    B008HO1E14
    *a Telephone Transceiver Assembly
    *b ID Code Box (Immobiliser Code ECU)

CAUTION / NOTICE / HINT

Note


  • When using the GTS with the engine switch off, connect the GTS to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Entry&Start(CAN). While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.

  • Before replacing the ECM, telephone transceiver assembly* or ID code box (immobiliser code ECU), refer to Service Bulletin.

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

  • When the telephone transceiver assembly is replaced, it is necessary to set the contract mode.*


  • *: w/ Blocking System

Tech Tips

When DTC B279986 and the certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.

PROCEDURE


  1. SYSTEM CHECK


    1. Check the vehicle specification.

      Result
      Result Proceed to
      w/o Blocking System A
      w/ Blocking System B

    B

    GO TO STEP 9 Click here

    A

  2. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  3. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  4. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Powertrain > Engine > Trouble Codes
      OK
      B279986 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

    NG

  5. CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM)


    1. Disconnect the I26 ID code box (immobiliser code ECU) connector.

    2. Disconnect the A35 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I26-4 (EFIO) - A35-28 (IMI) Always Below 1 Ω
      I26-3 (EFII) - A35-45 (IMO) Always Below 1 Ω
      I26-4 (EFIO) or A35-28 (IMI) - Body ground Always 10 kΩ or higher
      I26-3 (EFII) or A35-45 (IMO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  7. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  8. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Powertrain > Engine > Trouble Codes
      OK
      B279986 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

    NG

  9. CHECK HARNESS AND CONNECTOR (ECM - TELEPHONE TRANSCEIVER ASSEMBLY)


    1. Disconnect the A35 ECM connector.

    2. Disconnect the I131 telephone transceiver assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A35-45 (IMO) - I131-7 (BLK2) Always Below 1 Ω
      A35-28 (IMI) - I131-8 (BLK3) Always Below 1 Ω
      A35-45 (IMO) or I131-7 (BLK2) - Body ground Always 10 kΩ or higher
      A35-28 (IMI) or I131-8 (BLK3) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - TELEPHONE TRANSCEIVER ASSEMBLY)


    1. Disconnect the I26 ID code box (immobiliser code ECU) connector.

    2. Disconnect the I131 telephone transceiver assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I26-3 (EFII) - I131-1 (BLK1) Always Below 1 Ω
      I26-4 (EFIO) - I131-2 (BLK4) Always Below 1 Ω
      I26-3 (EFII) or I131-1 (BLK1) - Body ground Always 10 kΩ or higher
      I26-4 (EFIO) or I131-2 (BLK4) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. REPLACE TELEPHONE TRANSCEIVER ASSEMBLY


    1. Temporarily replace the telephone transceiver assembly with a new or known good one.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  12. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  13. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  14. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Powertrain > Engine > Trouble Codes
      OK
      B279986 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (TELEPHONE TRANSCEIVER ASSEMBLY WAS DEFECTIVE)

    NG

  15. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU) with a new one.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  16. REGISTER RECOGNITION CODE


    1. Register the recognition codes in the ECUs.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  17. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  18. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  19. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Powertrain > Engine > Trouble Codes
      OK
      B279986 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (ID CODE BOX (IMMOBILISER CODE ECU) WAS DEFECTIVE)

    NG

    REPLACE ECM Click here