IMMOBILISER SYSTEM(w/ Entry and Start System), Diagnostic DTC:B2799, B279986

DTC Code DTC Name
B2799 Engine Immobiliser System Malfunction
B279986 Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid

DESCRIPTION

If 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
B2799 Engine Immobiliser System Malfunction

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


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

  • A malfunction in the 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

  • Wire harness or connector

DTC output confirmation operation (Perform either of the following):


  • Start the engine and wait for 10 seconds. If there is a malfunction, the engine will stop (communication begins within 3 seconds of the engine start operation being performed, and DTCs are stored after 6 seconds).

  • Connect the cable to the negative (-) battery terminal, start the engine and wait for 10 seconds (communication begins within 3 seconds of the engine switch being turned on (IG), and DTCs are stored after 6 seconds).
B279986 Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid

Either of the following conditions is met (1 trip detection logic*):


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

  • A malfunction in the 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

  • Wire harness or connector

DTC output confirmation operation (Perform either of the following):


  • Start the engine and wait for 10 seconds. If there is a malfunction, the engine will stop (communication begins within 3 seconds of the engine start operation being performed, and DTCs are stored after 6 seconds).

  • Connect the cable to the negative (-) battery terminal, start the engine and wait for 10 seconds (communication begins within 3 seconds of the engine switch being turned on (IG), and DTCs are stored after 6 seconds).

DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2 Pattern 3
Diagnosis Condition Engine start operation. ○ ○ ○
Malfunction Status A malfunction in the communication between the ECM and ID code box (immobiliser code ECU). ○ - -
A malfunction in the 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). - - ○
Detection Time - -
Number of Trips 1 trip 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

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*1

  • B2799*2

 -

WIRING DIAGRAM

A001YF1E20
*a 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 the vehicle type 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 or ID code box (immobiliser code ECU), refer to Service Bulletin.

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

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. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID code.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  2. CLEAR DTC


    1. for 8NR-FTS


      1. Clear the DTCs.

        Click here


        Powertrain > Engine > Clear DTCs

    2. for 3ZR-FAE


      1. Clear the DTCs.

        Click here


        Powertrain > Engine and ECT > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  3. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. for 8NR-FTS


      1. Check for DTCs.

        Click here


        Powertrain > Engine > Trouble Codes
        OK
        B279986 is not output.

    3. for 3ZR-FAE


      1. Check for DTCs.

        Click here


        Powertrain > Engine and ECT > Trouble Codes
        OK
        B2799 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

    NG

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


    1. Disconnect the F21 ID code box (immobiliser code ECU) connector.

    2. Disconnect the A38 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F21-4 (EFIO) - A38-28 (IMI) Always Below 1 Ω
      F21-3 (EFII) - A38-45 (IMO) Always Below 1 Ω
      F21-4 (EFIO) or A38-28 (IMI) - Body ground Always 10 kΩ or higher
      F21-3 (EFII) or A38-45 (IMO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. 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

  6. REGISTER RECOGNITION CODE


    1. Register the recognition codes in the ECUs.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  7. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  8. CHECK WHETHER ENGINE STARTS


    1. Check that the engine starts.

      OK
      Engine starts normally.
      Result
      Result Proceed to
      OK A
      NG (for 8NR-FTS) B
      NG (for 3ZR-FAE) C

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    A

  9. CLEAR DTC


    1. for 8NR-FTS


      1. Clear the DTCs.

        Click here


        Powertrain > Engine > Clear DTCs

    2. for 3ZR-FAE


      1. Clear the DTCs.

        Click here


        Powertrain > Engine and ECT > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. for 8NR-FTS


      1. Check for DTCs.

        Click here


        Powertrain > Engine > Trouble Codes
        OK
        B279986 is not output.

    3. for 3ZR-FAE


      1. Check for DTCs.

        Click here


        Powertrain > Engine and ECT > Trouble Codes
        OK
        B2799 is not output.
      Result
      Result Proceed to
      OK A
      NG (for 8NR-FTS) B
      NG (for 3ZR-FAE) C

    A

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

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here