IMMOBILISER 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

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
B2799 Engine Immobiliser System Malfunction

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

  • Wire 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).
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

  • Wire harness or connector

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

  • B2799*1

  • B279986*2

 -

WIRING DIAGRAM


  1. w/o Blocking System

    B003WD4E32

  2. w/ Blocking System

    B003U10E16
    *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 B2799*1 or B279986*2 and the certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.


  • *1: for 2GR-FSE

  • *2: for 8AR-FTS

PROCEDURE


  1. SYSTEM CHECK


    1. Check the vehicle specification.

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

    B

    CHECK HARNESS AND CONNECTOR (ECM - TELEPHONE TRANSCEIVER ASSEMBLY) 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
      B2799*1 or B279986*2 is not output.

      • *1: for 2GR-FSE

      • *2: for 8AR-FTS

      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 K83 ID code box (immobiliser code ECU) connector.

    2. Disconnect the A77*1 or A91*2 ECM connector.


      • *1: for 2GR-FSE

      • *2: for 8AR-FTS

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

      Standard Resistance
      for 2GR-FSE
      Tester Connection Condition Specified Condition
      K83-4 (EFIO) - A77-31 (IMI) Always Below 1 Ω
      K83-3 (EFII) - A77-30 (IMO) Always Below 1 Ω
      K83-4 (EFIO) or A77-31 (IMI) - Body ground Always 10 kΩ or higher
      K83-3 (EFII) or A77-30 (IMO) - Body ground Always 10 kΩ or higher
      for 8AR-FTS
      Tester Connection Condition Specified Condition
      K83-4 (EFIO) - A91-31 (IMI) Always Below 1 Ω
      K83-3 (EFII) - A91-45 (IMO) Always Below 1 Ω
      K83-4 (EFIO) or A91-31 (IMI) - Body ground Always 10 kΩ or higher
      K83-3 (EFII) or A91-45 (IMO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 15 Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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


    1. Disconnect the A91 ECM connector.

    2. Disconnect the K76 telephone transceiver assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A91-45 (IMO) - K76-7 (BLK2) Always Below 1 Ω
      A91-28 (IMI) - K76-8 (BLK3) Always Below 1 Ω
      A91-45 (IMO) or K76-7 (BLK2) - Body ground Always 10 kΩ or higher
      A91-28 (IMI) or K76-8 (BLK3) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the K83 ID code box (immobiliser code ECU) connector.

    2. Disconnect the K76 telephone transceiver assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K83-3 (EFII) - K76-1 (BLK1) Always Below 1 Ω
      K83-4 (EFIO) - K76-2 (BLK4) Always Below 1 Ω
      K83-3 (EFII) or K76-1 (BLK1) - Body ground Always 10 kΩ or higher
      K83-4 (EFIO) or K76-2 (BLK4) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  9. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK FOR DTC


    1. Check for DTCs.


      Powertrain > Engine > Trouble Codes

      Tech Tips

      Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

      Result
      Result Proceed to
      B279986 is not output A
      B279986 is output B
      Other DTCs are output C

    A

    END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

    C

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    B

  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. Check for DTCs.


      Powertrain > Engine > Trouble Codes

      Tech Tips

      Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

      OK
      B279986 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (TELEPHONE TRANSCEIVER ASSEMBLY WAS DEFECTIVE)

    NG

  15. REPLACE ECM


    1. Temporarily replace the ECM with a new one.

      for 2GR-FSE: Click here

      for 8AR-FTS: Click here

      Result
      Proceed to
      NEXT

    NEXT

  16. CLEAR DTC


    1. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  17. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


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

    OK

    END (ECM WAS DEFECTIVE)

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)