SMART ENTRY AND START SYSTEM(for Start Function), 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 certification ECU (smart key ECU assembly), 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 of the following conditions is met (1 trip detection logic*1):


  • A malfunction is detected in the communication or communication lines between the ECM and certification ECU (smart key ECU assembly).

  • The communication ID codes of the ECM and certification ECU (smart key ECU assembly) do not match.

  • Certification ECU (smart key ECU assembly)

  • 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*1):


  • A malfunction is detected in the communication or communication lines between the ECM and certification ECU (smart key ECU assembly).

  • The communication ID codes of the ECM and certification ECU (smart key ECU assembly) do not match.

  • Certification ECU (smart key ECU assembly)

  • 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).

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

B006ZGTE08

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.

  • The smart entry and start system (for Start Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart entry and start system (for Start Function) after confirming that the communication systems are functioning properly.

    Click here

  • Before replacing the ECM or certification ECU (smart key ECU assembly), 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. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (TERMINAL EFII)


    1. Using an oscilloscope, check the waveform.

      B00705KC01
      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      		 *b Waveform
      *c Approximately 160 ms. *d Approximately 270 ms.
      OK
      Tester Connection Condition Tool Setting Specified Condition
      A13-3 (EFII) - Body ground Engine switch on (IG) 2 V/DIV., 500 ms./DIV.

      Pulse generation

      (See waveform)
      Result
      Result Proceed to
      Normal waveform A
      Terminal EFII stuck low (2.4 V or less) B
      Waveform not output, or has abnormal wavelength or shape C

    B

    CHECK ECM Click here

    C

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

    A

  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (TERMINAL EFIO)


    1. Using an oscilloscope, check the waveform.

      B0071TZC02
      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      		 *b Waveform
      *c Approximately 160 ms. *d Approximately 270 ms.
      OK
      Tester Connection Condition Tool Setting Specified Condition
      A13-4 (EFIO) - Body ground Engine switch turned on (IG) using registered electrical key transmitter sub-assembly 2 V/DIV., 500 ms./DIV.

      Pulse generation

      (See waveform)
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

  4. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID code.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK WHETHER ENGINE STARTS


    1. Using an electrical key transmitter sub-assembly which is registered to the vehicle, turn the engine switch on (IG).

    2. Check that the engine starts 5 seconds after the engine switch turned on (IG).

      OK
      Engine starts normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED)

    NG

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

  6. CHECK ECM


    1. Disconnect the A24*1, A23*2 or A22*3 ECM connector.


      • *1: for A25A-FKS

      • *2: for 2GR-FKS

      • *3: for 2AR-FE

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

      Standard Voltage
      for A25A-FKS
      Tester Connection Condition Specified Condition
      A24-25 (IMO) - Body ground Engine switch turned on (IG) using registered electrical key transmitter sub-assembly Terminal IMO stuck low (2.4 V or less)
      Terminal IMO stuck high (12 V) or abnormal waveform
      for 2GR-FKS
      Tester Connection Condition Specified Condition
      A23-45 (IMO) - Body ground Engine switch turned on (IG) using registered electrical key transmitter sub-assembly Terminal IMO stuck low (2.4 V or less)
      Terminal IMO stuck high (12 V) or abnormal waveform
      for 2AR-FE
      Tester Connection Condition Specified Condition
      A22-45 (IMO) - Body ground Engine switch turned on (IG) using registered electrical key transmitter sub-assembly Terminal IMO stuck low (2.4 V or less)
      Terminal IMO stuck high (12 V) or abnormal waveform
      Result
      Result Proceed to
      Terminal IMO stuck low (2.4 V or less) A
      Terminal IMO stuck high (12 V) or abnormal waveform B

    B

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

    A

  7. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ECM)


    1. Disconnect the A13 certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance
      for A25A-FKS
      Tester Connection Condition Specified Condition
      A13-3 (EFII) - A24-25 (IMO) Always Below 1 Ω
      A13-3 (EFII) or A24-25 (IMO) - Other terminals and body ground Always 10 kΩ or higher
      for 2GR-FKS
      Tester Connection Condition Specified Condition
      A13-3 (EFII) - A23-45 (IMO) Always Below 1 Ω
      A13-3 (EFII) or A23-45 (IMO) - Other terminals and body ground Always 10 kΩ or higher
      for 2AR-FE
      Tester Connection Condition Specified Condition
      A13-3 (EFII) - A22-45 (IMO) Always Below 1 Ω
      A13-3 (EFII) or A22-45 (IMO) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR