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

DTC Code DTC Name
B2799 Engine Immobiliser System Malfunction

DESCRIPTION

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


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

  • A matching communication code cannot be verified during communication between the ECM and certification ECU (smart key ECU assembly).

  • Certification ECU (smart key ECU assembly)

  • ECM

  • 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*2 and the brake pedal*2 or clutch pedal*3 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 -

WIRING DIAGRAM

B003MIZE07
*a Certification ECU (Smart Key ECU Assembly)

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 certification ECU (smart key ECU assembly) or ECM, refer to Service Bulletin.

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

Tech Tips

When DTC B2799 and a 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. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin

      Result
      Proceed to
      NEXT

    NEXT

  2. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  3. CHECK FOR DTC


    1. Start the engine.

    2. Check for DTCs.

      Click here


      Powertrain > Engine > Trouble Codes

      Tech Tips

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

      OK
      B2799 is not output.
      Result
      Result Proceed to
      OK A
      NG (DTC B2799 is output) B
      NG (Other DTCs are output) C

    A

    END (REGISTERED COMMUNICATION ID WAS DEFECTIVE)

    C

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    B

  4. INSPECT ECM (TERMINAL IMO)


    1. Using an oscilloscope, check the waveform.

      B003RNSC03
      *a

      Component with harness connected

      (ECM)

      		 *b Waveform
      Measurement Condition
      Item Content
      Tester Connection G50-17 (IMO) - Body ground
      Tool Setting 2 V/DIV., 500 ms./DIV.
      Condition Within 3 seconds after engine starts, or within 3 seconds after engine switch turned on (IG) after battery disconnected and reconnected
      OK
      The waveform is similar to that shown in the illustration.
      Result
      Result Proceed to
      Normal waveform A
      Terminal IMO stuck low (2.4 V or less) B
      Terminal IMO stuck high (12 V) or abnormal waveform C

    B

    INSPECT ECM (IMO TERMINAL VOLTAGE) Click here

    C

    GO TO STEP 8 Click here

    A

  5. INSPECT ECM (TERMINAL IMI)


    1. Using an oscilloscope, check the waveform.

      B003O1MC03
      *a

      Component with harness connected

      (ECM)

      		 *b Waveform
      Measurement Condition
      Item Content
      Tester Connection G50-16 (IMI) - Body ground
      Tool Setting 2 V/DIV., 500 ms./DIV.
      Condition Within 3 seconds after engine starts, or within 3 seconds after engine switch turned on (IG) after battery disconnected and reconnected
      OK
      The waveform is similar to that shown in the illustration.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 13 Click here

    OK

  6. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK WHETHER ENGINE STARTS


    1. Using a registered vehicle key, 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 (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

    NG

  8. REPLACE ECM


    1. Temporarily replace the ECM with a new one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  9. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK WHETHER ENGINE STARTS


    1. Using a registered vehicle key, 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 (ECM WAS DEFECTIVE)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

  11. INSPECT ECM (IMO TERMINAL VOLTAGE)


    1. Disconnect the ECM connector.

    2. Turn the engine switch on (IG).

    3. B003LIMC03
      *a

      Front view of wire harness connector

      (to ECM)

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

      Standard Voltage
      Tester Connection Condition Result
      G50-17 (IMO) - Body ground Engine switch on (IG) using registered key 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

    GO TO STEP 8 Click here

    A

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


    1. Disconnect the G16 and G17 certification ECU (smart key ECU assembly) connectors.

    2. Disconnect the G50 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G16-3 (EFII) - G50-17 (IMO) Always Below 1 Ω
      G17-35 (EFIO) - G50-16 (IMI) Always Below 1 Ω
      G50-17 (IMO) - Body ground Always 10 kΩ or higher
      G16-3 (EFII) - Body ground Always 10 kΩ or higher
      G50-16 (IMI) - Body ground Always 10 kΩ or higher
      G17-35 (EFIO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. Replace the certification ECU (smart key ECU assembly) with a new one.

      Tech Tips

      Refer to Service Bulletin.

      Note

      Recognition code registration is necessary when replacing the certification ECU (smart key ECU assembly).

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  14. CHECK WHETHER ENGINE STARTS


    1. Using a registered vehicle key, turn the engine switch on (IG).

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

      OK
      Engine starts normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

    NG

    REPLACE ECM Click here