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

DTC Code DTC Name
B2799 Engine Immobiliser System Malfunction

DESCRIPTION

The ECM stores this DTC when a communication line between the ECM and transponder key ECU assembly is malfunctioning or the communication ID of the ECM and transponder key ECU assembly do not match.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B2799 Engine Immobiliser System Malfunction

One of the following conditions is met:


  • Error in communication between ECM and transponder key ECU assembly.

  • Error in communication lines.

  • Communication ID is different during communication between ECM and transponder key ECU assembly.

  • Harness or connector

  • Transponder key ECU assembly

  • ECM

    DTC Output Confirmation Operation:

  • Start the engine and wait 10 seconds.

  • After disconnecting and reconnecting the cable to the negative (-) battery terminal, turn the ignition switch to ON and wait 10 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

B003Q3XE03
*1 Transponder Key ECU Assembly

CAUTION / NOTICE / HINT

Note


  • If the transponder key ECU assembly or ECM is replaced, refer to Service Bulletin.

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

Tech Tips

If transponder key ECU assembly DTCs are output simultaneously, troubleshoot the transponder key ECU assembly DTCs first.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Powertrain > Engine > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. 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 (B2799 is output) B
      NG (Other DTCs are output) C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    B

  3. INSPECT ECM (TERMINAL IMO)


    1. Using an oscilloscope, check the waveform.

      B003RNSC04
      *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 of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal
      OK
      Waveform is similar to that shown in the illustration.
      Result
      Result Proceed to
      OK A
      NG (Terminal IMO stuck low (2.4 V or less)) B
      NG (Terminal IMO stuck high (12 V) or abnormal waveform) C

    B

    INSPECT ECM (IMO TERMINAL VOLTAGE) Click here

    C

    GO TO STEP 7 Click here

    A

  4. INSPECT ECM (TERMINAL IMI)


    1. Using an oscilloscope, check the waveform.

      B003O1MC04
      *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 of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal
      OK
      Waveform is similar to that shown in the illustration.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 12 Click here

    OK

  5. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK WHETHER ENGINE STARTS


    1. Using a registered key, turn the ignition switch to ON.

    2. Check that the engine starts 5 seconds after the ignition switch was turned to ON.

      OK
      Engine starts normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

    NG

  7. REPLACE ECM


    1. Temporarily replace the ECM with a new one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  8. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK WHETHER ENGINE STARTS


    1. Using a registered key, turn the ignition switch to ON.

    2. Check that the engine starts 5 seconds after the ignition switch was turned to ON.

      OK
      Engine starts normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (ECM WAS DEFECTIVE)

    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

  10. INSPECT ECM (IMO TERMINAL VOLTAGE)


    1. Disconnect the G50 ECM connector.

    2. Turn the ignition switch to ON.

    3. B003LIMC04
      *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 Ignition switch turned to ON 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 7 Click here

    A

  11. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM AND BODY GROUND)


    1. Disconnect the G127 transponder key ECU assembly connector.

    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
      G127-12 (EFII) - G50-17 (IMO) Always Below 1 Ω
      G127-12 (EFII) - Body ground Always 10 kΩ or higher
      G50-17 (IMO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. REPLACE TRANSPONDER KEY ECU ASSEMBLY


    1. Replace the transponder key ECU assembly with a new one.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  13. REGISTER KEY


    1. Register the key.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  14. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  15. CHECK WHETHER ENGINE STARTS


    1. Using a registered key, turn the ignition switch to ON.

    2. Check that the engine starts 5 seconds after the ignition switch was turned to ON.

      OK
      Engine starts normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE ECM Click here