ENGINE IMMOBILISER SYSTEM, Diagnostic DTC:B2799

DTC Code DTC Name
B2799 Engine Immobiliser System Malfunction

DESCRIPTION

When there are communication malfunctions between the power management control ECU and ID code box (immobiliser code ECU), or when the communication ID codes do not match, the power management control ECU stores this DTC.

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2799

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


  • A malfunction in the communication or communication lines between the power management control ECU and ID code box (immobiliser code ECU).

  • A matching communication code cannot be verified during communication between the power management control ECU and ID code box (immobiliser code ECU).

  • ID code box (immobiliser code ECU)

  • Power management control ECU

  • Wire harness or connector

Either condition is met:


  • Within 10 seconds of a hybrid control system start operation being performed (with park (P) selected and the brake pedal depressed, press the power switch while carrying the key). If there is a malfunction, the hybrid control system stops (communication begins within 3 seconds of the hybrid control system start operation being performed, and DTCs are stored after 6 seconds).

  • 10 seconds after the power switch is turned on (IG) after reconnecting the cable to the negative (-) terminal of the auxiliary battery (communication begins within 3 seconds of the power 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
Hybrid control system cannot be started -
Related Data List and Active Test
DTC Code Data List and Active Test
B2799 -

WIRING DIAGRAM

B001M4DE20
*a Power Management Control ECU
*b ID Code Box (Immobiliser Code ECU)

CAUTION / NOTICE / HINT

Note


  • If the ID code box (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID.

  • The fixed 12 V power source voltage in the power management control ECU is output through a resistance from terminal IMI. The ID code box (immobiliser code ECU) grounds or does not ground this power source voltage accordingly.

  • The fixed 12 V power source voltage in the ID code box (immobiliser code ECU) is output through a resistance from terminal EFII. The power management control ECU grounds or does not ground this power source voltage accordingly.

  • After performing repair, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

Tech Tips

When DTC B2799 and a DTC for the certification ECU (smart key ECU assembly) are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

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

      OK
      DTC B2799 is not output.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. CHECK POWER MANAGEMENT CONTROL ECU (IMO)


    1. Using an oscilloscope, check the waveform.

      B001MVPE03
      Text in Illustration
      *1 Waveform 1 - -
      *a

      Component with harness connected

      (Power Management Control ECU)

      		 *b Normal Waveform
      Measurement Condition
      Item Content
      Tester Connection H4-20 (IMO) - Body ground
      Tool Setting 2 V/DIV., 200 ms./DIV.
      Condition Within 3 seconds of hybrid control system start or within 3 seconds of power switch turned on (IG) after auxiliary battery cable disconnected and reconnected

      Tech Tips

      The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.

      OK
      Waveform is output normally (refer to illustration).
      Result
      Result Proceed to
      Normal waveform A
      Waveform 1 has abnormal wavelength or shape B
      Terminal IMO stuck high (12 V)
      Terminal IMO stuck low (2.4 V or less) C

    B

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    C

    CHECK ID CODE BOX (IMMOBILISER CODE ECU) (IMO) Click here

    A

  4. CHECK POWER MANAGEMENT CONTROL ECU (IMI)


    1. Using an oscilloscope, check the waveform.

      B001MS5E01
      Text in Illustration
      *1 Waveform 2 - -
      *a

      Component with harness connected

      (Power Management Control ECU)

      		 *b Normal Waveform
      Measurement Condition
      Item Content
      Tester Connection H4-21 (IMI) - Body ground
      Tool Setting 2 V/DIV., 200 ms./DIV.
      Condition Power switch on (IG)

      Tech Tips

      The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.

      OK
      Waveform is output normally (refer to illustration).
      Result
      Result Proceed to
      Normal waveform A
      Waveform 2 not output, or has abnormal wavelength or shape B

    B

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU) Click here

    A

  5. REGISTER RECOGNITION CODES


    1. Register the recognition codes in the ECUs.


    NEXT

  6. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

    2. Check that the hybrid control system can be started with a registered key.

      OK
      Hybrid control system can be started with a registered key.

    OK

    END (ECU COMMUNICATION ID WAS NOT REGISTERED CORRECTLY)

    NG

  7. REPLACE POWER MANAGEMENT CONTROL ECU


    1. Temporarily replace the power management control ECU with a new or known good one Click here.


    NEXT

  8. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  9. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

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

      OK
      DTC is not output.

    OK

    END (POWER MANAGEMENT CONTROL ECU WAS DEFECTIVE)

    NG

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

  10. CHECK ID CODE BOX (IMMOBILISER CODE ECU) (IMO)


    1. Disconnect the H4 power management control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      H4-20 (IMO) - Body ground Power switch on (IG) 11 to 14 V
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    A

  11. CHECK HARNESS AND CONNECTOR (ID CODE BOX - POWER MANAGEMENT CONTROL ECU)


    1. Disconnect the H22 ID code box (immobiliser code ECU) connector.

    2. Disconnect the H4 power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H22-5 (EFII) - H4-20 (IMO) Always Below 1 Ω
      H4-20 (IMO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU) with a new one.


    NEXT

  13. CLEAR DTC


    1. Clear the DTCs Click here.

    2. Register the recognition codes in the ECUs.

    3. Register the ECU communication ID.


    NEXT

  14. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

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

      OK
      DTC is not output.

    OK

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

    NG

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here