IMMOBILISER SYSTEM, Diagnostic DTC:B2799-790

DTC Code DTC Name
B2799-790 Engine Immobiliser System Malfunction

DESCRIPTION

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

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2799-790

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


  • A malfunction in the communication or communication lines between the hybrid vehicle control ECU assembly and ID code box (immobiliser code ECU).

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

  • ID code box (immobiliser code ECU)

  • Hybrid vehicle control ECU assembly

  • Wire harness or connector

Either condition is met:


  • 10 seconds after a hybrid control system start operation (with the shift lever in P and the brake pedal depressed, the power switch is pressed while carrying the key). If there is a malfunction, the hybrid control system does not start (communication begins within 3 seconds of the hybrid control system start operation, and DTCs are stored after 6 seconds).

  • 10 seconds after the power switch is turned on (IG) after reconnecting the cable to the negative (-) auxiliary battery terminal (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
B2799-790 -

WIRING DIAGRAM

A00087DE03
*a Hybrid Vehicle Control ECU assembly
*b ID Code Box (Immobiliser Code ECU)

CAUTION / NOTICE / HINT

Note


  • When replacing the ID code box (immobiliser code ECU) or hybrid vehicle control ECU assembly, refer to the Service Bulletin.

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

Tech Tips

When DTC B2799-790 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. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Start the hybrid control system.

    2. Wait 10 seconds or more.

    3. Check for DTCs Click here.

      Tech Tips

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

      OK
      DTC B2799-790 is not output.
      Result
      Result Proceed to
      OK A
      NG (DTC B2799-790 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 HYBRID VEHICLE CONTROL ECU ASSEMBLY (TERMINAL IMO)


    1. Using an oscilloscope, check the waveform.

      A0008QVE02
      Text in Illustration
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU Assembly)

      		 *b Waveform
      Measurement Condition
      Item Content
      Tester Connection H212-23 (IMO) - Body ground
      Tool Setting 2 V/DIV., 500 ms./DIV.
      Condition Within 3 seconds after hybrid control system starts, or within 3 seconds after power switch first turned to on (IG) after auxiliary battery disconnected and reconnected
      OK
      Waveform is output normally (refer to 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 HYBRID VEHICLE CONTROL ECU ASSEMBLY (IMO TERMINAL VOLTAGE) Click here

    C

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    A

  4. INSPECT HYBRID VEHICLE CONTROL ECU ASSEMBLY (TERMINAL IMI)


    1. Using an oscilloscope, check the waveform.

      A0006KIE02
      Text in Illustration
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU Assembly)

      		 *b Waveform
      Measurement Condition
      Item Content
      Tester Connection H212-22 (IMI) - Body ground
      Tool Setting 2 V/DIV., 500 ms./DIV.
      Condition Within 3 seconds after hybrid control system starts, or within 3 seconds after power switch first turned to on (IG) after auxiliary battery disconnected and reconnected
      OK
      Waveform is output normally (refer to illustration).
      Result
      Result Proceed to
      Normal waveform A
      Not output waveform or abnormal waveform B

    B

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU) Click here

    A

  5. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  6. CHECK WHETHER HYBRID CONTROL SYSTEM STARTS


    1. Check that the hybrid control system starts with an already registered vehicle key.

      OK
      Hybrid control system starts normally.

    OK

    END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

  7. INSPECT HYBRID VEHICLE CONTROL ECU ASSEMBLY (IMO TERMINAL VOLTAGE)


    1. A0006LZE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

      Disconnect the H212 hybrid vehicle control ECU assembly connector.

    2. Turn the power switch on (IG).

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

      Result
      Result Proceed to
      Terminal IMO stuck low (2.4 V or less) A
      Terminal IMO stuck high (12 V) B

    B

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    A

  8. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - ID CODE BOX AND BODY GROUND)


    1. Disconnect the H15 ID code box (immobiliser code ECU) connector.

    2. Disconnect the H212 hybrid vehicle control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H15-3 (EFII) - H212-23 (IMO) Always Below 1 Ω
      H2-23 (IMO) - Body ground Always 10 kΩ or higher
      H15-4 (EFIO) - H212-22 (IMI) Always Below 1 Ω
      H2-22 (IMI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU).

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  10. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  11. CHECK WHETHER HYBRID CONTROL SYSTEM STARTS


    1. Check that the hybrid control system starts with an already registered vehicle key.

      OK
      Hybrid control system starts normally.

    OK

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

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

  12. REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY


    1. Temporarily replace the hybrid vehicle control ECU assembly with a new one Click here.


    NEXT

  13. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  14. CHECK WHETHER HYBRID CONTROL SYSTEM STARTS


    1. Check that the hybrid control system starts with an already registered vehicle key.

      OK
      Hybrid control system starts normally.

    OK

    END (HYBRID VEHICLE CONTROL ECU ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)