ENGINE IMMOBILISER SYSTEM, Diagnostic DTC:B2799-790

DTC Code DTC Name
B2799-790 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
B2799-790

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

  • Harness or connector

Either condition is met:


  • Within 10 seconds of an hybrid system start operation being performed (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 system stops (communication begins within 3 seconds of the hybrid 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 (-) 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 system cannot be started -
Related Data List and Active Test
DTC Code Data List and Active Test
B2799-790 -

WIRING DIAGRAM

A000SI0E02
*a Power Management Control ECU
*b ID Code Box (Immobiliser Code ECU)

CAUTION / NOTICE / HINT

Note


  • When replacing the ID code box (immobiliser code ECU), refer to the Service Bulletin.

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

Tech Tips

When DTC B2799-790 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. CHECK HARNESS AND CONNECTOR (ID CODE BOX [IMMOBILISER CODE ECU] - POWER MANAGEMENT CONTROL ECU)


    1. Disconnect the N73 ID code box (immobiliser code ECU) connector.

    2. Disconnect the N92 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
      N73-3 (EFII) - N92-28 (IMO) Always Below 1 Ω
      N92-28 (IMO) - Body ground Always 10 kΩ or higher
      N73-4 (EFIO) - N92-29 (IMI) Always Below 1 Ω
      N92-29 (IMI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to the Service Bulletin.


    NEXT

  3. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  4. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

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

      OK
      DTC B2799-790 is not output.

    OK

    END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED)

    NG

  5. REPLACE POWER MANAGEMENT CONTROL ECU


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


    NEXT

  6. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  7. CHECK FOR DTC


    1. Check for DTCs Click here.

      Tech Tips

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

      OK
      DTC B2799-790 is not output.

    OK

    END (POWER MANAGEMENT CONTROL ECU WAS DEFECTIVE)

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)