ENGINE IMMOBILISER SYSTEM(w/o Entry and Start System), Diagnostic DTC:B2796, B2798

DTC Code DTC Name
B2796 No Communication in Immobiliser System
B2798 Communication Malfunction No. 2

DESCRIPTION


DTC Code DTC Detection Condition Trouble Area
B2796 The key code cannot be transmitted.

  • Key

  • Harness or connector

  • Transponder key ECU

  • Transponder key amplifier
B2798 Key code identification cannot be completed within the specified time. Key

WIRING DIAGRAM

A004N7QE41
*a CODE
*b Antenna Coil
*c Transponder Key Amplifier
*d Transponder Key ECU

CAUTION / NOTICE / HINT

Tech Tips

When the transponder key ECU is replaced, reregister the ECU - ECM communication ID.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B2796 or B2798 is not output.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. READ VALUE USING INTELLIGENT TESTER (ENGINE IMMOBILISER SYSTEM)


    1. Use the Data List to check if the engine immobiliser system is functioning properly.

      OK
      Unset (the key is inserted in the ignition key cylinder) appears on the screen.
      Immobiliser
      Tester Display Measurement Item / Display Normal Condition Diagnostic Note
      Immobiliser Immobiliser system status / Set or Unset

      Set: No key in ignition key cylinder

      Unset: Key inserted in ignition key cylinder

      		 -

    OK

    REPLACE TRANSPONDER KEY ECU

    NG

  4. CHECK WHETHER ENGINE STARTS WITH OTHER KEYS


    1. Check if the engine starts with an already registered vehicle key.

      OK
      Engine starts.

    OK

    REREGISTER KEY CODE OR REPLACE KEY THAT CANNOT START ENGINE

    NG

  5. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)

    A004OIRE02
    Text in Illustration
    *1

    Front view of wire harness connector

    (to Transponder Key ECU)
    *2

    Front view of wire harness connector

    (to Transponder Key Amplifier)

    1. Disconnect the D102 ECU connector.

    2. Disconnect the D103 amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D102-14 (VC5) - D103-1 (VC5) Always Below 1 Ω
      D102-15 (CODE) - D103-4 (CODE)
      D102-4 (TXCT) - D103-5 (TXCT)
      D102-5 (AGND) - D103-7 (AGND)
      D102-14 (VC5) or D103-1 (VC5) - Body ground Always 10 kΩ or higher
      D102-15 (CODE) or D103-4 (CODE) - Body ground
      D102-4 (TXCT) or D103-5 (TXCT) - Body ground
      D102-5 (AGND) or D103-7 (AGND) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. REPLACE TRANSPONDER KEY AMPLIFIER


    1. Temporarily replace the transponder key amplifier with a new or normally functioning one Click here.


    NEXT

  7. CHECK WHETHER ENGINE STARTS


    1. Check that the engine starts normally.

      OK
      Engine starts normally.

    OK

    END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)

    NG

    REPLACE TRANSPONDER KEY ECU