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 assembly

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

WIRING DIAGRAM

A00O9UNE07

INSPECTION PROCEDURE

Note

When replacing the transponder key ECU assembly, refer to the Service Bulletin.

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.

    NG

    READ VALUE USING INTELLIGENT TESTER (ENGINE IMMOBILISER SYSTEM) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

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


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

      Immobiliser
      Tester Display Measurement Item/Range 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
      Set (the key is not inserted in the ignition key cylinder) and Unset (the key is inserted in the ignition key cylinder) appear on the screen according to the key insertion condition.

    NG

    CHECK WHETHER ENGINE STARTS WITH OTHER KEYS Click here

    OK

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

  4. CHECK WHETHER ENGINE STARTS WITH OTHER KEYS


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

      OK
      Engine starts.

    NG

    CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER) Click here

    OK

    REREGISTER KEY CODE OR REPLACE KEY THAT CANNOT START ENGINE

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


    1. Disconnect the G138*1 or G74*2 ECU connector.


      • *1: for 5L-E

      • *2: except 5L-E

    2. Disconnect the G75 amplifier connector.

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

      Standard Resistance
      for 5L-E
      Tester Connection Condition Specified Condition
      G138-14 (VC5) - G75-1 (VC5) Always Below 1 Ω
      G138-15 (CODE) - G75-4 (CODE)
      G138-4 (TXCT) - G75-5 (TXCT)
      G138-5 (AGND) - G75-7 (AGND)
      G138-14 (VC5) or G75-1 (VC5) - Body ground Always 10 kΩ or higher
      G138-15 (CODE) or G75-4 (CODE) - Body ground
      G138-4 (TXCT) or G75-5 (TXCT) - Body ground
      G138-5 (AGND) or G75-7 (AGND) - Body ground
      except 5L-E
      Tester Connection Condition Specified Condition
      G74-14 (VC5) - G75-1 (VC5) Always Below 1 Ω
      G74-15 (CODE) - G75-4 (CODE)
      G74-4 (TXCT) - G75-5 (TXCT)
      G74-5 (AGND) - G75-7 (AGND)
      G74-14 (VC5) or G75-1 (VC5) - Body ground Always 10 kΩ or higher
      G74-15 (CODE) or G75-4 (CODE) - Body ground
      G74-4 (TXCT) or G75-5 (TXCT) - Body ground
      G74-5 (AGND) or G75-7 (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.

    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

    OK

    END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)