ENGINE IMMOBILISER SYSTEM, Diagnostic DTC:B2796, B2798

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

DESCRIPTION

These DTCs are stored if a key that does not have a transponder chip is inserted into the ignition key cylinder or if communication between the key and transponder key ECU is impossible.

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2796 The key code cannot be transmitted (1 trip detection logic*).

  • Key

  • Transponder key ECU assembly

  • Transponder key amplifier

  • Harness or connector

 Insert the key into the ignition key cylinder.
B2798 Key code identification cannot be completed within the specified time (1 trip detection logic*).

  • Key

  • Transponder key ECU assembly

  • Transponder key amplifier

  • Harness or connector

 Insert the key into the ignition key cylinder.

WIRING DIAGRAM

A01CIOVE31

INSPECTION PROCEDURE

Note


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

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

PROCEDURE


  1. 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

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


    1. Disconnect the T18 transponder key ECU connector.

    2. Disconnect the T17 transponder key amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T18-4 (TXCT) - T17-5 (TXCT) Always Below 1 Ω
      T18-5 (AGND) - T17-7 (AGND) Always Below 1 Ω
      T18-14 (VC5) - T17-1 (VC5) Always Below 1 Ω
      T18-15 (CODE) - T17-4 (CODE) Always Below 1 Ω
      T18-4 (TXCT) - Body ground Always 10 kΩ or higher
      T18-5 (AGND) - Body ground Always 10 kΩ or higher
      T18-14 (VC5) - Body ground Always 10 kΩ or higher
      T18-15 (CODE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK TRANSPONDER KEY ECU ASSEMBLY (VC5, AGND)


    1. A01CHHJE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Transponder Key Amplifier)

      Disconnect the T17 transponder key amplifier connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      T17-1 (VC5) - Body ground No key in ignition key cylinder → Key inserted in ignition key cylinder 0 V → 5 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T17-7 (AGND) - Body ground Always Below 1 Ω

    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

    OK

  4. REPLACE TRANSPONDER KEY AMPLIFIER


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

    2. Clear the DTCs Click here.


    NEXT

  5. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC is not output.

    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

    OK

    END (TRANSPONDER KEY AMPLIFIER WAS DEFECTIVE)