ENGINE IMMOBILISER SYSTEM (w/o Entry and Start System), Diagnostic DTC:B2797

DTC Code DTC Name
B2797 Communication Malfunction No. 1

DESCRIPTION

This DTC is stored when a communication error occurs between the transponder key amplifier and transponder key ECU. Some possible reasons for the communication error are: 1) 2 or more ignition keys are positioned too close together, or 2) noise is occurring in the communication line.

DTC Code DTC Detection Condition Trouble Area
B2797 2 or more ignition keys are positioned too close to each other, or noise occurs in the communication line.

  • Key

  • Harness or connector

  • Transponder key amplifier

  • Transponder key ECU

WIRING DIAGRAM

A01ISH3E15

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. CHECK KEY


    1. Check whether the ignition key being used is near other ignition keys. Also, check whether a key ring is in contact with the key grip.

      Result
      Result Proceed to
      Key is near other keys and/or key ring is in contact with key grip A
      Key is not near other keys and key ring is not in contact with key grip B

    B

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

    A

  2. CHECK FOR DTC


    1. Separate the keys from each other, or remove the key ring.

    2. Clear the DTCs Click here.

    3. Insert a key into the ignition key cylinder, and then remove it. Repeat for all the other keys.

    4. Check that no DTC is output Click here.

      OK
      DTC B2797 is not output.

    NG

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

    OK

    END

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


    1. A01IROTE12
      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)

      Disconnect the H110 ECU connector.

    2. Disconnect the H44 amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H110-15 (CODE) - H44-4 (CODE) Always Below 1 Ω
      H110-15 (CODE) or H44-4 (CODE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK TRANSPONDER KEY ECU (NOISE)


    1. A01IQ3DE11

      Using an oscilloscope or the intelligent tester, check for noise in the waveform between the terminals of the H44 amplifier connector and H110 ECU connector.

      Measurement Condition
      Item Content
      Tester Connection H44-4 (CODE) - H110-15 (CODE)
      Tool Setting 5 V/DIV., 20 msec./DIV.
      Condition Key inserted in ignition key cylinder
      OK
      No noise is present.

    NG

    FIND CAUSE OF NOISE AND REMOVE IT

    OK

  5. REPLACE TRANSPONDER KEY AMPLIFIER


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


    NEXT

  6. CHECK WHETHER ENGINE STARTS


    1. Check that the engine starts normally.

      OK
      Engine starts.

    NG

    REPLACE TRANSPONDER KEY ECU

    OK

    END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)