ENGINE IMMOBILISER SYSTEM (w/ Smart Entry and Start System), Diagnostic DTC:B2784

DTC Code DTC Name
B2784 Antenna Coil Open / Short

DESCRIPTION

This DTC is output when there is an open or short in the key coil (built into the engine switch).

DTC No. DTC Detection Condition Trouble Area
B2784 Antenna coil is open/shorted

  • Wire harness or connector

  • Certification ECU (Smart key ECU assembly)

  • Engine switch

WIRING DIAGRAM

A017CZ4E04

INSPECTION PROCEDURE

Note

If the certification ECU (smart key ECU assembly) is replaced, register the key and ECU communication ID.

PROCEDURE


  1. CHECK DTC OUTPUT


    1. Delete the DTCs Click here.

    2. Recheck for DTCs.

      OK
      B2784 output does not recur.

    NG

    CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ENGINE SWITCH) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ENGINE SWITCH)


    1. A017FIVE01

      Disconnect the certification ECU (smart key ECU assembly) and engine switch connectors.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D36-9 (CODE) - D22-10 (CODE) Always Below 1 Ω
      D36-8 (TXCT) - D22-9 (TXCT) Always Below 1 Ω
      D36-9 (CODE) - Body ground Always 10 kΩ or higher
      D36-8 (TXCT) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. REPLACE ENGINE SWITCH


    1. Replace the engine switch Click here.


    NEXT

  4. CHECK DTC OUTPUT


    1. Delete the DTCs Click here.

    2. Recheck for DTCs.

      OK
      B2784 output does not recur.

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

    END (ENGINE SWITCH IS DEFECTIVE)