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

DTC Code DTC Name
B2784 Antenna Coil Open / Short

DESCRIPTION

When an open or short circuit is detected in the transponder key amplifier coil built into the engine switch, the certification ECU (smart key ECU assembly) stores this DTC. This DTC is also stored as a past DTC.

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2784

The transponder key amplifier coil built into the engine switch is open (see below) or shorted (determined by communication with certification ECU (smart key ECU assembly)) (1 trip detection logic*).


  • Terminal AGND, VC5, TXCT or CODE is open (includes disconnection of the engine switch).

  • The transponder key amplifier coil built into the engine switch is open.

  • Engine switch

  • Wire harness or connector

  • Certification ECU (smart key ECU assembly)

 With the shift lever in P, the key held near the engine switch and an engine start operation is performed by pressing and holding the engine switch when the key battery is depleted.

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
Engine cannot be started when key battery is depleted by holding key near engine switch and pressing and holding engine switch with shift lever in P -
Related Data List and Active Test
DTC Code Data List and Active Test
B2784 -

WIRING DIAGRAM

B000LA5E04

INSPECTION PROCEDURE

Note


  • Before replacing the certification ECU (smart key ECU assembly), refer to Service Bulletin.

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

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK DTC OUTPUT


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs Click here.

      OK
      DTC B2784 is not output.

    NG

    CHECK ENGINE SWITCH (OUTPUT) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. CHECK ENGINE SWITCH (OUTPUT)


    1. Using an oscilloscope, check the waveform.

      B000NF7E02
      Text in Illustration
      *a

      Component with harness connected

      (Engine Switch)

      		 *b Waveform
      *c Waveform (detail) - -
      Measurement Condition
      Tester Connection Condition Tool Setting Specified Condition
      I58-8 (CODE) - I58-6 (AGND) Engine switch off, engine switch pressed with key held near engine switch* 1 V/DIV., 20 ms./DIV.

      Pulse generation

      (See waveform)
      2 V/DIV., 100 μs./DIV.

      Pulse generation

      (See waveform (detail))

      • *: Remove the key battery before performing this inspection.

      OK
      The waveform is similar to that shown in the illustration
      Result
      Result Proceed to
      OK A
      NG (for 2GR-FE) B
      NG (for 2AR-FE) C
      NG (for 6AR-FSE) D

    B

    REPLACE ENGINE SWITCH Click here

    C

    REPLACE ENGINE SWITCH Click here

    D

    REPLACE ENGINE SWITCH Click here

    A

  4. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. Replace the certification ECU (smart key ECU assembly) with a new one.

      Tech Tips

      Refer to Service Bulletin.


    NEXT

  5. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.


    NEXT

  6. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  7. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs Click here.

      OK
      DTC B2784 is not output.
      Result
      Result Proceed to
      OK A
      NG (for 2GR-FE) B
      NG (for 2AR-FE) C
      NG (for 6AR-FSE) D

    B

    REPLACE ENGINE SWITCH Click here

    C

    REPLACE ENGINE SWITCH Click here

    D

    REPLACE ENGINE SWITCH Click here

    A

    END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)