IMMOBILISER 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 No. Detection Item DTC Detection Condition Trouble Area Note
B2784 Antenna Coil Open / Short

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 circuit is open (includes disconnection of the engine switch).

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

  • Engine switch

  • Certification ECU (smart key ECU assembly)

  • Wire harness or connector

DTC output confirmation operation:


  • With the shift lever in P and the key held near the engine switch, an engine start operation is performed by pressing and holding the engine switch when the transmitter 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 transmitter battery is depleted by holding transmitter near engine switch and pressing and holding engine switch with shift lever in P -
Related Data List and Active Test
DTC No. Data List and Active Test
B2784 -

WIRING DIAGRAM

B0065EWE29
*1 CODE
*2 Engine Switch
*3 Certification ECU (Smart Key ECU Assembly)

CAUTION / NOTICE / HINT

Note


  • When using the GTS with the engine switch off, connect the GTS to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Entry&Start(CAN). While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.

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

  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.


      Body Electrical > Entry&Start > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Body Electrical > Entry&Start > Trouble Codes
      OK
      DTC B2784 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. CHECK ENGINE SWITCH (OUTPUT)


    1. Using an oscilloscope, check the waveform.

      B0067HEC03
      *a

      Component with harness connected

      (Engine Switch)

      		 *b Waveform
      *c Waveform (detail) - -
      Measurement Condition
      Tester Connection Condition Tool Setting Specified Condition
      O49-8 (CODE) - O49-6 (AGND) Engine switch off, engine switch pressed with electrical key transmitter sub-assembly 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 transmitter battery before performing this inspection.

      OK
      The waveform is similar to that shown in the illustration
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE ENGINE SWITCH Click here

    OK

  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.

      Result
      Proceed to
      NEXT

    NEXT

  5. REGISTER ECU COMMUNICATION ID


    1. Register the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  6. CLEAR DTC


    1. Clear the DTCs.


      Body Electrical > Entry&Start > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTC


    1. Perform "DTC Output Confirmation Operation" procedure.

    2. Check for DTCs.


      Body Electrical > Entry&Start > Trouble Codes
      OK
      DTC B2784 is not output.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE ENGINE SWITCH Click here