SMART ENTRY AND START SYSTEM(for Start Function), 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 history 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*)

  • Engine switch

  • Certification ECU (smart key ECU assembly)

  • Wire harness or connector

DTC output confirmation operation:


  • With the shift lever in P and the electrical key transmitter sub-assembly 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 electrical key transmitter sub-assembly 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

B006WTHE01
*a CODE
*b Engine Switch
*c 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.

  • The smart entry and start system (for Start Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart entry and start system (for Start Function) after confirming that the communication systems are functioning properly.

    Click here

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

  • After performing repairs, 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.

      B007172C39
      *a

      Component with harness connected

      (Engine Switch)

      		 *b Waveform
      *c Waveform (detail) - -
      OK
      Tester Connection Condition Tool Setting Specified Condition
      K63-8 (CODE) - K63-6 (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.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    NG

    REPLACE ENGINE SWITCH for A25A-FKS: Click here
    REPLACE ENGINE SWITCH for 2GR-FKS: Click here
    REPLACE ENGINE SWITCH for 2AR-FE: Click here