IMMOBILISER SYSTEM(w/ 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 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*1)

  • 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 N*2 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.

  • *1: Only output while a malfunction is present.

  • *2: for Multi-Mode Manual Transaxle

Table 1. 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 N*

-

  • *: for Multi-Mode Manual Transaxle

Table 2. Related Data List and Active Test

DTC No.

Data List and Active Test

B2784

-

WIRING DIAGRAM

E271702E11

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 hereClick here

    NG

  3. CHECK ENGINE SWITCH (OUTPUT)

    1. Using an oscilloscope, check the waveform.

      E293555C05

      *a

      Component with harness connected

      (Engine Switch)

      *b

      Waveform 1

      *c

      Waveform 2

      *d

      Waveform 2 (detail)
      Table 3. Waveform 1

      Tester Connection

      Condition

      Tool Setting

      Specified Condition

      E51-8 (CODE) - Body ground

      Engine switch off, engine switch pressed with key held near engine switch*

      1 V/DIV., 20 ms./DIV.

      Pulse generation

      (See waveform1)

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

      Table 4. Waveform 2 (detail)

      Tester Connection

      Condition

      Tool Setting

      Specified Condition

      E51-8 (CODE) - Body ground

      Engine switch off, engine switch pressed with key held near engine switch*

      1 V/DIV., 20 ms./DIV.

      Pulse generation

      (See waveform 2 (detail))

      • *: Remove the key 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

    for 1KR-FE:Click here

    for 1PP:Click here

    OK

  4. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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

      Tip:

      Refer to Service Bulletin.

    Result

    Proceed to

    NEXT
    NEXT

  5. REGISTER ECU COMMUNICATION ID

    1. Register the ECU communication ID.

      Tip:

      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

    for 1KR-FE:Click here

    for 1PP:Click here