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

  • Wire harness or connector

  • Certification ECU (smart key ECU assembly)

DTC output confirmation operation:

  • With the shift lever in P*2 or N*3 and the key held near the engine switch, an engine start operation is performed by pressing and holding the engine switch when the key battery is depleted.

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

  • *2: for CVT

  • *3: 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 key battery is depleted by holding key near engine switch and pressing and holding engine switch with shift lever in P*1 or N*2

-

  • *1: for CVT

  • *2: for Multi-Mode Manual Transaxle

Table 2. Related Data List and Active Test

DTC No.

Data List and Active Test

B2784

-

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. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ENGINE SWITCH)

    1. Disconnect the E35 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the E36 engine switch connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      E35-7 (CODE) - E36-8 (CODE)

      Always

      Below 1 Ω

      E35-9 (TXCT) - E36-7 (TXCT)

      Always

      Below 1 Ω

      E35-1 (VC5) - E36-10 (VC5)

      Always

      Below 1 Ω

      E35-24 (AGND) - E36-6 (AGND)

      Always

      Below 1 Ω

      E36-8 (CODE) - Body ground

      Always

      10 kΩ or higher

      E35-7 (CODE) - Body ground

      Always

      10 kΩ or higher

      E36-7 (TXCT) - Body ground

      Always

      10 kΩ or higher

      E35-9 (TXCT) - Body ground

      Always

      10 kΩ or higher

      E36-10 (VC5) - Body ground

      Always

      10 kΩ or higher

      E35-1 (VC5) - Body ground

      Always

      10 kΩ or higher

      E36-6 (AGND) - Body ground

      Always

      10 kΩ or higher

      E35-24 (AGND) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. REPLACE ENGINE SWITCH

    1. Temporarily replace the engine switch with a new or known good one.

      except Sedan, for 1ND-TV:Click here

      for Sedan, 1ND-TV:Click hereClick here

      except Sedan, for 1NR-FE:Click here

      for Sedan, 1NR-FE:Click hereClick here

      except Sedan, for 1ZR-FAE:Click here

      for Sedan, 1ZR-FAE:Click hereClick here

      for 1ZR-FE:Click hereClick here

      for 2ZR-FE:Click hereClick here

      for 1WW:Click here

      for 8NR-FTS:Click here

    Result

    Proceed to

    NEXT
    NEXT

  3. CLEAR DTC

    1. Clear the DTCs.

      Body Electrical > Entry&Start > Clear DTCs

    Result

    Proceed to

    NEXT
    NEXT

  4. CHECK FOR DTC

    1. Check for DTCs.

      Body Electrical > Entry&Start > Trouble Codes

      Tip:

      Before checking for DTCs, perform "DTC Output Confirmation Operation" procedure.

      OK

      DTC B2784 is not output.

    Result

    Proceed to

    OK

    NG
    OK

    END (ENGINE SWITCH WAS DEFECTIVE)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)