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 is 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

A01EU39E01

INSPECTION PROCEDURE

Note


  • Before replacing the certification ECU (smart key ECU assembly), refer to the 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. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ENGINE SWITCH)


    1. Disconnect the I78 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the I58 engine switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I78-7 (CODE) - I58-8 (CODE) Always Below 1 Ω
      I78-9 (TXCT) - I58-7 (TXCT) Always Below 1 Ω
      I78-1 (VC5) - I58-10 (VC5) Always Below 1 Ω
      I78-24 (AGND) - I58-6 (AGND) Always Below 1 Ω
      I58-8 (CODE) - Body ground Always 10 kΩ or higher
      I58-7 (TXCT) - Body ground Always 10 kΩ or higher
      I58-10 (VC5) - Body ground Always 10 kΩ or higher
      I58-6 (AGND) - Body ground Always 10 kΩ or higher

    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 Click here for 2GR-FE, Click here for 2AR-FE).


    NEXT

  3. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  4. CHECK DTC OUTPUT


    1. Check for DTCs Click here.

      Tech Tips

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

      OK
      DTC B2784 is not output.

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

    END (ENGINE SWITCH WAS DEFECTIVE)