ENGINE 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 Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B2784

The transponder key amplifier coil built into the engine switch is open or shorted (determined by communication with certification ECU (smart key ECU assembly)) (1 trip detection logic*1):


  • 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

  • Harness or connector

  • Certification ECU (smart key ECU assembly)

 With the shift lever in P*2 or N*3, the electrical key transmitter sub-assembly is held against the engine switch and 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 against engine switch and pressing and holding engine switch with shift lever in P*1 or N*2 -

Related Data List and Active Test
DTC Code Data List and Active Test
B2784 -

WIRING DIAGRAM

A01VGRGE02
*a CODE
*b Engine Switch
*c Certification ECU (Smart Key ECU Assembly)

CAUTION / NOTICE / HINT

Note


  • Before replacing the certification ECU (smart key ECU assembly), refer to the entry and start system (for Entry Function) Click here.

  • 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 F63 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the F59 engine switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F63-1 (VC5) - F59-10 (VC5) Always Below 1 Ω
      F63-7 (CODE) - F59-8 (CODE) Always Below 1 Ω
      F63-9 (TXCT) - F59-7 (TXCT) Always Below 1 Ω
      F63-24 (AGND) - F59-6 (AGND) Always Below 1 Ω
      F63-1 (VC5) - Body ground Always 10 kΩ or higher
      F63-7 (CODE) - Body ground Always 10 kΩ or higher
      F63-9 (TXCT) - Body ground Always 10 kΩ or higher
      F63-24 (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 normally functioning one.

      Tech Tips



    NEXT

  3. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  4. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B2784 is not output.

    OK

    END (ENGINE SWITCH WAS DEFECTIVE)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)