IMMOBILISER 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

When either of the following conditions is met (1-trip detection logic*1):


  • The transponder key amplifier coil built into the engine switch is open (determined by communication with certification ECU (smart key ECU assembly)).

  • The transponder key amplifier coil built into the engine switch is shorted (determined by communication with certification ECU (smart key ECU assembly)).

  • Engine switch

  • Certification ECU (smart key ECU assembly)

DTC output confirmation operation:


  • With the shift lever in P 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.

DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition Always ○ ○
Malfunction Status The transponder key amplifier coil built into the engine switch is open (determined by communication with certification ECU (smart key ECU assembly)). ○ -
The transponder key amplifier coil built into the engine switch is shorted (determined by communication with certification ECU (smart key ECU assembly)). - ○
Detection Time - -
Number of Trips 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

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 P -
Related Data List and Active Test
DTC No. Data List and Active Test
B2784 -

WIRING DIAGRAM

B002CARE18
*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.

  • 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 > Immobiliser > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs.


      Body Electrical > Immobiliser > Trouble Codes

      Tech Tips

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

      OK
      DTC B2784 is not output
      Result
      Result Proceed to
      B2784 is not output A
      B2784 is output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

  3. CHECK ENGINE SWITCH (OUTPUT)


    1. Using an oscilloscope, check the waveform.

      B002EE0C11
      *a

      Component with harness connected

      (Engine Switch)

      		 *b Waveform 1
      *c Waveform 2 *d Waveform 2 (detail)
      Measurement Condition
      Tester Connection Condition Tool Setting Specified Condition
      K35-8 (CODE) - K35-6 (AGND) Engine switch off, engine switch pressed with key held near engine switch*1 2 V/DIV., 20 ms./DIV.

      Pulse generation

      (Waveform 1)
      2 V/DIV., 100 μs./DIV.

      Pulse generation

      (Waveform 2 (detail))

      Tech Tips

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

      OK
      Waveform is similar to that shown in the illustration
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE PUSH ENGINE SWITCH Click here

    OK

  4. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


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

      Tech Tips

      Refer to Service Bulletin.

      Note

      Key ID code registration is necessary when replacing the certification ECU (smart key ECU assembly).

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  5. CLEAR DTC


    1. Clear the DTCs.


      Body Electrical > Immobiliser > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK FOR DTC


    1. Check for DTCs.


      Body Electrical > Immobiliser > Trouble Codes

      Tech Tips

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

      OK
      DTC B2784 is not output
      Result
      Result Proceed to
      B2784 is not output A
      B2784 is output B

    A

    END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

    B

    REPLACE PUSH ENGINE SWITCH Click here