Dtc B2784 Antenna Coil Open / Short

Vehicle Interior. Yaris. Ncp93, 131
Theft Deterrent Keyless Entry. Yaris. Ncp93, 131

DESCRIPTION

INSPECTION PROCEDURE

CLEAR DTC

CHECK FOR DTC

CHECK TRANSPONDER KEY AMPLIFIER (OUTPUT)

REPLACE TRANSPONDER KEY ECU ASSEMBLY

REGISTER KEY

REGISTER ECU COMMUNICATION ID

CLEAR DTC

CHECK FOR DTC

DTC B2784 Antenna Coil Open / Short


DESCRIPTION

The antenna coil receives key code signals from the transponder chip in the key grip. The antenna coil is built into the transponder key amplifier, which amplifies the key code signals and outputs the signals to the transponder key ECU assembly.
This DTC is stored when there is an open or short in the antenna coil.

DTC Code
DTC Detection Condition
Trouble Area
DTC Output Confirmation Operation
B2784
The antenna coil built into the transponder key amplifier is open or shorted (determined by communication with transponder key ECU assembly) (1 trip detection logic*).
  1. Terminal VC5, TXCT or CODE is open.
  2. The antenna coil built into the transponder key amplifier is open.
  1. Harness or connector
  2. Transponder key amplifier
  3. Transponder key ECU assembly
Insert the key into the ignition key cylinder.
  1. *: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected
Fail-safe Operation when Malfunction Detected
Engine cannot be started
-

Related Data List and Active Test
DTC Code
Data List and Active Test
B2784
Antenna Coil Status

INSPECTION PROCEDURE

NOTICE:
  1. When replacing the transponder key ECU assembly, refer to the Registration (YARIS_NCP93 RM00000120Y021X.html).
  2. After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.
1.CLEAR DTC

  1. Clear the DTCs (YARIS_NCP93 RM000001TCQ01OX.html).


NEXT


2.CHECK FOR DTC

  1. Check for DTCs (YARIS_NCP93 RM000001TCQ01OX.html).

    HINT:
    Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.
    OK:
    DTC B2784 is not output.


NG
Go to step 3
OK

USE SIMULATION METHOD TO CHECK (YARIS_NCP93 RM00000135202EX.html)

3.CHECK TRANSPONDER KEY AMPLIFIER (OUTPUT)


    Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2784 Antenna Coil Open / Short

  1. Using an oscilloscope, check the waveform.

    1. Waveform (Reference)

      Measurement Condition
      Item
      		Content
      Tester Connection
      		D140-4 (CODE) - D140-7 (AGND)
      Tool Setting
      		1 V/DIV., 100 μs./DIV.
      Condition
      		Key inserted in ignition key cylinder
      OK:
      Waveform is output normally (see illustration).
      Text in Illustration
      *a
      		Component with harness connected
      (Transponder Key Amplifier)
      *b
      		Waveform


NG
REPLACE TRANSPONDER KEY AMPLIFIER (YARIS_NCP93 RM000003RZI00HX.html)
OK


4.REPLACE TRANSPONDER KEY ECU ASSEMBLY

  1. Replace the transponder key ECU assembly (YARIS_NCP93 RM000004E7M008X.html).


NEXT


5.REGISTER KEY

  1. Reregister the key (YARIS_NCP93 RM00000120Y021X.html).


NEXT


6.REGISTER ECU COMMUNICATION ID

  1. Register the ECU communication ID (YARIS_NCP93 RM00000120Y021X.html).


NEXT


7.CLEAR DTC

  1. Clear the DTCs (YARIS_NCP93 RM000001TCQ01OX.html).


NEXT


8.CHECK FOR DTC

  1. Check for DTCs (YARIS_NCP93 RM000001TCQ01OX.html).

    HINT:
    Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.
    OK:
    DTC B2784 is not output.


NG
REPLACE TRANSPONDER KEY AMPLIFIER (YARIS_NCP93 RM000003RZI00HX.html)
OK

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)