Dtc B2784 Antenna Coil Open / Short

Vehicle Interior. Corolla. Zre142 Aze141
Theft Deterrent Keyless Entry. Corolla. Zre142 Aze141

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING TECHSTREAM

CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)

INSPECT TRANSPONDER KEY ECU ASSEMBLY (TRANSPONDER KEY AMPLIFIER POWER SOURCE)

INSPECT TRANSPONDER KEY ECU ASSEMBLY (TRANSPONDER KEY AMPLIFIER GROUND)

DTC B2784 Antenna Coil Open / Short


DESCRIPTION

The transponder key coil is built into the transponder key amplifier and receives a key code signal from the transponder chip in the key. This signal is amplified by the amplifier, then it is output to the transponder key ECU assembly.

DTC No.
DTC Detection Condition
Trouble Area
B2784
Antenna coil is open/shorted
  1. Wire harness or connector
  2. Transponder key amplifier
  3. Transponder key ECU assembly

WIRING DIAGRAM


Corolla. Zre142 Aze141.Theft Deterrent Keyless Entry.Smart Key System (For Entry Function). Dtc B2784 Antenna Coil Open / Short


INSPECTION PROCEDURE

NOTICE:
If the transponder key ECU assembly is replaced, register the key and ECU communication ID (COROLLA_ZRE142 RM00000120Y02CX.html).
1.READ VALUE USING TECHSTREAM

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Enter the following menus: Body Electrical / Immobiliser / Data List.

  1. Read the Data List according to the display on the Techstream.

    Immobiliser (Transponder Key ECU Assembly)
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Antenna Coil Status
    		Transponder key amplifier coil condition/Normal or Fail
    		Normal: Antenna coil is normal
    Fail: Antenna coil is malfunctioning
    		-
    OK:
    On the Techstream screen, the item displays Normal according to the chart above.


NG
Go to step 2
OK

REPLACE TRANSPONDER KEY ECU ASSEMBLY (COROLLA_ZRE142 RM000003G05004X.html)

2.CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)

  1. Disconnect the transponder key ECU assembly connector.



    Corolla. Zre142 Aze141.Theft Deterrent Keyless Entry.Smart Key System (For Entry Function). Dtc B2784 Antenna Coil Open / Short

  1. Disconnect the transponder key amplifier connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E21-4 (TXCT) - E29-5 (TXCT)
    		Always
    		Below 1 Ω
    E21-5 (AGND) - E29-7 (AGND)
    		Always
    		Below 1 Ω
    E21-14 (VC5) - E29-1 (VC5)
    		Always
    		Below 1 Ω
    E21-15 (CODE) - E29-4 (CODE)
    		Always
    		Below 1 Ω
    E21-4 (TXCT) - Body ground
    		Always
    		10 kΩ or higher
    E21-5 (AGND) - Body ground
    		Always
    		10 kΩ or higher
    E21-14 (VC5) - Body ground
    		Always
    		10 kΩ or higher
    E21-15 (CODE) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT TRANSPONDER KEY ECU ASSEMBLY (TRANSPONDER KEY AMPLIFIER POWER SOURCE)

  1. Reconnect the transponder key ECU assembly connector.



    Corolla. Zre142 Aze141.Theft Deterrent Keyless Entry.Smart Key System (For Entry Function). Dtc B2784 Antenna Coil Open / Short

  1. Reconnect the transponder key amplifier connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    E21-14 (VC5) - Body ground
    		No key is in ignition key cylinder
    		Below 1 V
    E21-14 (VC5) - Body ground
    		Key is in ignition key cylinder
    		4.6 to 5.4 V


NG
REPLACE TRANSPONDER KEY ECU ASSEMBLY (COROLLA_ZRE142 RM000003G05004X.html)
OK


4.INSPECT TRANSPONDER KEY ECU ASSEMBLY (TRANSPONDER KEY AMPLIFIER GROUND)


    Corolla. Zre142 Aze141.Theft Deterrent Keyless Entry.Smart Key System (For Entry Function). Dtc B2784 Antenna Coil Open / Short

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E21-5 (AGND) - Body ground
    		Always
    		Below 1 Ω


NG
REPLACE TRANSPONDER KEY ECU ASSEMBLY (COROLLA_ZRE142 RM000003G05004X.html)
OK

REPLACE TRANSPONDER KEY AMPLIFIER (COROLLA_ZRE142 RM000003G0L004X.html)