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, and output to the transponder key ECU.

DTC No.	DTC Detection Condition	Trouble Area
B2784	Antenna coil open/short	Transponder key amplifier Wire harness Transponder key ECU assembly

WIRING DIAGRAM

INSPECTION PROCEDURE

1. READ VALUE OF INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch on and turn the intelligent tester main switch on.

3. Select Antenna Coil Status in the DATA LIST and read the value displayed on the intelligent tester.

   Transponder key ECU: 

   Item	Measurement Item/Display (Range)	Normal Condition	Diagnostic Note
   Antenna Coil Status	Antenna coil condition /NORMAL or FAIL	NORMAL: Antenna coil is normal. FAIL: Antenna coil is malfunctioning.	-

   OK:

   NORMAL (Antenna coil is normal) appears on the screen.
   

OK	REPLACE TRANSPONDER KEY ECU ASSEMBLY

NG

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

1. Disconnect the T8 ECU and T7 switch connectors.

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

   Resistance:

   Tester Connection	Specified Condition
   T8-9 (VC5) - T7-1 (VC5)	Below 1 Ω
   T8-10 (CODE) - T7-4 (CODE)
   T8-12 (TXCT) - T7-5 (TXCT)
   T8-13 (AGND) - T7-7 (GND)
   T8-9 (VC5) or T7-1(VC5) - Body ground	10 kΩ or higher
   T8-10 (CODE) or T7-4 (CODE) - Body ground
   T8-12 (TXCT) or T7-5 (TXCT) - Body ground
   T8-13 (AGND) or T7-7 (GND) - Body ground

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3. INSPECT TRANSPONDER KEY ECU ASSEMBLY

1. Reconnect the T8 ECU and T7 amplifier connectors.

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

   Voltage:

   Tester Connection	Condition	Specified Condition
   T8-9 (VC5) - Body ground	No key is in ignition key cylinder	Below 1 V
   	Key is in ignition key cylinder	4.6 to 5.4 V

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

   Resistance:

   Tester Connection	Condition	Specified Condition
   T9-13 (AGND) - Body ground	Always	Below 1 Ω

NG	REPLACE TRANSPONDER KEY ECU ASSEMBLY

OK

4. CHECK OPERATION OF TRANSPONDER KEY AMPLIFIER

1. After replacing the transponder key amplifier with a normally functioning transponder key amplifier, check that the hybrid control system starts.

   OK:

   Hybrid control system starts.
   

NG	REPLACE TRANSPONDER KEY ECU ASSEMBLY

OK
END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)