DTC    B2780    Push Switch / Key Unlock Warning Switch Malfunction


DESCRIPTION

This DTC will be output if the transponder key ECU does not detect that the unlock warning switch is ON even when the key is inserted into the ignition key cylinder. Under normal conditions, the unlock warning switch is ON when the key is inserted into the ignition key cylinder.

DTC No.
DTC Detection Condition
Trouble Area
B2780
Unlock warning switch ON is not detected when key is inserted into ignition key cylinder
  1. Unlock warning switch assembly
  2. Wire harness
  3. Transponder key ECU assembly

WIRING DIAGRAM


B110397E02


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER (UNLOCK WARNING SWITCH ASSEMBLY)

  1. Check the Data List for proper functioning of the unlock warning switch.

    Transponder key ECU assembly: 
    Item
    		Measurement Item/Display (Range)
    		Normal Condition
    		Diagnostic Note
    Key SW
    		Unlock warning switch signal / ON or OFF
    		OFF: No key is in ignition key cylinder
    ON: Key is in ignition key cylinder
    		-

    OK:
    ON (key is in ignition key cylinder) appears on screen.



OK
REPLACE TRANSPONDER KEY ECU ASSEMBLY
NG


2.INSPECT UNLOCK WARNING SWITCH ASSEMBLY
B110401E01

  1. Remove the switch.

  1. Measure the resistance of the switch.

    Standard resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    1 - 2
    		Pushed
    		Below 1 Ω
    Not pushed
    		10 kΩ or higher



NG
REPLACE UNLOCK WARNING SWITCH ASSEMBLY
OK


3.CHECK WIRE HARNESS (UNLOCK WARNING SWITCH - TRANSPONDER KEY ECU AND BODY GROUND)
B110402E01

  1. Disconnect the U1 switch connector.

  1. Disconnect the T21 ECU connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    T21-3 (KSW) - U1-1
    		Below 1 Ω
    U1-2 - Body ground
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE TRANSPONDER KEY ECU ASSEMBLY