Dtc B2780 Push Switch / Key Unlock Warning Switch Malfunction


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (UNLOCK WARNING SWITCH)

INSPECT UNLOCK WARNING SWITCH ASSEMBLY

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

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
  2. Wire harness
  3. Transponder key ECU

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B2780 Push Switch / Key Unlock Warning Switch Malfunction


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (UNLOCK WARNING SWITCH)

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

    Transponder key ECU:
    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
NG


2.INSPECT UNLOCK WARNING SWITCH ASSEMBLY
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B2780 Push Switch / Key Unlock Warning Switch Malfunction

  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)
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B2780 Push Switch / Key Unlock Warning Switch Malfunction

  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


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE TRANSPONDER KEY ECU