B2780

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2780: Push Switch / Key Unlock Warning Switch Malfunction

DTC B2780 - Push Switch / Key Unlock Warning Switch Malfunction

DESCRIPTION

This DTC will be output when the key is inserted into the ignition key cylinder, but the transponder key ECU does not detect the ON condition of the unlock warning switch. Normally, inserting the key into the ignition key cylinder turns ON the unlock warning switch, which is then detected by the ECU.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE OF INTELLIGENT TESTER (UNLOCK WARNING SWITCH ASSEMBLY)
(a) Check the DATA LIST for proper functioning of the unlock warning switch.

Transponder key ECU assembly





OK:
ON (key is in ignition key cylinder) appears on the screen.
OK -- REPLACE TRANSPONDER KEY ECU ASSEMBLY
NG -- Continue to next step.
2. INSPECT UNLOCK WARNING SWITCH ASSEMBLY





(a) Remove the unlock warning switch.
(b) Measure the resistance of the switch.
Standard resistance:






NG -- REPLACE UNLOCK WARNING SWITCH ASSEMBLY
OK -- Continue to next step.
3. CHECK WIRE HARNESS (UNLOCK WARNING SWITCH - TRANSPONDER KEY ECU AND BODY GROUND)





(a) Disconnect the U1 switch connector.
(b) Disconnect the T8 ECU connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE TRANSPONDER KEY ECU ASSEMBLY