B2780

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 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.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (UNLOCK WARNING SWITCH)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON with the key that cannot start the engine.
(c) On the Techstream, enter the following menus: Body Electrical / Immobiliser / Data List / Key SW. Read the values.

Immobiliser





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:





(c) Reinstall the unlock warning switch.
NG -- REPLACE UNLOCK WARNING SWITCH ASSEMBLY
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - UNLOCK WARNING SWITCH)





(a) Disconnect the T10 ECU connector.
(b) Disconnect the U1 switch connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:





(d) Reconnect the unlock warning switch connector.
(e) Reconnect the ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE TRANSPONDER KEY ECU ASSEMBLY