SC 430 V8-4.3L (3UZ-FE) (2003)
Audible Warning Device: Symptom Related Diagnostic Procedures
Door Courtesy Switch Assy (For Front Door) Circuit
CIRCUIT DESCRIPTION
The driver's side courtesy lamp switch signals are transmitted multiply to the theft warning ECU from the door ECU. When the ignition switch is OFF,
the key is in the ignition switch lock cylinder, and the driver's door is opened, the theft warning ECU commands the meter ECU multiply to make the
buzzer sound and the buzzer inside the meter ECU sounds.
NOTE: The key un-lock warning system has a function with a large-scale multiplex communication. First of all, inspect the communication function
according to "How To Proceed With Troubleshooting", and check that no malfunction exists in the communication system. Then proceed with the
troubleshooting.
Wiring Diagram
Step 1