Key-in sensor

When the ignition key is inserted into the lock barrel the key-in sensor contacts close and supply a signal to the BCU. The BCU monitors the ignition switch for a change in state and triggers the alarm if it receives an ignition signal before it receives an alarm disarm signal.

Another feed to the ignition switch is provided by the BCU to provide switch illumination.

A key-in warning can be enabled or disabled. When the key-in warning is enabled, an audible warning is generated if the ignition key is in and the driver's door is opened.