Patent ID: 8660739

Claim:
A method for determining the ignition state of a vehicle without monitoring the state of an ignition switch, the method comprising the steps of: (a) measuring a voltage across a primary winding of a vehicle ignition coil during a first sample period by way of a central processing unit (CPU) connected to said primary winding by way of a port, defining a first sample voltage; (b) storing said first sample voltage in memory associated with said CPU; (c) measuring the voltage of the primary winding of the vehicle ignition coil during a second sample period by way of a CPU connected to said primary winding by way of a port, defining a second sample voltage; (d) storing said second sample voltage in memory associated with said CPU; (e) comparing by way of said CPU said first sample voltage and said second sample voltage defining a comparison; and (f) providing an indication by way of said CPU of said ignition state as a function of said comparison.