×

Monitoring the status of a vehicle

  • US 8,660,739 B2
  • Filed: 04/10/2012
  • Issued: 02/25/2014
  • Est. Priority Date: 01/09/2009
  • Status: Active Grant
First Claim
Patent Images

1. 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.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×