Patent ID: 7631626

Claim:
A method to protect a starter from overheating during cranking operations preparatory to starting an electronically controlled internal combustion engine having an electronic control unit (ECU), and at least one temperature sensor, an ignition switch, a battery connected to a starter and a relay switch between the battery and the starter, comprising: a) determining whether the starter temperature and duration of time an ignition switch is in the “off” position is greater than a predetermined ignition time; based on a prior crank event; b) approximating the starter temperature with ECU temperature; c) cranking the starter and determining a change in battery voltage between resting and cranking to a change in current; d) multiply the change in current by a predetermined coefficient to convert to a change in temperature and add to the change in temperature to a last starter temperature stored in memory; e) ceasing starter operation and bringing starter temperature to approximate ECU temperature; f) disabling the starter if the starter temperature is above a predetermined temperature until the starter is at or below said predetermined temperature.