Patent ID: 7545111

Claim:
A method of testing automotive vehicle electric traction motor shut-off paths, the method comprising the steps of: providing a three-phase electric motor having at least one shut-off path that is an electric traction motor of an automotive vehicle, a source of electric current, a current injection circuit connected to the source of electric current and to the three-phase electric motor, and current measurement circuitry and electrical communication with the three-phase electrical motor; injecting current into the three-phase electric motor; applying at least one of a short or an open to the three-phase electric motor for a predetermined length of time; calculating a rate of decay of the current; comparing the rate of decay wit predetermined decay criteria; and determining that testing of the at least one shut-off path of the three-phase electric motor has passed if the rate of decay meets the predetermined decay criteria and that the at least one shut-off path has failed if the rate of decay does not meet the predetermined decay criteria.