A high frequency injection (HF) technique for rotor position estimation using Sliding Mode Control (SMC) in Permanent Magnet Synchronous Machines (PMSMs) is presented. Since SMC is used, instead of the Field Oriented Control (FOC), the injected HF test signals for tracking the machine's saliency are naturally eliminated. Such angle information suppression is tackled using"the equivalent control" principle. Simulation results confirm not only the proper angle estimation but also the sensorless control at low speed reversal and load impact at zero speed.