A system, apparatus and method are provided for testing a secondary servo control circuit in a redundant control configuration. A first circuit is configured to receive a control signal and to control an attribute of an actuator based on the control signal using a first control input of the actuator. A second circuit is configured to test operation of an actuator circuit using a test signal. The actuator circuit includes at least part of the second circuit and a second control input of the actuator. The test signal is selected to avoid causing independent motion of the actuator. The actuator could be a dual coil servo valve, and the test signal could be a current (such as a DC current, an AC current, or a pulsed current) having a magnitude less than a bias current of the actuator.