A blocked imager detection system includes a rearview assembly having an actuator device. The actuator device is adjustable to tilt an electro-optic element, thereby moving the electro-optic element to an off-axis position which changes an activation state of a display module. The actuator device is also adjustable to tilt the electro-optic element in another direction, thereby moving the electro-optic element to an on-axis position which changes the activation state of the display module. An imager is configured to capture image data of a scene external to the controlled vehicle and to generate image data for display on the display module. When a controller determines that the operational capability of the imager to capture image data is at least partially diminished, the controller can generate a control signal indicating that imager performance has been compromised and deactivate the display module.