A system includes a control module, a valve control module, and a diagnostic module. The control module controls a valve of a variable intake manifold when the system operates in a first mode. The control module commands the valve to a first position when a desired airflow through the variable intake manifold is greater than a threshold and commands the valve to a second position when the desired airflow is less than the threshold. The valve control module controls the valve when the system operates in a second mode. The valve control module commands the valve to move from the second position to the first position when the desired airflow is less than the threshold. The diagnostic module determines an operating state of the valve based on whether the valve is detected at the first position a predetermined period after the valve control module commands the valve.