A modified dual-duplex fail-operational control system. A primary controller includes a first processing unit and a second processing unit for executing a function. A first comparative module comparing the function results from the first and second processing unit to determine an error the first controller. A second controller includes a first processing unit and second processing unit. The first processing unit executes the function. The second processing unit operating in a non-redundant state and not executing the function while in the non-redundant state. A second comparative module determines whether an error is present in the second controller. A matching function result identified by the first comparative module of the first controller is input to second comparative module of the second controller to determine whether an error is present in the second controller utilizing only the matching function result identified by the first comparative module and the function result determined by the first processing unit of the second controller.