A control system and a method for validating operation of the control system are provided. The control system has a first controller operably communicating with a second controller. The first and second controllers have first and second read-only memories, respectively. The method includes executing a first software program in the first controller that retrieves a first key value from the second controller. The method further includes retrieving a second key value from a table using the first key value as an index value. The table is stored in a memory that is accessible by the first software program. The method includes executing at least one mathematical operation in the first software program using at least the second key value to obtain a third key value. The method further includes sending the first and third key values from the first controller to the second controller. The method further includes determining a first validation value based on the first key value utilizing the second controller. The method further includes comparing the third key value to the first validation value using the second controller and indicating that the first software program has executed until completion when the third key value is equal to the first validation value.