US Patent 7464695 Throttle body restriction indicator

A control system for a vehicle comprises a throttle control module and a diagnostic module. The throttle control module controls a position of a throttle of the vehicle and compensates for changes in effective opening area of the throttle due to coking. The diagnostic module reports a coking value to a user based upon an amount of compensation performed by the throttle control module. A method comprises controlling a position of a throttle of a vehicle; compensating for changes in effective opening area of the throttle due to coking; and reporting a coking value to a user based upon an amount of compensation performed.