Abstract: The present invention provides an apparatus for limiting the occurrence of knock conditions in an internal combustion engine. The apparatus includes a throttle sensor that detects transition of an engine throttle from a steady state throttle condition to a wide open throttle condition. Further, spark means is provided for generating a spark for an engine cylinder firing event, with the spark means generating the spark with an associated spark advance. Further, a controller is provided that is responsive to the wide open throttle condition detected by the throttle sensor and that causes the spark advance to incrementally advance to a maximum level over a predetermined time period, thereby minimizing the occurrence of engine knock conditions.

Abstract: The status of a Park/Neutral (P/N) switch for an automatic transmission in an automotive vehicle is diagnosed by a method which includes the steps of determining whether an engine of the automotive vehicle is cranking, diagnosing the P/N switch for a P/N state of the automatic transmission when the engine is cranking, and diagnosing the P/N switch for a Drive state of the automatic transmission when the engine is not cranking.

Abstract: Speed error is calculated by finding the difference between set speed and vehicle speed and then filtering the result. During the calculation, cable length must be compensated for in the vehicle electronic speed control system. This compensation enables a more accurate control of the electronic speed control system.

Abstract: A method to disengage an electronic speed control as a function of the condition of the park/neutral gear or manual clutch. If the automatic transmission lever is bumped from "drive" or the manual transmission clutch is depressed while the electronic speed control is operating, the method will sense this by detecting a difference in the ratio of engine speed to vehicle speed. If the ratio changes by .+-.25 percent, the electronic speed control is disengaged.