Abstract: A method for pulse width modulating a resistance element of an oxygen sensor. The method quickly heats the resistance element of the oxygen sensor soon after start of the engine with a relatively high duty cycle yielding wide pulse widths. During a mid oxygen sensor temperature range, the method decreasing the duty cycle and thereby the pulse width modulation. And, upon the oxygen sensor reaching peak operating temperature range, the method decreases the pulse width modulated voltage signal supplied to the oxygen sensor to relatively short duty cycled pulses.

Abstract: A method of altitude compensation of exhaust gas recirculation in an intake manifold for an internal combustion engine includes the steps of calculating vacuum at sea level, calculating vacuum at present altitude of the engine, determining whether the calculated vacuum at sea level is equal to the calculated vacuum at present altitude, and correcting the exhaust gas recirculation in the intake manifold if the calculated vacuum at sea level does not equal the calculated vacuum at present altitude.

Abstract: A method of estimating exhaust gas recirculation in an intake manifold for an internal combustion engine includes the steps of determining a volumetric efficiency value of the intake manifold, determining whether a speed of the engine is accelerating, getting a manifold unfilling constant if the speed of the engine is not accelerating, getting a manifold filling constant if the speed of the engine is accelerating, calculating a K-factor based on the volumetric efficiency value and either the manifold filling constant or manifold unfilling constant, and using the K-factor to modify spark of the engine.

Abstract: An integrated-circuit power-on reset arrangement which starts in a known state due to transistor sizing and to a current mirror circuit at least initially holding a bistable circuit in a predetermined one of its states.