Secondary air pump control system for internal combustion engines

摘要

A secondary air pump control system for an internal combustion engine having an air pump for supplying secondary air to the exhaust passage, comprises a voltage detector for detecting voltage applied to the air pump, a current detector for detecting current flowing through the air pump, and a switch for making a changeover between supply of electric power to the air pump and cutoff of same. The flow rate of secondary air supplied by the air pump is detected based on an output from the voltage detector and an output from the current detector. The operation of the switch is controlled based on the flow rate thus detected.