| 摘要 |
PURPOSE:To provide an idle speed control device for engine to display a fail- safe function in fail due to breakage and shortage of power circuit, and eliminate an extremely excessive and short engine intake air in fail. CONSTITUTION:An idle speed control device includes first and second branch passages 13 and 14 in a bypass passage 10, a first ISC valve 21 provided in the first branch passage 13, a second ISC valve 22 provided in the second branch passage 14, a control unit ECU to control the operation of the first and second ISC valves, and a power control circuit for ISC valve connected to the control unit. For the first ISC valve, a normally closed valve to close in non-energized condition is used and, for the second ISC valve, a normally-open valve to open in non-energized condition is used. |
