| 摘要 |
PURPOSE:To make it possible to determine whether a running engine is connected to a 25 pulse car speed sensor or a 4 pulse car speed sensor by selecting and connnecting a connection terminal of a control unit according to the type of vehicle speed sensors. CONSTITUTION:When a 25 pulse vehicle speed sensor is connected to a D terminal, signals are inputted from the terminal and the output from the collector side of a transistor 70F provides a power source voltage Vcc as intact. Therefore, a CPU102 searches to discover that the 25 pulse vehicle speed sensor is connected by where or not outputs from a B terminal inverts in signals after a given time passes. When a 4 pulse vehicle speed sensor is connected to an E terminal, 4 pulse signals are outputted from the B terminal. At this time, the outputs of the B terminal inverts in signal at a fixed cycle, which enables the searching to indicate that the 4 pulse vehicle speed sensor is connected. This makes it possible to determine whether a running vehicle is connected to the 25 pulse vehicle speed sensor or the 4 pulse vehicle speed sensor is connected. |
