Vehicle Speed Sensor (VSS)

VSS is mounted in transmission/transaxle. The VSS generates electrical pulses when vehicle is in motion. The electrical pulses are sent to the ECA where they are translated and used to compute vehicle speed. The ECA interprets VSS input along with throttle position sensor input.

ECA differentiates between closed throttle deceleration and closed throttle idle (vehicle stopped) conditions. During deceleration, ECA controls By-Pass Air Control (BAC) valve to maintain a desired manifold pressure value. During idle (vehicle stopped), ECA controls Idle Speed Control (ISC) motor to maintain a correct idle speed.