Vehicle Speed Sensor
NOTE:
On models equipped with 4-speed A/T, Output Speed Sensor (OSS) supplies vehicle speed and distance inputs to PCM through Transmission Control Module (TCM). See OUTPUT SPEED SENSOR
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On models equipped with M/T, Neon and some A/T equipped models, VSS generates a predetermined number of pulses per sensor revolution (4 pulses per revolution on some models, or 8 pulses per revolution on other models). VSS input is used by ECM/PCM to determine vehicle speed and distance traveled.
Speed and distance inputs along with TP sensor closed throttle input, determine if a closed throttle deceleration or normal throttle idle (vehicle stopped) condition exists. During deceleration, ECM/PCM controls IAC motor to maintain a desired MAP value. During idle (vehicle stopped), ECM/PCM controls IAC motor to maintain a desired idle speed.