Vehicle Speed Sensor: Description and Operation

Vehicle Speed (Distance) Sensor:

This sensor is located in the extension housing of the transaxle, and it generates 8 voltage pulses for every revolution of the axle shaft. These signals are sent directly to the Single Module Engine Controller (SMEC). The SMEC uses these signals along with the signals from the Throttle Position Sensor (TPS) to determine a closed throttle deceleration condition or a closed throttle idle (vehicle stopped) condition.

Under idle (vehicle stopped) conditions, the SMEC sees that there are no signals being generated from the vehicle distance (speed) sensor, and it adjusts the Automatic Idle Speed (AIS) motor to maintain a desired engine idle speed. Under closed throttle deceleration, the SMEC receives signals from the vehicle distance (speed) sensor, because the vehicle is still moving, and it adjusts the AIS motor to maintain a desired Manifold Absolute Pressure (MAP) value.