Vehicle Speed Sensor: Description and Operation

Vehicle Distance (Speed) Sensor:

LOCATION

The vehicle speed sensor, mounted on the right side of the transaxle.


FUNCTION

Sensor is used to inform engine controller of vehicle speed, vehicle acceleration, or deceleration.


OPERATION

Sensor generates 8 voltage pulses per axle shaft revolution (sent directly to engine controller).

Engine controller uses sensor input with input from Throttle Position Sensor (TPS) to determine closed throttle deceleration or closed throttle idle (vehicle stopped).

During idle, (no signals being received from sensor), engine controller actuates Automatic Idle Speed (AIS) motor to maintain desired engine idle speed.

During closed throttle deceleration, (slower signals received from sensor), engine controller actuates AIS motor to maintain desired Manifold Absolute Pressure (MAP) sensor value.

The vehicle distance (speed) sensor input signal is also used as a mileage reference for the Emissions Maintenance Reminder Light (EMR), and also to maintain speed control operation.