Vehicle Speed Sensor

Vehicle Speed Sensor:

LOCATION
The speed sensor is located in the transmission extension housing.

PURPOSE
The sensor input is used by the Powertrain Control Module (PCM) to determine vehicle speed and distance traveled.

OPERATION
The speed sensor generates 8 pulses per sensor revolution. These signals, in conjunction with a closed throttle signal from the throttle position sensor (auto. trans. only), indicate a closed throttle deceleration to the PCM. When the vehicle is stopped at idle, a closed throttle signal is received by the PCM (but a speed sensor signal is not received).

In addition to determining distance and vehicle speed, the output from the sensor is used to help control:

Speed control operation
Transmission overdrive operation
Transmission torque converter electrical operation