Things You'll Need
Your vehicle comes equipped with a speed sensor. The speed sensor monitors the transmission rotation and sends this information to the engine computer, which then controls the speedometer appropriately. When the speed sensor fails you must replace it for the speedometer to work correctly. This will ensure you always know the correct speed you are traveling.
Park the vehicle on a level surface. Engage the emergency brake and turn the engine off. If the vehicle was recently driven, allow a half hour for the components to cool.
Place a vehicle jack on the left side and right side of the automobile. Raise the jacks until there is enough room for you to comfortably slide under the vehicle. Slide under the vehicle with your back to the ground.
Look straight up on the passenger side of the vehicle. You will see the transmission. The speed sensor is on the right side of the transmission. Look for a small plug-type component coming out from the side. The speed sensor is about 3 inches in length and has an electrical connector coming straight off of it.
Unplug the electrical wire. Pull the base of the wire connector straight out of the plug. You will now have clear access to the bolt that secures the sensor in place. Remove the bolt using a wrench. Unscrew the sensor by turning it counterclockwise. Discard the sensor.
Align the replacement speed sensor into the transmission. Screw the component clockwise to tighten. Replace the bolt and tighten it to secure the sensor. Plug the electrical base into the new sensor until you hear it click. Slide out from under the vehicle and lower the jacks.