Vehicle Speed Sensor : Fiat 500 1.4 L 160 hp Gas

What does a Vehicle Speed Sensor do ?

The Vehicle Speed sensor or VSS measures transmission/ transaxle output or wheel speed. The ECM uses this information to modify engine functions such as ignition timing, AF ratio, transmission shift points, and to initiate diagnostic routines.
The Vehicle Speed sensor is typically located at the transmission or transaxle.

Bad vehicle speed sensor affects your vehicle's anti-lock brakes

If your check engine light is on, it could be a problem with your vehicle speed sensor.
 
Your car’s “Check Engine” or “Service Engine Soon” light can flash on for more than 1,400 different reasons, and in the coming months, we’re going to share with you what some of those reasons are. The light is part of your vehicle’s on-board diagnostics (OBD) system and can indicate anything from a quick fix like a loose gas cap to a major repair like a catalytic converter.
 
Trouble code: P0500
This means the vehicle speed sensor is not reading the vehicle's speed correctly.
 
Symptoms of a P0500 IAC Malfunction may include:
- Lossof anti-lock brakes.
- The "anti-lock" or "brake" warning lamps on the dash may be lit (in addition to the check engine light).
- The speedometer or odometer may not work properly (or at all).
- Your vehicle's RPM limiter may be decreased.
- The shifting of an automatic transmission may become erratic.
 
Potential causes of a P0500 code include:
- The vehicle speed sensor is not functioning properly.
- There is a broken/frayed wire leading to the vehicle speed sensor.
- The vehicle's powertrain control module is not correctly configured for the actual tire size on the vehicle.
 
Possible solutions
- Reset the code and see if it comes back.
- Check all wiring and connectors that lead to the speed sensor.
- Check the voltage at the speed sensor.
- If everything looks OK, replace the sensor

How to repair a Vehicle Speed Sensor ?

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.
 

Instructions :
1. 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.
 
2. 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.
 
3. 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.
 
4. 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.
 
5. 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.