There are hundreds of components inside a car, and when one fails, the onboard computer will let the driver or mechanic know which component may be the root of the problem by setting an error code. If the powertrain control module (PCM) detects an anomaly in any of the vehicle’s systems, it triggers a code that can be used for diagnosing the issue.
Do you have a P0500 code on your hands? Read this guide to learn its definition, causes, and symptoms.
What Does the P0500 Code Mean?
Diagnostic trouble code (DTC) P0500 stands for “Vehicle Speed Sensor (VSS) Malfunction.” This code is set when the PCM or engine control module (ECM) detects incorrect speed readings or no signal at all from the vehicle speed sensor (VSS).
Other names for this code include:
- Vehicle Speed Sensor “A” Range/Performance
- Vehicle Speed Sensor “A” Intermittent/Erratic/High
- Vehicle Speed Sensor “A” Low Input
A vehicle’s speed is projected on the speedometer found on the instrument cluster at the driver’s side of the dashboard. For the speedometer to project an accurate reading of how fast or slow a car is traveling, the PCM has to have enough data from the VSS.
The sensor generates signals when the vehicle is in motion. The PCM computes the vehicle’s speed by counting these pulses.
There are different types of speed sensors, and the process of reading travel speed may vary. Some sensors use magnets, while others make use of light. Regardless of the type, the most common speed sensors use a reluctor ring that is attached to the transmission shaft and passes the tip of the speed sensor on every rotation.
Every time the ring passes the tip, interruptions and completions are made for every notch and groove.
The interruptions are transformed into voltage charges that are sent to the PCM, which then calculates the actual speed and displays it on the speedometer. However, it doesn’t just stop there—the data is also passed on to the transmission system, anti-lock braking system (ABS), power steering, and cruise control.
The data from the speed sensor is vital as it’s used by more than one system in a car.
What are the Possible Causes of the P0500 Code?
As mentioned, speed sensors vary in type. This could mean that the causes may also differ as to the VSS mechanism. Here are the common causes that trigger code P0500:
- Defective vehicle speed sensor
- Problem with the PCM
- Short or open wire leading to VSS
- PCM not configured for the tire size being used
- Damaged drive gear
What are the Common Symptoms of the P0500 Code?
Below are the common symptoms you may face if your OBD-II scan tool is showing the P0500 code:
- Malfunctioning speedometer
- Problem shifting gears, especially in an automatic transmission
- Inactive or erratic ABS performance
- Inaccurate RPM reading
- Traction control not engaging
How to Diagnose the P0500 Code
It might be difficult to figure out what exactly triggered the P0500 code, which is why people often leave the diagnosis to a mechanic. If you feel confident enough in your DIY auto repair skills, however, you can probably pinpoint the cause by following the videos below:
How to Fix the P0500 Code
Since there are several possible causes that could trigger the P0500 code, there’s no single way to fix it. Because of this, you’re probably better off having a professional mechanic fix your car for you.
Of course, you can decide to resolve the P0500 code on your own if you have the necessary DIY skills. As discussed above, you’ll first need to diagnose the problem before you can fix it. You can check repair manuals and online auto repair resources and guides to help make sure you’re on the right track.
You can also invest in an ALLDATA single-vehicle subscription, which should be useful not just for this repair but for other future fixes you may need to do on your car.
Always remember that different carmakers have their own specific repair instructions for their vehicles, so what works for one model may not work for a different one. Make sure to consult your repair manual before working on your car.