The P0500 diagnostic trouble code (DTC) indicates a malfunction with the vehicle speed sensor (VSS). While a faulty vehicle speed sensor isn’t likely to cause damage to your engine, it can make driving difficult. A lot of safety features found in modern cars rely on VSS to operate properly. Problems with the vehicle speed sensor are most hazardous when driving on wet or icy roads.
Let’s dive into what P0500 means, what typically causes it, and the best methods for fixing it.
What Does Error Code P0500 Indicate?
The data from the VSS is displayed on the speedometer on the vehicle dash. It’s also shared with the transmission system, power steering, and anti-lock brake system (ABS system), so malfunctions in this sensor can have wide-ranging effects.
Other trouble codes related to the speed sensor include P0501, P0502, and P0503. You may see one or more of these codes along with P0500, especially if the sensor itself is malfunctioning.
What Is The Vehicle Speed Sensor (VSS)?
The vehicle speed sensor (VSS) is how your car knows how fast it’s currently traveling. To help the vehicle maintain optimal operation, the VSS sends data to the powertrain control module (PCM) or engine control module (ECM, also known as the engine control unit (ECU).
The VSS is an electromagnetic sensor, traditionally mounted on the transmission housing. A reluctor ring attached to the transmission shaft passes the tip of the VSS on each rotation. These interruptions to the circuit are translated into the vehicle speed and output to the ECM or PCM.
The exact location of the VSS varies widely between manufacturers. It’s typically found on or near the transmission system on rear-wheel-drive vehicles. It may also be located inside a wheel well or attached to the speedometer. In many modern engines, there is a speed sensor on each wheel. Check your manual before you start making repairs to find out the configuration of your engine.
Troubleshooting: What are the symptoms of the P0500 code?
There are often no noticeable drivability symptoms with P0500 aside from erratic speedometer readings. The extent of issues largely depends on how your engine’s systems use the data from the vehicle speed sensor. Common symptoms include:
- Activation of the check engine light
- Activation of ABS dash warning light
- Speedometer or odometer not working properly
- Disabling of ABS or traction control systems
- Difficulty shifting or erratic shifting from the automatic transmission
What Are The Possible Causes Of The P0500 Error Code?
Since vehicle speed sensors are not standard across the automotive industry, causes of the P0500 error code can vary from car to car. Usually, a code PO500 shows up when there is no signal between the vehicle speed sensor.
Common causes include:
- Faulty vehicle speed sensor
- Faulty speedometer
- Damaged or loose wires around VSS
- Opens or shorts in wiring harness
- Damaged electrical connections
- Damage to drive gear
- Communication issues in the engine computer
- PCM or ECM not configured to current tire size
Avoiding P0500 Codes: What To Do After Replacing Your Tires
The most preventable cause of the P0500 code is a failure to reprogram the ECM or PCM after replacing the tires. Even a small change in tire diameter can cause erratic readings from the vehicle speed sensor. While some OBD2 scanners allow you to make these modifications yourself, in most cases you’ll want to take your vehicle to a mechanic to have the computer re-configured after replacing your tires
How serious is the P0500 code?
The P0500 code is of moderate severity. Your ability to drive won’t be impeded while this code is active, but the vehicle may have difficulty shifting or can lose crucial safety systems like anti-lock brakes and traction control. In addition, it will be difficult to maintain proper driving speed without a functional speedometer. You should take care of driving your vehicle with a P0500 code active, especially in rainy or wintery weather.
VSS Repair: Diagnosing And Clearing A P0500 Code
Tools you’ll need:
- OBDii scan tool
- Digital multimeter
- Check for any technical service bulletins related to the P0500 code for your vehicle. There are known fixes for this problem for many vehicles, most notably Toyotas. Following suggestions for your specific make and model can greatly speed the diagnostic process.
- If you’ve recently replaced your tires, verify that they are the same size that you had on the vehicle before. Different sized tires rotate at different speeds relative to the engine speed, and your engine computer needs to be updated to compensate. Take your vehicle to a mechanic to have your ECM or PCM configured correctly for the actual size of the tires on your vehicle.
- Use an OBD2 scanner to read all trouble codes and look at the freeze frame data. Check the readings from the VSS for the most recent drive cycle. If the signal is intermittent, there is likely a wiring issue.
- Visually inspect the wires around the VSS and speedometer. Replace any that are frayed or otherwise damaged, and make sure all connections are clean and secure. If you made any repairs or adjustments, clear the code and re-scan.
- If the VSS readings are erratic but you found no damaged wires, use a multimeter to test each wire for internal shorts or open circuits.
- Use a multimeter to test the voltage of the vehicle speed sensor. Compare the readings to the specifications in your repair manual and replace it if necessary.
- Malfunctions in other electronic components, such as the speedometer, can interrupt communication between the VSS and the engine computer. A mechanic can verify if this is the case by checking the sensor waveform and making the necessary repairs.
VSS Repair vs. Speedometer Repair
The most preventable cause of the P0500 code is a failure to reprogram the ECM or PCM after replacing the tires. Even a small change in tire diameter can cause erratic readings from the vehicle speed sensor. While some OBD2 scanners allow you to make these modifications yourself, in most cases you’ll want to take your vehicle to a mechanic to have the computer re-configured after replacing your tires.