P0500: Vehicle Speed Sensor "A"

What does P0500 mean?

The vehicle speed sensor (VSS) tells the engine and transmission computers how fast the car is going. That signal can be used for the speedometer, shift timing and other systems.

P0500 sets when the speed signal is missing, erratic or does not match what the ECM expects while the car is moving.

Common symptoms

• Check engine light on
• Speedometer not working or erratic
• Harsh or incorrect shifting on automatic transmissions
• ABS or traction control warning lights on some vehicles

Common causes

The causes below are the ones commonly seen with P0500. The actual cause can vary by vehicle, engine and mileage, so treat this list as a starting point, not a diagnosis.

• A faulty vehicle speed sensor
• Damaged wiring or a poor connection at the sensor

What to check with a scanner

• In Live data, watch vehicle speed while driving safely. Compare it with GPS speed on your phone.
• Inspect the sensor connector and wiring.
• Check for related ABS or transmission codes, since some vehicles share speed signals between modules.
• Check for manufacturer service bulletins for your vehicle.

How to read and clear P0500 with OBD Master Pro

1. Plug in your adapter. Connect a generic ELM327 (or ELM329) OBD2 adapter to the diagnostic port, usually under the dashboard on the driver's side. Bluetooth Classic, Bluetooth LE, Wi-Fi and USB OTG adapters are supported.
2. Switch the ignition on. Turn the key to ON or start the engine, depending on your car.
3. Connect in OBD Master Pro. Open the app, go to Connection and pick your adapter. Classic Bluetooth adapters connect from the Bluetooth tab, Bluetooth LE adapters from the BLE tab with no pairing needed. Use the generic OBD2 / EOBD profile or your car's brand profile.
4. Read the codes. Open the fault codes screen to see stored, pending and permanent codes. Confirm P0500 is listed and note any other codes, since they often explain the cause.
5. Check the details. Look at freeze frame data, Live data and, where your car supports it, Mode 06 test results (see the checks above).
6. Fix, then clear. After the repair, clear the codes to turn off the check engine light. Clearing also resets the emissions readiness monitors, so drive normally and check the readiness screen before any inspection. Permanent codes cannot be erased with a scan tool; they clear on their own once the car's self test passes.

Tip: you can also look up P0500 and other codes in the app's DTC search without connecting to a car. If your adapter will not connect, use Connection > Share connection log and email it to support. Many cheap ELM327 clones only handle basic engine OBD2, which is all you need for P0500.

When to see a mechanic

Get professional help if any of these apply:

• The car shifts badly or ABS warning lights are on
• The code returns after checking the wiring
• Several modules report speed related codes

If you are unsure, a qualified technician can confirm the cause with tests such as smoke testing, pressure testing or scope readings. Clearing a code does not repair the fault.

Related trouble codes

See all OBD2 trouble code guides

Related guides

Check engine light on: what to do · How to read an OBD2 code (P, B, C, U) · Stored, pending and permanent codes and freeze frame · OBD2 readiness monitors explained · OBD2 glossary · OBD2 by car brand