P0500
Vehicle Speed Sensor A Circuit
Vehicle speed sensing
Generic OBD-II
High
What it means
P0500 means the ECM isn't getting a valid vehicle-speed signal. The engine still runs, but that signal drives the speedometer, cruise control, and transmission shift timing, so those systems can act up. Most often the speed sensor or its wiring has failed; check the sensor and connector before replacing anything else.
High
Can I keep driving? Usually yes — the engine runs fine, but the speedometer, cruise control, and transmission shifts can misbehave, so drive with extra caution.
Common symptoms
What you'll notice
- Check-engine light on
- Speedometer reads zero, wrong, or erratic
- Harsh, delayed, or erratic transmission shifting
- Cruise control won't engage
Common causes
Most likely first
- Failed vehicle speed sensor (or wheel-speed/output-shaft sensor feeding it) — most commonLikely
- Damaged, corroded, or loose wiring/connector in the sensor circuitCommon
- Damaged sensor tone/reluctor ringCommon
- Faulty ECM or instrument-cluster input (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the speed reading is dropping to zero or reading erratically while moving.
- Locate the speed sensor (commonly on the transmission or transfer case) and inspect its connector and wiring.
- Check the sensor tip for metal debris and inspect the tone ring it reads.
- Test the sensor's signal output and its power/ground against spec; replace the sensor if out of range.
- If the sensor and wiring are good, check the ECM input. Clear and road-test.
FAQ
Quick answers
Is it safe to drive with P0500?+
The engine runs, but a dead speedometer and confused transmission shifting make it less safe. Drive carefully and get it fixed soon, especially on an automatic.
Can I just clear P0500?+
It comes back once the speed signal drops out again. Repair the sensor or wiring first.
Related codes
Often seen with P0500
Read & clear P0500 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX