What P0500 means
The engine computer isn't getting a usable vehicle speed signal while the car is clearly moving. Depending on the car, that signal comes from a sensor on the transmission or from the wheel speed sensors through the ABS module, and either is the usual culprit. Expect a dead or jumpy speedometer, no cruise control and sometimes odd shifting.
How the engine computer detects it
The vehicle speed signal A comes, depending on the maker, from a sensor on the transmission, the transmission output speed, the wheel speeds via ABS/ESP or a CAN message; CARB explicitly names it as an input to be monitored. P0500 is the general code for this signal. Ford checks plausibility: the car must be moving (high load, positive torque), yet the signal stays below 1–5 mph for 5 s; Ford diesels flag a missing CAN message after 0.5 s. GM's Saturn ION of 2004 used high load with below 3 mph for 6.2 s (MIL after two trips); GM's 2018 tables use P0502/P0503 instead. Cruise control is then disabled and substitute values are used.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on
- Speedometer dead or jumping
- Cruise control not working
- Automatic shifts harshly or wrongly
Common causes
- ABS/ESP module or wheel speed sensor faulty (signal source) Most likely
- Output speed sensor or vehicle speed sensor faulty or dirty (metal debris on the magnet) Most likely
- Wire or connector open or shorted, corrosion Possible
- CAN communication fault (message missing) Possible
- Wrong tire or axle data programmed Less likely
How to diagnose P0500
- Read the ABS module codes with a scanner that supports ABS. On many cars the speed signal comes from the wheel speed sensors, so a wheel sensor fault can set P0500.
- If your car has a speed sensor on the transmission or transfer case, check its connector and wiring with the ignition off. Remove the sensor and wipe metal debris off its magnetic tip.
- With a scanner and a helper driving, compare vehicle speed with the individual wheel speeds. A reading that's missing or drops out points to that sensor.
- If the tire size or axle ratio was changed, the car's speed calibration may need to be updated with a scanner.
- If all sensors read correctly, a shop checks the network messages and wiring between the ABS, transmission and engine modules.
Vehicles that report P0500 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Infiniti Q50 | 2014–2015 | 11 | — |
Counts of owner complaints to the NHTSA that mention P0500 (33 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 5
- Vehicle speed, idle control and auxiliary inputs
- 00
- Specific fault
Questions drivers ask
Can I drive with code P0500?
You can usually drive it carefully to a shop, but don't trust the speedometer: keep pace with traffic and watch your speed. If the transmission shifts harshly or stays in one gear, avoid highways and drive only to a shop.
Will my car pass an emissions inspection with P0500?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0500 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
Can I fix P0500 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: medium. Start with the cheapest checks before replacing expensive parts.
Often reported together
Codes that owners mention in the same NHTSA complaints as P0500. They can point to a shared cause, so it's worth checking them together.
- P0720Output Shaft Speed Sensor Circuit16 complaints
- P0300Random/Multiple Cylinder Misfire Detected3 complaints
- P1574Manufacturer-specific code3 complaints
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.