P0500
PowertrainTiming Belt Skipped One Tooth Or More
The vehicle speed sensor (VSS) signal is missing or unreliable. The ECU isn't getting the speed information it needs from the speed sensor, which is usually mounted on the gearbox output or the wheels (depending on the car).
ⓘ Information only. This page provides general educational information about fault code P0500. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0500 mean?
P0500 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Timing Belt Skipped One Tooth Or More.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Speedometer not working or reading erratically
- • Engine warning light
- • ABS warning light, on cars where the ABS shares wheel speed sensors
- • Cruise control disabled, the system requires a working speed signal
- • Possibly rough shifting on automatics, which use speed for shift timing
- • Sometimes higher-than-normal idle speed (the ECU uses speed to set idle behaviour)
Possible causes
Causes commonly associated with P0500, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Failed vehicle speed sensor (most common cause)
- 2. Damaged or unplugged sensor connector
- 3. Wiring damage between sensor and ECU, often from chafing or corrosion
- 4. Damaged tone ring or reluctor wheel that the sensor reads
- 5. On cars that use ABS wheel sensors for speed: a wheel sensor or wiring fault feeding back into the ECU
- 6. Failed speedometer cable on older cars with mechanical speedos
- 7. Software issue requiring update on certain model years
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Check the speedometer first, does it work at all? An intermittent or zero reading helps narrow the fault
- 2. Inspect the VSS and connector, the sensor is usually on the gearbox output or differential
- 3. On cars with ABS-derived speed signals: scan all four ABS wheel speed sensors and look for the one that's offline
- 4. Test the sensor electrically against spec, sensors typically read 200-2,000 ohms depending on type
- 5. Check wiring continuity from sensor to ECU using a multimeter on continuity setting
- 6. If the sensor and wiring are healthy, the ECU input may be at fault
Common questions about P0500
Will my MOT pass? +
Code itself doesn't fail MOT, but a non-working speedometer is an automatic MOT failure. Get this fixed before the test, not after. Also, if engine warning light is on at the time of test, that's an automatic fail post-2018.
Could a recent gearbox change have caused this? +
Possibly. After gearbox work, the VSS or its connector may have been disturbed and not properly refitted. Check the connector first if P0500 appeared shortly after a workshop visit involving the gearbox.
Is the car safe to drive without a speedo? +
Legally questionable, the speedo not working is an MOT fail and you're effectively driving without knowing your speed, which can lead to speeding offences. Most drivers can manage a short drive to a garage but it's not safe long-term, fix promptly.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →