Is it safe to drive with this code?

Whilst many vehicles remain drivable, you may experience irregular gear changes, inaccurate speedometer readings, and disabled cruise control or ABS functionality; short journeys are typically manageable, but prolonged driving is not advisable—please see our site disclaimer for further guidance.

P0502 may affect your MOT outcome if the malfunction indicator lamp is illuminated at the time of test, or if ABS or traction-control warnings are present; the key factor is whether warning lights are on during the inspection—consult our disclaimer for full details.

Roughly how much does it cost to fix?

Repair costs vary widely depending on the root cause: a sensor replacement alone typically falls in the low two-figure range for parts, plus labour; if wiring repairs are needed, expect low to mid three-figure bills at an independent garage, whilst main-dealer diagnostics or ECM replacement (rarely required) can reach four-figure sums.

Can I clear the code and continue driving?

Clearing the code without repairing the underlying fault means it will typically return once the ECM re-checks the sensor circuit; additionally, driving with inaccurate speed data can impair transmission behaviour and safety systems, so addressing the root cause is advisable.

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← All fault codes | Electrical & Sensors

P0502

Powertrain

Vehicle Speed Sensor A Low Input

The engine control module has detected that the primary vehicle speed sensor is sending a lower voltage signal than expected, often due to sensor or wiring faults.

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ⓘ Information only. This page provides general educational information about fault code P0502. 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 P0502 mean?

P0502 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Vehicle Speed Sensor A Low Input.

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.

About Electrical & Sensors codes

Codes in the Electrical & Sensors category.

P0502 is one of 4,010 codes in this category. Browse all Electrical & Sensors codes →

What we know about P0502 specifically

We record the SAE J2012 standardised definition and the system this code belongs to, but we have not yet published detailed driver-reported symptoms, common causes, or step-by-step diagnostic guidance for P0502.

Rather than invent that information by generating generic content from a template, we leave it out. For specific guidance, the most reliable sources are:

•your vehicle's own service manual or manufacturer-specific technical bulletins
•a qualified mechanic with a manufacturer-level diagnostic tool
•a marque specialist familiar with your make and model

Codes nearby

Codes adjacent to P0502 in the P-code series. Many fault codes appear together with their neighbours because they relate to the same circuit or component.

P04AA Exhaust Pressure Control Valve B Position Sensor/Switch Circuit Intermittent

P0500 Timing Belt Skipped One Tooth Or More

P0501 Vehicle Speed Sensor "A" Range/Performance

P0503 Vehicle Speed Sensor A Intermittent

P0504 Brake Switch A/B Correlation

P0508 Idle Air Control Circuit Low

Other Electrical & Sensors codes

Other fault codes in the same system as P0502. The ones with detailed guides have plain-English explanations, symptoms, causes, and diagnostic steps.

B1257

Air Temperature External Sensor Circuit Short To Ground Detailed guide

B1363

DBPT Circuit Short To Ground Detailed guide

B2100

Ignition Run/Start Input Circuit Performance Detailed guide

C2000

Steering Angle Sensor Not Calibrated Detailed guide

P0030

HO2S Heater Control Circuit (Bank 1 Sensor 1) Detailed guide

P0031

Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1) Detailed guide

Spotted an issue or have something to add? Mechanics, technicians, and drivers who have first-hand experience with P0502 can submit a correction or expansion. We review every submission before publishing, mechanic submissions are prioritised.

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 →

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