P0502: Vehicle Speed Sensor Circuit Low Input

What does P0502 mean?

P0502 is a diagnostic trouble code indicating "Vehicle Speed Sensor Circuit Low Input". The ECU is detecting a voltage reading that is below the expected range in the idle control circuit. This typically points to a wiring short, a faulty sensor, or a grounding issue.

Symptoms you may notice

• Check engine light (MIL) illuminated on dashboard
• Intermittent warning lights
• Erratic gauge readings

Common causes

• Damaged or corroded wiring harness
• Loose or disconnected electrical connector
• Failed idle control sensor or actuator
• Blown fuse in the related circuit
• Poor ground connection

What should you do?

Schedule a diagnostic appointment at your earliest convenience. The vehicle is generally safe to drive short distances, but the underlying issue should be addressed to prevent it from worsening.