P0499: Evaporative Emission System Vent Control Circuit High

MediumPowertrainEVAP System

What does P0499 mean?

P0499 is a diagnostic trouble code indicating "Evaporative Emission System Vent Control Circuit High". The ECU is reading a voltage that is above the expected range. This can be caused by a short to power in the wiring, a failed sensor, or a connector issue in the evap system.

Symptoms you may notice

  • Check engine light (MIL) illuminated on dashboard
  • Fuel smell near the vehicle
  • Difficulty filling fuel tank
  • Intermittent warning lights
  • Erratic gauge readings

Estimated repair cost

Typical range in Australia (parts + labour)

$100 – $400 AUD

Common causes

  • Damaged or corroded wiring harness
  • Loose or disconnected electrical connector
  • Failed evap system 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.

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Code P0499 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.

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Related codes

P0498Evaporative Emission System Vent Control Circuit Low
P0497Evaporative Emission System Low Purge Flow
P0496Evaporative Emission System High Purge Flow
P0469Evaporative Emission System Purge Control Valve Circuit High / Purge Flow Sensor Circuit Intermittent