What does code P0499 mean?

Q: What does code P0499 mean?

Evaporative Emission System Vent Valve Control Circuit High. P0499 means the powertrain control module (PCM) commanded the evaporative emission (EVAP) system vent valve to open or close, but the voltage on the valve's control circuit stayed higher than expected. The PCM monitors the vent valve circuit for a short to voltage or an open ground path, and it sets this code when the feedback voltage does not drop when the valve is energized.

DTC codes / P04xx · Auxiliary emission controls / P0499

P0499Evaporative Emission System Vent Valve Control Circuit High

P0499 means the powertrain control module (PCM) commanded the evaporative emission (EVAP) system vent valve to open or close, but the voltage on the valve's control circuit stayed higher than expected. The PCM monitors the vent valve circuit for a short to voltage or an open ground path, and it sets this code when the feedback voltage does not drop when the valve is energized.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaAuxiliary emission controls

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.