P0447 means the ECU detected an open electrical circuit on the EVAP vent control valve. The vent valve seals the charcoal canister during EVAP system testing. An open circuit usually points to a broken wire, a corroded connector, or a failed solenoid coil inside the valve itself.
DTC/P0447·Audi
P0447 on Audi: Causes, Symptoms and Fix Cost
Quick Answer
Low SeveritySafe to drive (short-term)Audi
P0447 on a Audi means the ECU detected an open electrical circuit on the EVAP vent control valve. The vent valve seals the charcoal canister during EVAP system testing. An open circuit usually points to a broken wire, a corroded connector, or a failed solenoid coil inside the valve itself.
Repair cost on Audi€63 - €750
What does P0447 mean on a Audi?
Audi A4
2005–2024The B7 and B8 A4 share EVAP components with the VW Golf. The N115 vent valve on the canister is the typical failure for P0447. Audi part availability is good through ATU, Autodoc.de, and kfzteile24.de, with aftermarket valves around 40 to 60 EUR.
What causes P0447 on a Audi?
Beyond the generic causes listed on the main P0447 page, these are the Audi-specific patterns we see most often:
Audi A4N115 vent valve failure on B7/B8
Audi A4Harness chafing where it crosses the rear subframe
How to diagnose P0447 on a Audi with OBD2
Follow these steps to pinpoint the root cause of P0447:
- Locate the vent valve. On most vehicles it is bolted to the charcoal canister near the rear axle or fuel tank. Inspect the connector for corrosion, road salt damage, or a loose lock
- Disconnect the valve and measure solenoid resistance with a multimeter. Expect 20 to 35 ohms on most designs. An infinite reading confirms an open coil and a failed valve
- With the connector unplugged, back-probe the harness side and check for 12V on the supply pin (key on, engine off). No voltage means a wiring fault between the ECU and the valve
- Inspect the wiring from the ECU to the vent valve for chafing, rodent damage, or breaks. The harness often runs along the underbody and is exposed to road debris
- Use a scan tool to command the vent valve on and off. Listen for a clear click. If the valve is silent and resistance is in spec, suspect a wiring or ECU fault
How much does P0447 cost to fix on a Audi? (EUR)
Estimated repair costs on a Audi (Audi parts and labour typically run 25% above the average for this code).
Prices estimated as of May 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0447 on Audi
These codes commonly cluster with P0447 on Audi vehicles:
FAQ: P0447 on Audi
Will P0447 cause my car to fail emissions?
Yes. The check engine light will cause an automatic fail at any EU vehicle inspection (TÜV, ITV, TA, SKP). The vent valve is a monitored component, so the ECU will not run the EVAP readiness test until the circuit is fixed.
Can I drive with P0447?
Yes, the code does not affect engine performance, fuel economy, or safety. The only practical impact is the check engine light and the failed emissions test. Repair within a few weeks to avoid related EVAP codes piling up.
Is it always the vent valve, or could it be the wiring?
About 60 to 70 percent of P0447 cases are a failed solenoid coil inside the vent valve itself. The remaining cases are wiring damage, especially on vehicles where the valve is mounted underbody and exposed to road salt and debris. Always measure resistance before replacing the valve.
How much does a P0447 repair cost?
A new vent valve runs 40 to 150 EUR in parts plus 30 to 80 EUR labour, for a total of 70 to 230 EUR. Wiring repairs are typically 50 to 160 EUR. If the canister-mounted valve is integrated and not separately serviceable, expect 180 to 600 EUR for the full canister assembly.
Looking for the full P0447 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0447 guideSkanyx · Audi
Diagnosing P0447 on your Audi?
Connect any Bluetooth OBD2 adapter, scan for codes, and get AI-powered diagnostics with severity ratings and repair cost estimates.
Download Skanyx