The evaporative emissions control (EVAP system) prevents fuel vapours escaping into atmosphere. Carbon pellets are used to absorb and store fuel vapours. Engine control module (ECM/PCM/ECU) continuously monitors the ventilation control valve. The ECU opens the ventilation control valve when conditions are ideal. Fuel vapours in the canister will be sent to the engine for burning. The ECU will generate the P0446 error code if it detects a fault in the ventilation control. It will also illuminate the check engine light.
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What are the Symptoms of Error Code P0446?
- Fuel consumption increases slightly
- Check engine light is illuminated
- Petrol smell
What causes the P0446 fault code?
- Fuel tank cap broken, defective, damaged, or loose (most common).
- Fuel tank cap housings that are cracked, broken or damaged
- Leakage in the EVAP System Line or Hoses
- Carbon canister broken or damaged
- Fuel tank that is faulty or damaged
- Open or short circuited electrical connections
How to Fix Fault Code P0446?
The ventilation valve is the only symptom that may help you identify the problem. A qualified technician should check the system for any open circuits or short circuits. If the problem persists, the ECU/PCM or vapour relief valve may need to be replaced. The dashboard engine fault light should be turned off if you fix the evaporator vent valve. If the P0446 code persists, it may be necessary to replace other components. If P0441 and P0440 are also present, there may be a leak in the EVAP or a solenoid.
Check if the cap on your fuel tank is damaged or loose. If the cap is loose, you can tighten it to clear the code. Check the fuel tank cap to see if it has any physical damage. Some faults may not be visible. Just in case, replace the cap and reset the code. Fuel caps can be inexpensive and often solve the P0446 error code.
- Replace the fuel tank cap
- Repairing the fuel tank or replacing it
- Replace the canister
- Replace the EVAP lines
How Serious is Fault Code P0446?
The P0446 engine fault light does not affect your vehicle’s performance. The engine fault light is the only symptom you will experience. The warning light should be turned off, but the fault still needs to be repaired and diagnosed.
