Tracking P0446 on Your 2022 Nissan Altima
The P0446 code on your 2022 Altima indicates the ECM has detected a malfunction in the EVAP vent control circuit. On Nissan vehicles, the canister close valve isn't electrically responding as expected. This is a circuit-level fault—the investigation focuses on the valve, its wiring, and connections rather than physical vapor leaks.
Your 2022 Altima is part of the sixth generation (L34) with the 2.5L QR25DE engine and CVT transmission. After three years of daily driving, the canister close valve and its wiring connections are the primary suspects for this circuit code.
Symptoms Under Review
- Check engine light on with P0446 stored
- Fuel pump nozzle clicking off during fill-ups
- EVAP readiness monitor may not complete
- Possible faint fuel smell near the rear
- Normal engine performance and CVT operation
Ranked Causes
For the 2022 Altima, the evidence points to:
- Canister Close Valve Failure (High Likelihood): The primary suspect. Nissan's canister close valve can develop coil failures or valve sticking after a few years of service. Parts: $50–$100, labor: $80–$150.
- Wiring or Connector Corrosion (High Likelihood): Road moisture corrodes the canister close valve connector and wiring over time. Repair: $75–$200.
- Charcoal Canister Contamination (Medium Likelihood): Fuel overfilling pushes liquid gasoline into the canister, affecting vent circuit operation. Replacement: $130–$280.
- Leak Detection Pump Issue (Medium Likelihood): Nissan's unique leak detection pump can affect EVAP circuit diagnosis. A malfunctioning pump may indirectly trigger P0446. Replacement: $150–$300.
- ECM Software Update (Low Likelihood): Nissan may have released updated EVAP monitoring calibrations. A dealer reflash: $80–$150.
Diagnostic Steps
Confirm P0446 with an OBD-II scan. Locate the canister close valve near the charcoal canister at the rear of the Altima. Inspect the connector for corrosion and test valve resistance with a multimeter. Apply 12V to verify the valve actuates. Nissan's CONSULT diagnostic tool provides enhanced testing including bidirectional control. Check for any Nissan TSBs related to the sixth-gen Altima EVAP system.
Warranty Check
Your 2022 Altima may still be within Nissan's 3-year/36,000-mile bumper-to-bumper warranty depending on purchase date and mileage. The federal emissions warranty covers EVAP components for 8 years/80,000 miles through 2030. Verify your coverage before proceeding with out-of-pocket repairs.
Resolution
The P0446 on your 2022 Altima is a common EVAP code with a straightforward resolution. The canister close valve is the most frequent fix. With warranty potentially still active, check with your Nissan dealer first—the repair may be covered. Your sedan's fuel economy, CVT smoothness, and daily comfort remain fully intact.