Unraveling the P0446 Mystery on Your 2020 Nissan Murano
Your 2020 Nissan Murano has presented a diagnostic puzzle: a P0446 code pointing to a malfunction in the EVAP vent control circuit. This third-generation Murano (Z52 platform) shares its 3.5L VQ35DE V6 across the Nissan crossover lineup, and that means it also shares common EVAP failure patterns. The PCM has detected that the canister close valve's circuit isn't responding correctly — an electrical issue rather than a physical vapor leak.
The Murano's unibody crossover design keeps EVAP components reasonably protected, but five years of service life gives corrosion and wear enough time to affect electrical connections. Let's trace the evidence to the source.
Symptoms You've Likely Noticed
- Check engine light on with P0446 code stored
- Fuel pump nozzle shutting off repeatedly during fill-ups
- Occasional fuel vapor odor near the vehicle's rear
- EVAP readiness monitor failing to complete
- Possible companion codes like P0440 or P0456
Top Suspects in This Investigation
- Canister Close Valve Failure (High Likelihood): The canister close valve on the Murano is located near the charcoal canister toward the rear. Electrical failure from age and heat cycling is the leading cause. The VQ35DE shares EVAP components with the Altima, Maxima, and Pathfinder, and this valve is a known weak point across all of them. Parts $55–$110, labor $120–$220.
- Wiring or Connector Corrosion (High Likelihood): Road salt, moisture, and five years of exposure degrade the connector terminals and wiring insulation at the canister close valve. This is especially common in northern climates. Repair costs $100–$300.
- Leak Detection Pump Circuit Fault (Medium Likelihood): Nissan's unique leak detection pump works alongside the vent circuit. An electrical fault in this pump or its wiring can cause P0446. Replacement runs $150–$350.
- Charcoal Canister Saturation (Medium Likelihood): Repeatedly topping off the fuel tank can push liquid fuel into the charcoal canister, saturating it and affecting vent system operation. Canister replacement costs $200–$400.
- PCM or Ground Fault (Low Likelihood): A poor ground at the PCM or vent circuit can create intermittent P0446 codes. Diagnosis and repair costs $100–$250.
Step-by-Step Diagnosis
- Retrieve all stored and pending codes with a quality OBD-II scanner
- Locate the canister close valve near the charcoal canister under the rear of the vehicle
- Inspect the valve's electrical connector for corrosion, water intrusion, or damage
- Test canister close valve solenoid resistance against Nissan specifications
- Apply 12V to the valve to verify it clicks and operates
- Trace the wiring harness from the valve to the PCM, checking for damage
- Test the leak detection pump if vent-side components check out
Cost Breakdown
- Canister close valve replacement: $175–$330
- Connector/wiring repair: $100–$300
- Leak detection pump: $150–$350
- Charcoal canister: $200–$400
- Diagnostic fee: $80–$150
Can I Drive With P0446?
Yes. P0446 is strictly an emissions circuit code. Your Murano's V6 engine and CVT transmission will operate normally. There's no safety risk. However, the code will prevent you from passing an emissions inspection.
DIY vs. Professional
Your 2020 Murano is past the 3-year/36,000-mile basic warranty, but check your mileage against the 8-year/80,000-mile federal emissions warranty — EVAP components are covered. For DIY repairs, the canister close valve is moderately accessible on the Murano. You'll need a multimeter for electrical testing and basic hand tools for replacement.