Investigating P0446 on Your 2020 Chevrolet Traverse
A P0446 code on your 2020 Traverse means the PCM has identified an electrical fault in the EVAP vent control circuit. The vent valve solenoid isn't performing as the PCM commands—this is a circuit-level malfunction that calls for electrical troubleshooting rather than searching for vapor leaks.
The 2020 Traverse rides on GM's C1XX platform with a 3.6L V6 engine, offering three rows of seating and family-oriented versatility. After five years of service, the EVAP system's vent valve solenoid and its connections are the most probable source of this circuit code.
Symptoms on Record
- Check engine light illuminated with P0446 stored
- Possible P0449 companion code
- Fuel nozzle clicking off prematurely during fill-ups
- Faint fuel odor near the rear of the vehicle
- No drivability issues—V6 runs normally
Top Causes Ranked
For the 2020 Traverse, the investigation leads here:
- Vent Valve Solenoid Failure (High Likelihood): The most common P0446 trigger across GM's crossover lineup. After five years, the solenoid can develop coil failures or valve sticking. Parts: $35–$70, labor: $80–$150.
- Connector or Wiring Corrosion (High Likelihood): Road salt and moisture corrode the vent valve solenoid's electrical connections over time. The Traverse's low ground clearance can increase road spray exposure. Repair: $75–$200.
- Charcoal Canister Contamination (Medium Likelihood): Habitual fuel overfilling saturates the canister. Family vehicles often get topped off in a hurry, making this more common than expected. Replacement: $140–$300.
- Gas Cap Seal Deterioration (Medium Likelihood): The Traverse uses a traditional threaded gas cap whose seal degrades over time. While more commonly causing P0442, it's worth checking. Replacement: $10–$25.
- PCM Software Update (Low Likelihood): GM may have released updated EVAP calibrations for the C1XX platform. A dealer reflash: $100–$180 if not under warranty.
Diagnostic Steps
Confirm the P0446 code and check for P0449. Locate the vent valve solenoid near the charcoal canister at the rear of the Traverse. Inspect the electrical connector for corrosion. Test solenoid resistance with a multimeter and apply 12V to verify actuation. A scan tool with GM enhanced mode or GDS2 access provides bidirectional testing capability for more thorough diagnosis.
Warranty Outlook
Your 2020 Traverse has exceeded GM's 3-year/36,000-mile bumper-to-bumper warranty. The federal emissions warranty of 8 years/80,000 miles covers EVAP components through 2028. If your Traverse has fewer than 80,000 miles, contact a Chevrolet dealer to have this repaired under the emissions warranty at no cost.
Summary
The P0446 on your 2020 Traverse is a common GM code that doesn't affect your family crossover's performance, safety, or three-row comfort. The vent valve solenoid is the usual resolution, and the emissions warranty may still cover the repair. Whether you visit the dealer or handle it as a DIY project, this is a manageable fix.