P0446 on 2007-2008 Saturn Aura: EVAP Vent System Causes and Fixes

What's Unique About the 2007-2008 Saturn Aura

For this specific vehicle and its platform mates (Chevy Malibu, Pontiac G6), General Motors issued a Technical Service Bulletin (TSB 07-06-04-023A) acknowledging a common problem. The issue is frequently caused by spider nests or other debris clogging the fresh air inlet tube of the EVAP canister vent valve solenoid. This makes the problem less about a defective part from the factory and more about a design vulnerability to outside elements, leading to a very specific and common symptom: difficulty filling the fuel tank.

Symptoms You May Notice

• Check Engine Light is illuminated
• Difficulty filling the fuel tank (gas pump nozzle clicks off frequently before the tank is full)
• A faint fuel smell (less common)
• Inability to use remote start feature (if equipped), as it is often disabled when a Check Engine Light is active.

Most Likely Causes

1. Blocked or Faulty EVAP Vent Valve Solenoid 🔴 High Probability → Shop Vapor Canister A GM Technical Service Bulletin (TSB 07-06-04-023A) specifically identifies that the fresh air inlet for the solenoid is prone to being blocked by spider nests or other debris. This is a well-documented issue on owner forums and technician databases for the Aura and its platform mates.
   How to confirm: Locate the EVAP canister vent solenoid near the fuel tank, typically on the canister itself. Remove it and inspect the air inlet tube and the solenoid itself for debris, webs, or dirt. You can also test the solenoid's operation by applying 12V power and ground to its terminals to see if it clicks open and closed. A failed solenoid may not actuate at all, or may be mechanically stuck.
   Typical fix: The TSB recommends cleaning the solenoid and its air chamber thoroughly. After cleaning, install a small piece of fiberglass screen material over the air inlet and secure it with a zip tie to prevent future blockages. If the solenoid is electrically faulty or mechanically stuck, it must be replaced. Common replacements are ACDelco 214-2149 or Dorman 911-030.
   Est. part cost: $30-$70
2. Damaged Wiring or Connector for Vent Solenoid 🟡 Medium Probability The component is located under the vehicle, exposing its wiring to moisture, road salt, and physical damage over time, leading to corrosion and poor connections.
   How to confirm: Visually inspect the wiring harness and connector leading to the vent solenoid for any signs of corrosion (green or white powder), chafing, or broken wires. Use a multimeter to check for 12V power at the connector with the key on and check for continuity to ground on the control wire when commanded by a scan tool.
   Typical fix: If the connector is corroded, it may need to be cleaned or replaced with a new pigtail connector. Damaged sections of wire should be repaired or replaced.
   Est. part cost: $15-$30 for a pigtail connector
3. Clogged EVAP Charcoal Canister or Vent Hoses ⚪ Low Probability → Shop Vapor Canister
   How to confirm: Disconnect the hoses leading to and from the charcoal canister. Inspect them for blockages or cracks. If you find black charcoal pellets in the lines, the canister has failed internally and must be replaced.
   Typical fix: Replace the charcoal canister and clean out all associated EVAP lines to remove any loose charcoal pellets.
   Est. part cost: $100-$250

Rare But Worth Checking

• Faulty Fuel Tank Pressure Sensor: → Shop Fuel Tank While less common for this specific code, a faulty pressure sensor can provide incorrect data to the ECM, leading it to misinterpret the EVAP system's state. One owner reported this as the ultimate fix after replacing other components.

Diagnosis Steps

1. Confirm the presence of code P0446 🎬 See this breakdown of common P0446 causes and fixes. with an OBD-II scanner.
2. Attempt to fill the fuel tank. If the pump clicks off repeatedly, it strongly suggests a vent path restriction, corroborating the P0446 code.
3. Raise and safely support the vehicle.
4. Locate the EVAP canister and vent solenoid assembly. It is typically mounted on the subframe near the fuel tank, often behind the driver's side rear wheel.
5. Visually inspect the vent solenoid connector and wiring for corrosion, damage, or loose connections.
6. Disconnect the vent solenoid. Inspect the solenoid's air inlet port for spider webs, dirt, or other debris as noted in TSB 07-06-04-023A.
7. If debris is found, clean the solenoid and its air chamber thoroughly. Consider adding a screen to the inlet to prevent recurrence.
8. If no blockage is visible, test the solenoid. Apply a 12V power source and ground to the solenoid's pins; you should hear a distinct click as it actuates. If it doesn't click, or is stuck, the solenoid has failed.
9. If the solenoid works, check the vent hoses connected to the canister for blockages or kinks.
10. If the solenoid and hoses are clear, use a multimeter to check for 12V at the solenoid connector with the key in the 'On' position.
11. If all components and wiring test good, the issue could be a clogged charcoal canister or, rarely, a faulty ECM.

Parts You'll Likely Need

• EVAP Canister Vent Valve Solenoid (OEM #GM 13575701 (replaces 10382104, 25932570)) — This is the most common failure point for P0446 on this vehicle, often due to blockage from debris as identified in a GM TSB.
  Trusted brands: ACDelco (214-2149), Dorman (911-030), Standard Motor Products
  OEM price range: $40-$60
  Aftermarket price range: $30-$50
• EVAP Vent Solenoid Connector Pigtail — The under-vehicle location makes the connector susceptible to corrosion, which can cause an electrical fault and trigger P0446.
  Trusted brands: ACDelco, Dorman
  OEM price range: $20-$35
  Aftermarket price range: $15-$25

Technical Service Bulletins (TSBs) & Recalls

• 07-06-04-023A: Addresses difficulty filling the fuel tank and DTC P0446, pointing to a blocked EVAP canister vent valve solenoid and providing a procedure to clean it and install a protective screen.

Platform-Specific Known Issues

• Per TSB 07-06-04-023A, the design of the vent solenoid's fresh air inlet makes it highly susceptible to being clogged by spider webs and other debris, which is a primary cause for P0446 on this model and its platform mates.

Mechanic-Grade Diagnostic Values

• EVAP Canister Vent Valve Solenoid Resistance — expected: 20-40 Ohms. Failure: A reading of infinite resistance (open circuit) or near-zero resistance (short circuit).
• EVAP Vent Solenoid Connector Voltage (Key On) — expected: Approximately 12V at Pin A (Red/White wire). Failure: No voltage indicates a problem with the power supply, likely the 'EMISSION 2' fuse or wiring.

Scan Tool Commands That Help

• Tech2 / GDS2 (or equivalent professional scanner): EVAP Canister Vent Solenoid Valve ON/OFF Command — This bidirectional control is used to directly test the functionality of the vent solenoid. While commanding the valve ON and OFF, a technician should listen for an audible 'click' from the solenoid, confirming it is receiving the command and is mechanically actuating. This can quickly determine if the solenoid is electrically dead or stuck.

Wiring & Ground Locations

• EVAP Vent Solenoid Connector — At the vent solenoid, mounted near the charcoal canister by the fuel tank.. This is the primary test point. Pin A (Red/White wire) should have 12V+ power from the EMISSION 2 fuse with the key on. Pin B (White wire) is the control circuit that the ECM grounds to close the valve. Testing here confirms if power is reaching the solenoid and if the control circuit is intact.
• G401 / G403 — In the rear luggage compartment, below the taillight assembly.. These are main chassis grounds in the rear of the vehicle. While the vent solenoid is controlled directly by the ECM, a poor chassis ground for the entire control module system can cause erratic electrical behavior and phantom codes. Checking these grounds is a good step if direct circuit testing is inconclusive.

Real Owner Repair Stories

• 2CarPros Forum User 'CUBPILOT' (2007 Saturn Aura, 3.5L) — Initially had code P0455, replaced gas cap, then got code P0449 (EVAP Vent Solenoid Circuit Malfunction).
  ❌ Tried (didn't work) Replacing the gas cap (which changed the code from P0455 to P0449)., Initially looking for the part on the engine (confusing it with the purge valve).
  ✅ What actually fixed it The user correctly identified the vent valve's location at the rear of the gas tank but concluded the repair was too difficult for a DIY job on the ground. The repair manual indicated the exhaust and fuel tank needed to be lowered for access, highlighting the significant labor involved in what seems like a simple part swap.
• NHTSA ODI #10263762 — An owner reported that the fuel nozzle shut off intermittently or prematurely while filling the vehicle and the SES lamp set DTC P0446. A dealer estimate for the repair reached $1,000.
• NHTSA ODI #10303292 — In a related Saturn model, an owner reported that the gas tank hissed loudly when undoing the gas cap and made a loud popping sound like pressure releasing from a plastic bottle when the P0446 code was present.

"I Checked Everything" — The Actual Cause

• A known failure pattern on GM vehicles involves a blockage that a smoke test may not easily find. One owner reported that after multiple failed attempts to fix a P0446, the final solution was to disconnect all EVAP lines running to the canister and vent valve and thoroughly blow them out with compressed air. This suggests a small, stubborn obstruction like a spider web or debris can get lodged in a corner or tube, restricting flow enough to set the code but not presenting as a typical 'leak'.

OEM Part Supersession History

• 10382104 → 25932570, then 13575701 — Standard part evolution and design updates by GM.
  Heads up: The parts are direct replacements and should be fully compatible. A forum user in 2011 was sold part number 25932570 for this repair, confirming its place in the supersession chain.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Premature Timing Chain Stretch (3.6L V6 LY7) 🔴 High — Very common on the Aura XR model with the 3.6L V6, often occurring between 60,000 and 100,000 miles. Triggers codes like P0008, P0009, P0017, P0018. (Ref: GM issued Special Coverage Adjustment #11340C for other models with this engine, but the Aura was not consistently included and the program is now expired.)
• 6-Speed Automatic Transmission Failure (6T70) 🔴 High — The 3-5-R wave plate is a known weak point in the 6T70 transmission paired with the 3.6L V6, leading to failure, harsh shifts, or loss of reverse gear.
• Intermediate Steering Shaft Clunk/Noise 🟠 Medium — A common issue where a clunking or rattling noise is heard and felt in the steering wheel at low speeds over bumps or when turning. (Ref: TSB #06-02-32-007G addresses this issue by lubricating or replacing the intermediate shaft with a revised design.)
• 4-Speed Automatic Transmission Problems (4T45-E) 🟠 Medium — Common on models with the 3.5L V6. Issues include failed shift solenoids, TCC solenoid failure, and slipping or harsh shifts.
• Blown High-Speed Cooling Fan Fuse 🟡 Low — The 30-amp fuse for the cooling fans is known to blow, which can cause the engine to run hot or overheat in traffic.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used EVAP vent solenoid from a junkyard is a reasonable choice if it can be tested before purchase (apply 12V and listen for a click) and the connector pins are free of corrosion. Given the low cost of new aftermarket parts, the savings may be minimal, but it is a viable option. A used charcoal canister is also acceptable if the donor vehicle has no EVAP codes and there are no loose charcoal pellets in the lines.

Donor-vehicle mileage cap: roughly under 100000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For the vent solenoid, check for heavy rust or corrosion on the electrical connector pins.
• Inspect the vent port for obvious blockages like mud or insect nests.
• If buying a charcoal canister, shake it gently; there should be no rattling sound, which would indicate broken internal media.
• Prioritize parts from vehicles in dry, salt-free climates if possible, as corrosion is a primary failure mode.

OEM-only on this vehicle (don't cheap out):

• No parts for this specific P0446 repair are considered 'OEM-only'. Aftermarket solutions are widely available and generally considered reliable.

Aftermarket brands forum-validated for this vehicle:

• ACDelco (OEM supplier)
• Dorman
• Standard Motor Products (SMP)

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0008 — A common engine performance code on the Aura XR 3.6L V6 related to timing chain stretch, which is a known high-severity issue for this model.
• P0009 — Related to timing chain alignment issues on the 3.6L V6 engine, often appearing alongside other timing-related codes.
• P0017 — Crankshaft/Camshaft alignment code frequently triggered by the premature timing chain stretch common in 2007-2008 Aura XR models.
• P0018 — Another timing-related code associated with the 3.6L V6 LY7 engine's known timing chain failure mode.

Frequently Asked Questions