2003 Toyota Tundra P0446

How to Fix Code P0446

Introduction

Code P0446 is a common OBD-II trouble code that can affect Toyota vehicles. This code indicates that the vehicle's evaporative emission (EVAP) system has detected a leak in the vent valve circuit.

Symptoms

Some common symptoms of code P0446 include:

• Illuminated Check Engine Light
• Increased fuel consumption
• Rough idle
• Stalling

Causes

Some potential causes of code P0446 include:

• Faulty vent valve
• Damaged or disconnected vent valve circuit
• Leaks in the EVAP system
• Faulty EVAP canister

Testing the Vent Valve Circuit

To fix code P0446, you will need to test the vent valve circuit. This can be done using a multimeter. Here are the steps:

1. Disconnect the negative battery terminal.
2. Locate the vent valve. It is usually located near the fuel tank.
3. Disconnect the electrical connector from the vent valve.
4. Set the multimeter to the ohms setting.
5. Connect one lead of the multimeter to one terminal of the vent valve.
6. Connect the other lead of the multimeter to the other terminal of the vent valve.
7. The multimeter should read 0 ohms. If it reads infinity, the vent valve is faulty and needs to be replaced.

Replacing the Vent Valve

If the vent valve is faulty, it will need to be replaced. Here are the steps:

1. Disconnect the negative battery terminal.
2. Locate the vent valve. It is usually located near the fuel tank.
3. Disconnect the electrical connector from the vent valve.
4. Remove the bolts that hold the vent valve in place.
5. Install the new vent valve and tighten the bolts.
6. Reconnect the electrical connector to the vent valve.
7. Reconnect the negative battery terminal.

Conclusion

Code P0446 can be a frustrating issue, but it can be fixed by testing and replacing the vent valve circuit. By following the steps above, you can fix this code and get your Toyota back on the road.