P0446 - EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT

The Evaporative Emission Control System (EVAP) vent valve is used for sealing the vent. Thus, the evaporative emission control system (EVAP) pressurizes and ensures that there cannot be leaks. This valve has a 12-volt battery voltage supply with the key on.

The ground is provided by the Engine Control Module (ECM) controller and when grounded it is activated, i.e. closed. In case the Engine Control Module (ECM) detects a short to ground or a short to battery voltage in the control circuit, the DTC code P0446 OBD2 is displayed. This code also means that the ECM has detected that the EVAP system has failed to maintain a vacuum for a certain period.

• Check Engine light is on.
• You can smell a combustible odor caused by the release of fuel vapors.

When the fault code P0446 OBD II is set, it means that one or more of the following problems have occurred:

• The fuel cap may be connected incorrectly or an element may be present.
• The resistance of the control circuit of the ventilation valve may be short or too high.
• The ventilation valve may be blocked.
• The ventilation valve may be defective.
• A faulty ventilation valve.

When faced with the diagnostic code P0046, you can do the following to repair it:

• Check the electrical system of the ventilation valve. Make sure the wires are in good condition. They can not rub or cause a short in the circuit. Repair any problems in the circuit and replace defective components if necessary.
• Check the resistance in the control circuit. If there are problems with it, make the necessary repairs.