Ford Fusion replace Evaporative Emissions (EVAP) Canister Vent Valve to fix DTC P0456

Purpose

To guide you on how to check and replace the Evaporative Emission (EVAP) Canister Vent Valve Solenoid.

Introduction

The Evaporative Emission Control (EVAP) System prevents gasoline vapors in the fuel system and fuel tank from escaping into the atmosphere where they could form unhealthful photochemical smog. Once gasoline vapors are collected in the charcoal canister, the Engine Control Module (ECM) controls the Purge Control Solenoid Valve (PCSV) to let any collected vapors from the canister back into the engine combustion chamber. The ECM controls and monitors the operation of the EVAP System. Any leak in the EVAP system makes the ECM set the Diagnostic Trouble Code (DTC) P0456.

In the 2016 Ford Fusion L4 2.0L, the ECM will set this DTC when it monitors the EVAP operation and detects any excessive fuel tank vacuum when the is engine running, but not at idling. The possible causes of this code are listed below:

• EVAP purge valve open - stuck
• EVAP system tubes blocked
• Fuel filter cap closed - stuck preventing vacuum relief (if equipped)
• Capless fuel tank filler pipe damaged preventing vacuum relief (if equipped)
• Fuel vapor elbow contaminated on the EVAP canister
• EVAP canister restricted
• EVAP canister vent valve stuck
• EVAP canister vent valve filter plugged
• Voltage Reference (VREF) circuit opened
• Fuel Tank Pressure sensor damaged

	Step Time required (hour) Sections Cautions	12 0.7 4 1

Model	Part number	Part name
2016 Ford Fusion 2.0L	CU5A9G886AA CU5Z9F945A	EVAP purge control valve  EVAP canister vent valve

Step 1 - Check the mechanical signs

During your initial inspection, check for obvious mechanical signs such as:

• A missing fuel filler cap or damage to the integrity of the cap.
• Loose or damaged vapor hoses.
• Visually inspect the EVAP canister for contamination or debris.

If there are issues, fix them first and go to the next step.

Step 2 - Check DTCs and Freeze Frame data

Using a scan tool, retrieve DTCs and Freeze Frame (FF) information and save it for later review. Freeze Frame data is a valuable part of diagnostics and gives insight into the conditions present at the time of the fault. This data helps you duplicate the conditions to find the defective area.

Step 3 - Check leak at the EVAP purge valve

Disconnect the harness connector of the EVAP purge valve and the fuel vapor hose from the purge valve to the intake manifold. Connect the hand vacuum pump to the fuel vapor hose and apply 10" vacuum. If the system cannot hold the vacuum, the EVAP purge valve has a leak and needs to be replaced.

Replace the EVAP purge valve procedure

Removal

Step 1 – Lift the vehicle and ensure the transmission is in NEUTRAL.

Step 2 – Disconnect the negative battery cable.

Step 3 – Disconnect the quick-release coupling and the EVAP purge valve connector.

Install

To install, reverse all removal steps above.

Step 4 - Check EVAP purge valve operations

Disconnect the harness connector of the EVAP canister vent valve. Disconnect the fuel vapor hose from the canister. Connect the hand vacuum pump to the canister. Because the EVAP canister vent valve solenoid is normally open, we need to connect the fuse terminal set to it. Cycle the valve several times to ensure the valve is not stuck open or closed. After that, apply the vacuum to the EVAP canister vent valve solenoid and determine whether it can hold the vacuum or not. Replace this valve if it cannot hold the vacuum.

Replace the EVAP canister vent valve solenoid procedure

Removal

Step 1 – Lift the vehicle and ensure the transmission is in NEUTRAL

Step 2 – Disconnect the negative battery cable.

Step 3 – Remove the EVAP canister.

• Disconnect the EVAP canister vent valve solenoid connector and quick connect and perform the procedure again to the couplings.
• Remove the nuts which hold the canister (35 in-lb (4Nm))

Step 4 – Remove the EVAP canister vent valve solenoid by rotating clockwise.

Install

To install, reverse all removal steps above.

Step 5 - Repair Validation

Start the engine, allow the engine to reach operating temperature and turn off accessories. 

Validate the repair by following the EVAP drive cycle requirements for the fault area. An alternative method is to drive the vehicle within the operating parameters found in the Freeze Frame data. 

Bring the vehicle to a stop and idle for 2 minutes. 

Check for pending or stored DTCs. If no DTC is found, the repair is completed.