P0446 Emissions Code

[Transplant]

There's a couple threads on here about the P0446 code but I'm slightly confused. I'm throwing this code, I have looked at my charcoal canister, and confirmed that my purge valve on the canister is working properly (applied 12 volts to the valve) and there's no visible damage to the wiring. I'm unable to confirm a signal to the purge valve connector, it appears I might need Forscan for that? I also see someone mentioned a vent solenoid fixed their P0446 code, can anyone clarify what the vent solenoid is? I'm just looking for some guidance for where to look next. Thanks all.

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[CajunMick]

Word out there is if at the pump one continues the fillup past the first pump nozzle shutoff “click”, trying to fill until, it spills, that raw gas could be sucked into that carbon canister and could throw alarm.

Have a neb who ask to read code. Fault at canister. I ask if he or wife overfilling past first click. Yep. Advised him don’t do that. Ever. Haven’t heard from him again.

 

[BlueSpec1]

One of the 2.0L EVAP Valves is at front of the engine

Evaporative Emission (EVAP) Purge Valve
• The EVAP purge valve (located near the engine) is part of the enhanced EVAP system controlled by the PCM.
This valve controls the flow of vapors (purging) from the EVAP canister to the intake manifold during various engine operating modes.
The EVAP purge valve is a normally closed valve. The PCM outputs a duty cycle between 0% and 100% to control the EVAP purge valve.
• The EVAP purge valve controls the flow of vacuum from the engine and creates a target vacuum on the fuel tank.

Remove the air cleaner outlet pipe.
• NOTE: Use care when moving the secondary EVAP line, to prevent contact with the liquid fuel supply line.
Disconnect the quick release couplings and remove the secondary EVAP line.

All vehicles
• Detach the hose clip.
• Disconnect the electrical connector.
• NOTE: Use care when moving the secondary EVAP line, to prevent contact with the liquid fuel supply line.
Disconnect the quick release couplings and remove the secondary EVAP line.

From a 2.0L engine looks like the valve and several hose assemblies connected to the valve.

Maverick 2.0L EcoBoost A/T FWD XLT Crew Cab Pickup Fleetside 2023 NZ6Z9D289A.
Tube Assy - Fuel Vapour Separator.
Part Number: NZ6Z-9D289-A
Supersession(s): NZ61-9D289-AA; NZ619D289AA; NZ6Z9D289A

2.0L Additional EVAP Valves:

Evaporative Emission (EVAP) Vapor Blocking Valve
The EVAP vapor blocking valve (VBV) is a normally open valve, electrically closed by the PCM, to isolate the fuel tank from the rest of the EVAP system.
The EVAP vapor blocking valve (VBV) will automatically open to relieve excess pressure or vacuum, in the fuel tank, if the pressure or vacuum reaches a maximum calibrated value.

• Evaporative Emission (EVAP) Canister Vent Valve
The EVAP canister vent valve (located in the EVAP canister dust box) is part of the enhanced EVAP system controlled by the PCM.
During the EVAP leak check monitor, the EVAP canister vent valve seals the EVAP canister from the atmospheric pressure.
This allows the EVAP purge valve to achieve the target vacuum in the fuel tank during the EVAP leak check monitor.
• The EVAP canister vent valve seals the EVAP system from the atmosphere.
It is closed by the PCM (100% duty cycle) to allow the EVAP purge valve to achieve the target vacuum on the fuel tank

Evaporative Emission Canister Vent Solenoid
Disconnect the EVAP canister vent solenoid electrical connector.

Rotate the EVAP canister vent solenoid clockwise.
Remove the EVAP canister vent solenoid.

Evaporative Emission (EVAP) Check Valve
The EVAP check valve is used on turbocharged engines to prevent boost pressure from forcing open the EVAP purge valve and entering the EVAP system.
The valve is open under normal engine vacuum.
The valve closes during boost conditions to prevent the fuel tank from being pressurized and hydrocarbons forced out of the EVAP system into the atmosphere through the EVAP canister vent valve.
When the engine is OFF, or at atmospheric pressure, the EVAP check valve is in an indeterminate state.
The EVAP check valve is an integral part of the EVAP purge valve assembly.


Fuel tank mounted or inline fuel vapor control valve, fuel vapor vent valve, EVAP canister, fuel tank mounted or fuel pump mounted or inline Fuel Tank Pressure Sensor (FTPS), EVAP purge valve, EVAP check valve (if equipped), intake manifold hose assembly, EVAP canister vent valve, PCM and connecting wires, and fuel vapor hoses.


A valve inside the fuel tank mounted fuel vapor tube assembly prevents liquid fuel from entering the EVAP canister and the EVAP purge valve under any vehicle altitude, handling, or rollover
condition.


The normally open VBV is a PCM controlled valve that blocks the flow of vapors from the fuel tank to the EVAP canister during engine operation.
Closing the VBV during engine operation allows the EVAP system to purge the EVAP canister without purging the fuel tank.
The VBV will open to relieve excess fuel tank pressure if the fuel tank pressure reaches a maximum calibrated value

 

[Transplant]

That is super helpful, exactly what I was looking for. I really appreciate the help BlueSpec1.

 

[Mkuket]

They published a TSB earlier this month, two of the vapor lines underneath the truck by the gas tank running to the engine are touching and can rub a hole through one of the lines. Definitely check there

 

[CajunMick]

If you able, Can you advise the year midels affected, or the TSB #?

 

[Mkuket]

TSB # 25-2308 - Looks like all 2022-2024 gas and hybrid Mav’s and if that’s the cause, should hopefully be covered under any warranty you still have

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