P2450 on 2022-2025 Ford Maverick Hybrid: EVAP Valve Causes and Fixes

What's Unique About the 2022-2025 Ford MAVERICK

The Ford Maverick, particularly the hybrid model, and its platform mates (Ford Escape Hybrid, Lincoln Corsair) are uniquely prone to this code due to specific software calibration issues acknowledged by Ford in technical service bulletins. Unlike many other vehicles where this code immediately points to a failed part, the first step for a Maverick owner should be checking for an available software update (TSB 25-2326). Additionally, Ford has specifically noted in SSM 53982 that these hybrid trucks are sensitive to overfilling the fuel tank, which can saturate the EVAP system and trigger this code.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light (Malfunction Indicator Lamp or MIL) is on
• Possible "Check Fuel Fill Inlet" message on the dash 🎬 Watch: Easy DIY fixes for the Check Fuel Fill Inlet message.board
• A faint fuel odor near the rear of the vehicle (rare)
• Difficulty starting after refueling (very rare)

Most Likely Causes

1. Powertrain Control Module (PCM) Software Error 🔴 High Probability Ford has identified a software issue in TSB 25-2326 that can falsely trigger DTC P2450 on these vehicles. This is the most common cause and should be the first item checked.
   How to confirm: A Ford dealership can check your vehicle's VIN against TSB 25-2326 to see if a software update is available. A Reddit user with a '25 Maverick Hybrid confirmed this was the fix: 'the pcm needed an update and the fault is that code. But the evap is not broken just needs to be taken in it takes like 10 minutes.'
   Typical fix: Reprogramming the PCM with the latest software version at a Ford dealership. This is covered under the emissions warranty.
   Est. part cost: $0
2. Overfilling the Fuel Tank 🔴 High Probability Ford specifically warns in SSM 53982 that overfilling the tank on hybrid models can cause this code. When you 'top off' the tank after the pump clicks off, raw fuel can be forced into the charcoal canister and EVAP lines, preventing the valve from operating correctly. TSBs instruct dealers to inform customers of this specific sensitivity.
   How to confirm: The code appears shortly after refueling. The issue may resolve on its own after driving and using some fuel.
   Typical fix: Stop refueling when the pump automatically shuts off the first time. No parts are needed if this is the cause, but repeated overfilling can permanently damage the charcoal canister.
   Est. part cost: $0
3. Faulty EVAP System Switching Valve (Vapor Blocking Valve) 🟡 Medium Probability Like any electromechanical part, this valve can fail over time by getting stuck open or closed.
   How to confirm: If a PCM update doesn't fix the issue and you are not overfilling the tank, a technician will test the valve's operation using a diagnostic scan tool (like Ford's FDRS) to command it open and closed. They will also check the wiring and connector for damage.
   Typical fix: Replacement of the EVAP switching valve, which is located near the fuel tank. A Maverick owner on MaverickTruckClub.com confirmed the dealer replaced the 'fuel vapour vent' to fix their P2450 code. Another owner on an F-150 forum had the 'fuel tank isolation valve' replaced for the same code.
   Est. part cost: $80-$150

Rare But Worth Checking

• Damaged Wiring or Connector: Rodents can chew through the wiring harness leading to the valve, or corrosion can develop at the connector, causing a loss of signal. One owner on Reddit reported this was the cause of their issue.
• Kinked or Blocked Fuel Filler Hose: On other Ford trucks, an improperly installed fuel filler neck has been found to cause a restriction, leading to EVAP system codes like P2450.
• Low 12V Battery Voltage: A user on MaverickTruckClub.com reported a P2450 code appeared concurrently with a dead 12V battery, speculating that the electrical issue may have caused the valve to report a fault.

Diagnosis Steps

1. Read the code with an OBD-II scanner to confirm P2450 is present.
2. Contact a Ford dealer with your VIN to check for open recalls or applicable TSBs, specifically TSB 25-2326.
3. If a software update is available, have the PCM reprogrammed. This is the most likely fix and is often covered by warranty.
4. If the code returns, strictly adhere to not 'topping off' the fuel tank. Stop fueling when the nozzle clicks off the first time and see if the code clears after a few drive cycles.
5. If software and refueling habits are ruled out, the next step is a physical inspection. Inspect the wiring harness and connector for the EVAP switching valve near the fuel tank for any visible damage, corrosion, or signs of rodent activity.
6. Using an advanced scan tool (like the dealer's Ford Diagnostic & Repair System - FDRS), a technician can run the 'Evaporative Emissions System Toolbox' to command the EVAP switching valve to open and close to test its functionality. If it fails to respond, it needs to be replaced.
7. If the valve tests good, the issue may be in the wiring circuit between the valve and the PCM, which will require further electrical testing with a multimeter.

Parts You'll Likely Need

• EVAP System Switching Valve / Vapor Blocking Valve / Fuel Tank Isolation Valve (OEM #NZ6Z-9F945-A (Unconfirmed, but follows Ford's numbering scheme for this type of part)) — This is the component that the P2450 code directly flags as malfunctioning. If software and user habits are not the cause, this valve is the most likely failed part. Ford's internal part number base for this component family is 9F945.
  Trusted brands: Motorcraft
  OEM price range: $100-$180
  Aftermarket price range: $80-$150

Technical Service Bulletins (TSBs) & Recalls

• TSB 25-2326: Illuminated MIL with DTC P2450 may be due to PCM software.
• SSM 53982: P2450 on Hybrid models may be due to an EVAP concern or customer overfilling the fuel tank.
• SSM 53601: Corroborates the cause on other Ford hybrid models (Escape, Corsair, Nautilus), pointing to EVAP concerns or overfilling.

Platform-Specific Known Issues

• TSB 25-2326: Notes that an illuminated MIL with DTC P2450 may be due to the PCM software level and is corrected by a reprogram. The procedure involves connecting a battery charger and using the FDRS to update the PCM and other modules.
• SSM 53982 / SSM 53601: Specifically calls out that on 2022-2025 Maverick Hybrids (and other Ford/Lincoln hybrids), P2450 can be caused by an EVAP system concern or by the customer overfilling the fuel tank. It instructs technicians to perform normal diagnostics and inform the customer about proper fueling habits.

Mechanic-Grade Diagnostic Values

• EVAP Switching / Blocking Valve Commanded Voltage — expected: ~12 Volts when commanded ON by a scan tool; ~0 Volts when commanded OFF.. Failure: If ~12V and a good ground are confirmed at the connector when commanded ON, but the valve does not produce an audible click, the valve has failed mechanically.
• Fuel Tank Pressure (FTP) Sensor Voltage (Key On, Engine Off) — expected: Approximately 2.6 - 2.65 Volts with the system vented to atmosphere (e.g., fuel cap removed).. Failure: If the voltage is stuck high or low and does not change when the tank is opened to atmosphere, the sensor or its circuit is likely faulty.

Hidden / Shadow Codes Worth Checking

• P2450:00: This is the most common sub-type for this DTC, indicating a general performance or 'stuck open' fault as detected by the PCM's self-test. It is explicitly mentioned in Ford's Special Service Messages (SSMs). (see via Standard OBD-II scanner that can read extended code information.)
• Erroneous (but in-range) FTP Sensor Data: A critical 'hidden' issue where the Fuel Tank Pressure (FTP) sensor provides incorrect readings that are still within its normal operating range. This will not set a specific code for the FTP sensor (like P0453) but will cause the PCM to incorrectly flag P2450 because it misinterprets the pressure data during the EVAP test. (see via Monitor the live data PIDs for the FTP sensor using a tool like FORScan or FDRS. Compare the reading to a known good value (e.g., near zero pressure when the fuel inlet is open).)

Scan Tool Commands That Help

• Ford IDS / FDRS / FORScan: EVAP Switching Valve (or Vapor Management Valve) On/Off Command — This is a primary diagnostic step to directly test the valve's functionality. By commanding the valve on and off, a technician can listen for the solenoid's audible click and check for voltage at the connector, confirming if the valve itself or its circuit is the point of failure.
• Ford IDS / FDRS: Evaporative Emissions System Toolbox / EVAP System Test — This is the master self-test that the PCM runs automatically. It can be initiated manually with a dealer-level tool to verify a repair has been successful and that the entire system is functioning correctly after replacing a component.

Wiring & Ground Locations

• Firewall Ground Studs — In the passenger footwell, on the firewall just under the BCM and fusebox, to the left. There are reportedly two threaded bolts available for grounding.. The PCM and related modules are grounded nearby. A poor ground in this area could cause erratic behavior in the modules that control and monitor the EVAP system.
• Rear Frame Grounds — Under the truck near the rear of the vehicle, there are several factory ground points where a bare ring terminal is fastened to the frame.. The EVAP switching valve is located near the fuel tank at the rear of the vehicle. Its circuit relies on a solid ground, and these nearby points are critical to check for corrosion or looseness.

Real Owner Repair Stories

• f150forum.com user report (2015 Ford F-150 2.7L (Similar EVAP system logic)) — Persistent P2450 code.
  ❌ Tried (didn't work) Replacing the EVAP blocking/switching valve itself did not resolve the code.
  ✅ What actually fixed it The actual cause was a bad electrical connector on the Fuel Tank Pressure (FTP) sensor. The faulty connection sent incorrect data to the PCM, causing it to misinterpret the EVAP system test and falsely trigger the P2450 code.
• f150forum.com user report (2015 F-150 with 1,200 miles) — Check Engine Light with code P2450. Auto Start-Stop feature was also inoperative.
  ✅ What actually fixed it The dealer replaced the entire fuel tank hose assembly (Part # FL3Z-9D683-F), which includes the valve. This fixed the code and restored Auto Start-Stop functionality (which is disabled by a CEL).

"I Checked Everything" — The Actual Cause

• In cases where a smoke test of the EVAP system shows no leaks, but code P2450 persists, the root cause can be electrical rather than a physical leak. A well-documented case on a similar Ford platform found that a faulty electrical connector on the Fuel Tank Pressure (FTP) sensor was sending incorrect (but still plausible) data to the PCM. The PCM misinterpreted this data during its self-test and flagged the switching valve as faulty (P2450), even though the valve itself and all hoses were perfectly fine.

OEM Part Supersession History

• N/A → N/A — While no specific supersession history was found for the Maverick's unconfirmed part number (NZ6Z-9F945-A), the base number '9F945' is consistently used by Ford for this family of EVAP valves and solenoids. It is common for these parts to be superseded with updated revisions to improve reliability.

Model Year Variations Within This Range

• 2025: TSB 25-2326 specifically calls out a potential software issue on 2025 models that can cause P2450. The fix is a PCM reprogram, making a software check the primary diagnostic step for this model year.
• 2022-2024: For these years, while a software issue is still possible, SSM 53982 places a strong emphasis on checking for physical EVAP system concerns or customer-induced faults like overfilling the fuel tank as the primary causes.