P0456 on 2009-2014 Nissan Cube: EVAP Small Leak Causes and Fixes

What's Unique About the 2009-2014 Nissan CUBE

What makes the Nissan Cube notable for this code is that Nissan has issued multiple Technical Service Bulletins (TSBs) that directly address it. Specifically, TSB NTB17-082E and its predecessors point to a faulty o-ring on the EVAP vent control valve as a primary culprit, making diagnosis more direct. This means that instead of a wide-ranging search for a tiny leak, technicians and owners have a known, high-probability failure point to check first. 🎬 Watch: A quick DIY fix for the P0456 code on a Nissan. The vent valve is located at the rear of the vehicle, attached to the charcoal canister, which is on the passenger side near the wheel.

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 is on
• A faint fuel smell may be noticeable in rare cases
• No impact on vehicle performance or drivability
• A "loose gas cap" warning may appear on the dash, even if the cap is tight.

Most Likely Causes

1. Loose or Faulty Fuel Cap 🔴 High Probability This is the most common cause for any vehicle, as the cap seal can wear out or simply not be tightened correctly after refueling. It's always the first thing to check.
   How to confirm: Ensure the gas cap is tightened until it clicks at least once. Inspect the cap's rubber seal for cracks, stiffness, or debris. If the seal is damaged, the cap needs replacement. Some owners suggest trying to get an OEM cap, as aftermarket ones can sometimes fail to seal correctly.
   Typical fix: Tighten or replace the fuel cap.
   Est. part cost: $10-$35
2. EVAP Vent Control Valve O-Ring / Assembly 🔴 High Probability Nissan TSB NTB17-082E specifically identifies a leak at the vent control valve o-ring as a common cause for P0456 on the Cube and many other Nissan models. The rubber o-ring can become brittle and crack over time. The valve is exposed to the elements at the rear of the vehicle.
   How to confirm: A smoke test is the definitive method. Smoke is introduced into the EVAP system, and if it escapes from the area where the vent control valve mounts to the charcoal canister, this is the cause. Visually, the mounting surfaces must be clean and free of cracks.
   Typical fix: Previously, the TSB advised replacing only the o-ring. However, the latest revision (NTB17-082E) from Feb 2022 states the o-ring is no longer available as a separate service part and instructs technicians to replace the entire vent control valve assembly. 🎬 Watch: How to replace the vent solenoid on a Nissan. The older TSBs explicitly state not to add any lubrication to the o-ring upon installation.
   Est. part cost: $50-$90
3. Failed EVAP Vent Control Valve 🟡 Medium Probability The vent control valve (also called a vent solenoid) is located near the charcoal canister at the rear of the vehicle. It can get stuck open or closed, causing a leak or preventing the system from sealing for its self-test. This is a notorious failure point on many Nissan vehicles.
   How to confirm: A scan tool can command the valve to open and close to test its function. You may also hear a click when it's activated. If it doesn't operate or is stuck, it needs replacement. You can also test it with a multimeter for resistance or by applying 12v power to see if it actuates.
   Typical fix: Replace the EVAP vent control valve.
   Est. part cost: $50-$90
4. Failed EVAP Canister Purge Valve ⚪ Low Probability This valve is typically located in the engine bay on the right side of the engine on top, and controls the flow of stored vapors to the engine. 🎬 See this short walkthrough on locating the canister purge valve. It can fail by sticking slightly open, creating a small leak.
   How to confirm: With the engine off, disconnect the valve and try to blow through it. If air passes through, it's stuck open and faulty. You can also check for vacuum at the port while the engine is running; there should be none if it's working correctly.
   Typical fix: Replace the purge valve.
   Est. part cost: $40-$100
5. Cracked or Disconnected EVAP Hoses ⚪ Low Probability Rubber hoses can become brittle and develop small, hard-to-see cracks over time, especially at connection points or on top of the fuel tank where they are exposed to stress.
   How to confirm: Visually inspect all accessible EVAP lines between the engine bay, fuel tank, and charcoal canister. A smoke test is the most effective way to find a small hose leak.
   Typical fix: Replace the cracked section of hose.
   Est. part cost: $5-$20

Rare But Worth Checking

• Cracked Charcoal Canister: The plastic housing of the canister itself can develop hairline cracks, leading to a leak. This is less common than valve or hose failures but should be checked during a smoke test. Shaking the canister should not produce rattling sounds, which would indicate broken internal charcoal.
• Faulty Fuel Tank Pressure (FTP) Sensor: In rare cases, the sensor that measures system pressure can malfunction, sending incorrect data to the computer and falsely triggering a leak code. This often sets other codes like P0451.
• Cracked Fuel Sending Unit / Fuel Pump Module: On some Nissan models like the Sentra, the plastic top of the fuel sending unit under the rear seat has been known to develop cracks, causing a P0456 code. This can be inspected by lifting the rear seat cushion and removing the access cover.

Diagnosis Steps

1. Read the code with an OBD-II scanner to confirm P0456 is the only code present.
2. Inspect the fuel cap. Remove it, check the seal for damage, and reinstall it, ensuring it clicks several times. Clear the code.
3. Drive for a few days to see if the code returns. The EVAP monitor test often runs after the vehicle has been parked for several hours.
4. If the code returns, locate the EVAP vent control valve. On the Cube, it is attached to the charcoal canister, located at the rear of the vehicle on the passenger side, near the wheel. You may not need to jack up the car to access it.
5. Visually inspect the vent control valve and its mounting point on the canister for obvious cracks or damage, as highlighted in TSB NTB17-082E.
6. Inspect all visible EVAP hoses and lines for cracks, disconnections, or brittleness.
7. If the leak is not visually apparent, the most effective method is to perform a smoke test. This involves injecting pressurized smoke into the EVAP system's service port and watching for where it escapes. Pay close attention to the vent valve/canister area.
8. Based on the smoke test results, replace the leaking component. Given the TSB, the vent control valve assembly is the most likely culprit after the gas cap.

Parts You'll Likely Need

• Fuel Filler Cap (OEM #17251-79960) — This is the most frequent cause of P0456. The seal wears out over time, preventing the system from holding pressure.
  Trusted brands: Nissan (OEM), Gates, Stant
  OEM price range: $25-$40
  Aftermarket price range: $10-$20
• EVAP Vent Control Valve O-Ring (OEM #14935-JF02B) — Specifically identified in Nissan TSBs as a common failure point causing P0456. The rubber degrades and leaks. NOTE: As of TSB NTB17-082E (Feb 2022), Nissan no longer services this o-ring alone and recommends replacing the entire valve assembly.
  Trusted brands: Nissan (OEM)
  OEM price range: $5-$15
  Aftermarket price range: $3-$10
• EVAP Vent Control Valve (OEM #14935-JF00A) — If the valve itself is stuck, electronically failed, or its integrated o-ring is leaking, it will cause this code. This is the most common fix after the gas cap. This part is also known as a vent solenoid. The part has been superseded multiple times; a current replacement number is 14935-JF02C.
  Trusted brands: Nissan (OEM), Bosch, Dorman
  OEM price range: $60-$90
  Aftermarket price range: $40-$70

Related Codes That Often Appear With This One

• P0442 — This indicates a medium-sized EVAP leak. If a small leak (P0456) worsens, it can trigger a P0442.
• P0455 — This indicates a large EVAP leak. It's less common to see with P0456 unless there are multiple leak sources or a component fails catastrophically.

Technical Service Bulletins (TSBs) & Recalls

• NTB17-082E: DTC P0456 CAUSED BY EVAP LEAK AT VENT CONTROL VALVE O-RING
• NTB17-082b: NISSAN; DTC P0456 CAUSED BY EVAP LEAK AT VENT CONTROL VALVE O-RING
• NTB13-097J: EVAP LEAK DTC P0442, P0455, P0456 INFORMATION
• NTB09020F: SERVICE INFORMATION If one or more of these EVAP leak DTCs are stored (P0442, P0455, P0456) on a 2007 through 2011 Nissan vehicle, a loose fuel fill cap may be the cause.

Platform-Specific Known Issues

• TSB NTB17-082E: The latest version of this TSB (Feb 2022) confirms the cause is a leak at the vent control valve o-ring but changes the repair procedure. It now states the o-ring is no longer a separate service part and instructs to 'Replace the vent control valve as an assembly'.
• TSB NTB09020F: Notes that a loose fuel fill cap may be the cause for P0456 and other EVAP codes on Nissan vehicles.
• TSB NTB13-097J: Provides general diagnostic information for P0442, P0455, and P0456.

Mechanic-Grade Diagnostic Values

• EVAP Canister Purge Valve Resistance — expected: 30 to 38 ohms (when engine is cool). Failure: A reading outside this range, or an open/infinite reading, indicates a faulty valve coil.
• EVAP Canister Vent Solenoid/Valve Resistance — expected: Generally between 20 and 50 ohms. One source cites 28.3 ohms as a good reading on a sample part.. Failure: No reading (open circuit) or a reading significantly outside the typical range suggests the solenoid coil is bad.

Hidden / Shadow Codes Worth Checking

• Permanent DTC (pDTC): After a repair, even if the Check Engine Light is off, a permanent DTC like P0456 may remain stored. This code cannot be cleared with a standard scanner command. It will only be cleared by the ECU after it successfully runs and passes the internal EVAP monitor test, which can take several drive cycles. (see via Advanced scan tools like Nissan's CONSULT can display the status of permanent DTCs and the readiness of the EVAP monitor.)

Scan Tool Commands That Help

• Nissan CONSULT-III plus: EVAP System Leak Check (Active Test) — This function is used to verify a repair. The scan tool commands the vent control valve to close, sealing the system. The technician can then monitor system pressure to confirm the leak is fixed without waiting for the automatic monitor to run.
• Nissan CONSULT-III plus: SRT (System Readiness Test) & pDTC Display — Used to check the status of the EVAP monitor ('complete' or 'incomplete') and to see if a Permanent DTC for P0456 is still stored after a repair. This confirms if the vehicle's own self-test has passed.
• Advanced Bidirectional Scanners: EVAP Vent Solenoid ON/OFF Command — This command allows a technician to manually close the normally-open vent valve. This is essential before performing a smoke test to ensure the system is sealed for the test. You should hear the valve click when commanded.

Wiring & Ground Locations

• Main Engine Ground — A primary ground goes from the intake manifold to the battery. Another goes from the exhaust side of the cylinder head to the firewall.. A poor engine ground can cause a variety of electrical issues and incorrect sensor readings, though it's not a primary cause for a specific leak code like P0456, it's fundamental for overall system health.
• Interior Ground Points — Common interior ground points are often found behind the kick panels on the driver's or passenger's side, typically a bolt to the bare metal chassis.. While not directly tied to the EVAP solenoids at the rear of the car, these grounds are important for the proper function of the BCM and other interior modules that may relay information or warnings.
• EVAP Vent Control Valve Connector — At the EVAP vent control valve, attached to the charcoal canister at the rear of the vehicle.. This is the direct electrical connection for the most likely failing component. One wire should have 12V with the key on, and the other is a ground controlled by the ECU. Testing for power here is a key diagnostic step.

OEM Part Supersession History

• 14935-JF00A → 14935-JF00B, 14935-JF00C, 14935-JF00D, 14935-JF00E, 14935-JF01B, 14935-JF01C, and finally 14935-JF02C — Revisions by the manufacturer to improve reliability or change suppliers. The high number of supersessions points to a known issue with the original design.
  Heads up: The latest part number, 14935-JF02C, is the recommended replacement for all previous versions for the Nissan Cube and other models.
• 14930-ET000 → 14930-EN20A — Revision for the EVAP Canister Purge Valve (located in the engine bay).