P0456 on 2017-2024 Nissan Murano: Causes and Fixes for a Small EVAP Leak

What's Unique About the 2017-2024 Nissan MURANO

For this generation of Nissan Murano and its platform mates, the P0456 code is very frequently linked to a specific, well-documented failure point. Nissan has issued multiple Technical Service Bulletins (TSBs), with the most current being NTB17-082E, identifying that the O-ring for the EVAP canister vent control valve is prone to drying out and cracking, causing this exact small leak code. While earlier bulletins advised replacing just the O-ring, the latest guidance recommends replacing the entire vent control valve assembly. This known issue makes the vent valve area the primary suspect on the Murano and other Nissan/Infiniti models of this era, even before considering other common causes like a loose gas cap.

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 smell of fuel, particularly around the rear of the vehicle or after being parked
• Slight decrease in fuel economy over a long period
• Difficulty filling the gas tank (fuel pump nozzle clicks off repeatedly), which can indicate a stuck vent valve

Most Likely Causes

1. EVAP Vent Control Valve O-Ring Failure / Faulty Valve 🔴 High Probability → Shop Vapor Canister Nissan has issued multiple TSBs (e.g., NTB17-082a, NTB17-082b, NTB17-082E) specifically for this failure across most of its lineup, including the Murano. The rubber O-ring that seals the valve to the charcoal canister can dry out, crack, and create a small leak. The valve itself can also fail internally, getting stuck and failing to seal.
   How to confirm: A smoke test is the definitive method. A technician will introduce smoke into the EVAP system and look for it escaping from the vent control valve where it mounts to the canister, located at the rear of the vehicle near the passenger side wheel. 🎬 Watch: A professional diagnosis of the P0456 code on a Murano. A scan tool can also command the valve to close; if the system cannot hold a vacuum after the valve is commanded shut, the valve or its seal is faulty.
   Typical fix: Replace the entire EVAP vent control valve assembly. While older TSBs advised replacing only the O-ring, the most recent bulletin (NTB17-082E) states the O-ring is no longer available as a separate service part and instructs technicians to replace the valve as a complete assembly. This is a common DIY repair that many owners report completing in under 30 minutes. 🎬 Watch: How to replace the vent and purge control valves.
   Est. part cost: $60-$90 for the complete valve assembly.
2. Loose or Faulty Gas Cap 🟡 Medium Probability → Shop Fuel Tank Cap This is a universal cause for P0456 on all vehicles. The gas cap is a critical sealing point. If not tightened until it clicks, or if its rubber seal is old, cracked, or dirty, it will cause a leak.
   How to confirm: First, ensure the cap is tightened properly. If the light returns, inspect the rubber seal on the cap for cracks, stiffness, or debris. Replacing the cap with a new OEM part is a cheap and easy diagnostic step before moving to more complex procedures. 🎬 See this complete guide for fixing Nissan EVAP errors.
   Typical fix: Replace the gas cap with a new OEM or high-quality aftermarket part.
   Est. part cost: $20-$40
3. Faulty EVAP Canister Purge Valve ⚪ Low Probability → Shop Vapor Canister This valve, located in the engine bay, can get stuck open, creating a constant small vacuum leak. While less common than the rear vent valve failure on this platform, it is still a possible cause.
   How to confirm: With the vehicle off, the valve should be closed. It can be removed and tested by trying to blow through it; if air passes, it's stuck open and faulty. A mechanic can also command it with a scan tool to check its operation.
   Typical fix: Replace the purge valve.
   Est. part cost: $40-$80
4. Cracked or Disconnected EVAP Hoses ⚪ Low Probability Rubber hoses can become brittle and crack over time due to age and heat cycles. This is less common than the valve O-ring but still possible, especially at connection points.
   How to confirm: A visual inspection may reveal obvious cracks, but a smoke test is the most effective way to find a small hose leak.
   Typical fix: Replace the damaged section of hose.
   Est. part cost: $10-$30

Rare But Worth Checking

• Cracked EVAP Charcoal Canister: → Shop Vapor Canister The canister itself can develop hairline cracks from road debris or age, creating a leak. This is usually found during a smoke test when other, more common components have been ruled out.
• Leaking Fuel Filler Neck: → Shop Fuel Filler Neck Corrosion or damage to the metal pipe leading to the fuel tank can cause a leak. This is more common in regions with heavy road salt use and would typically be found with a smoke test.

Diagnosis Steps

1. Check the Gas Cap: Ensure it is tight and clicks when closed. Remove it and inspect the seal for any cracks or damage. If in doubt, replace it, clear the code, and drive for a few days to see if the light returns.
2. Visual Inspection: Look over the EVAP hoses in the engine bay and around the charcoal canister for any obvious cracks, disconnections, or damage. The canister and vent valve are located at the rear of the vehicle, typically on the passenger side behind the rear wheel.
3. Perform a Smoke Test: This is the most effective way to find the leak. A mechanic will connect a smoke machine to the EVAP service port. The machine fills the system with low-pressure smoke, which will become visible at the leak point.
4. Inspect the Vent Control Valve: During the smoke test, pay close attention to the area where the vent control valve mounts to the charcoal canister. Per Nissan TSBs, this is the most likely leak source on a Murano.
5. Inspect Hoses and Canister: If no leak is found at the vent valve, trace the smoke through all EVAP lines, the purge valve, and the canister itself to find the source of the leak.
6. Test Valves Electronically: A bidirectional scan tool can be used to command the purge and vent valves to open and close, verifying their electronic function and ability to seal the system.

Parts You'll Likely Need

• EVAP Vent Control Valve (OEM #14935-JF00E) — This valve's O-ring is the most common failure point according to Nissan TSBs. The latest TSB (NTB17-082E) recommends replacing the whole assembly. This part number is superseded by several newer versions, such as 14935-JF02C.
  Trusted brands: Nissan (OEM), Bosch, Hitachi, Dorman
  OEM price range: $70-$90
  Aftermarket price range: $45-$70
• EVAP Vent Control Valve O-Ring (OEM #14935-JF02B) — Specifically cited in older TSBs (like NTB17-082b) as the direct fix for P0456. However, the latest TSB revision (NTB17-082E) notes this part is no longer available separately from Nissan and advises replacing the entire valve assembly.
  Trusted brands: Nissan (OEM)
  OEM price range: $5-$15
  Aftermarket price range: $5-$10
• Fuel Filler Cap (Gas Cap) (OEM #17251-3JA0A) — A worn or loose gas cap is a very common cause of a P0456 code and the easiest part to replace as a first step.
  Trusted brands: Nissan (OEM), Stant
  OEM price range: $25-$40
  Aftermarket price range: $15-$25

Related Codes That Often Appear With This One

• P0442 — This indicates a medium-sized EVAP leak. If the small leak from P0456 worsens (e.g., the O-ring crack grows), it can eventually trigger a P0442.
• P0455 — This indicates a large EVAP leak. It's often seen if the gas cap is left off entirely or a major hose becomes disconnected. It can appear alongside P0456 if the system has multiple leak points of different sizes.

Technical Service Bulletins (TSBs) & Recalls

• NTB17-082E: DTC P0456 CAUSED BY EVAP LEAK AT VENT CONTROL VALVE O-RING
• NTB13-097J: EVAP LEAK DTC P0442, P0455, P0456 INFORMATION
• NTB17-082b: NISSAN; DTC P0456 CAUSED BY EVAP LEAK AT VENT CONTROL VALVE O-RING
• NTB17-082a: NISSAN; DTC P0456 CAUSED BY EVAP LEAK AT VENT CONTROL VALVE O-RING
• ITB17-042c: INF

Platform-Specific Known Issues

• Nissan Technical Service Bulletin NTB17-082E, the latest revision, applies to all 2008 and newer Nissan vehicles (including the Murano) and states that if P0456 is present and the leak is traced to the vent control valve O-ring, the entire valve assembly should be replaced.
• An owner on NICOclub forums with a Nissan Rogue (which shares the issue) documented the repair, noting: 'After searching the forums I learned that when this code is triggered on the Rogue, it is more often than not the Vent Control Valve... I first replaced the gas cap... the light came back on.' He then replaced the valve and fixed the issue.
• A Reddit user with a 2016 Rogue and code P0456 confirmed the fix: 'It was the Vapor Canister Vent Valve. I replaced it myself. It's located behind the wheel well, on the rear passenger side. The O-rings are known to go bad.'

Mechanic-Grade Diagnostic Values

• EVAP Canister Vent Control Valve Solenoid Resistance — expected: 20 - 50 Ohms. Failure: A reading of 0 Ohms (short circuit) or infinite/OL (open circuit) indicates a failed solenoid coil.
• EVAP Canister Purge Valve Solenoid Resistance — expected: Approximately 30 - 36 Ohms at room temperature.. Failure: A reading significantly outside this range, or showing open/shorted, indicates a bad valve coil. Resistance will vary with temperature.

Scan Tool Commands That Help

• Nissan CONSULT or advanced bidirectional scanner (e.g., Autel): EVAP System Leak Test / Active Test — This function is used to command the EVAP vent control valve to close, sealing the system. This is a required step before performing a smoke test or a vacuum decay test to ensure the system is sealed for an accurate diagnosis.
• Nissan CONSULT or advanced bidirectional scanner: Vent Valve Actuation Test (On/Off) — This command toggles the vent valve on and off, allowing a technician to listen for an audible 'click'. The absence of a click indicates the valve's solenoid is not functioning, confirming the need for replacement.

Wiring & Ground Locations

• EVAP Vent Control Valve Connector — At the EVAP canister, typically located at the rear of the vehicle near the passenger side wheel well.. This connector provides power and ground to the vent valve solenoid. One pin should have 12V with the key on, and the other is a ground controlled by the ECM. Verifying power and the ECM's ability to command the ground is crucial if a new valve doesn't work.
• ECM/Powertrain Grounds — Multiple locations in the engine compartment, such as on the engine block or inner fender. Specific locations for a 2019 Murano are detailed in factory service manuals and wiring diagrams.. A poor ground connection for the Engine Control Module (ECM) can cause erratic behavior in sensors and actuators, potentially leading to false trouble codes. While not a common cause for P0456, it's a foundational check for any electronic issue.

Real Owner Repair Stories

• Ace Tech Auto YouTube Channel (2017 Nissan Rogue (shares platform and EVAP components with Murano)) — Check Engine Light with code P0456.
  ❌ Tried (didn't work) Customer replaced the gas cap.
  ✅ What actually fixed it The technician used a scan tool to actuate the vent valve and heard no click. He plugged in a new valve and it clicked loudly when commanded. Replacing the EVAP canister vent valve resolved the code.
• YouTube diagnostic video (2015 Nissan Murano (Z52 generation)) — P0456 (Small Evap Leak Detected).
  ✅ What actually fixed it Using a smoke machine with a flow gauge, the technician energized the vent solenoid but the system would not hold pressure, indicating the valve was leaking internally. The fix was to order and replace the vent solenoid.

"I Checked Everything" — The Actual Cause

• In some cases, a vehicle can pass a physical smoke test (showing no visible leaks) but still set a P0456 code. One potential cause is a faulty Fuel Tank Pressure (FTP) sensor providing incorrect readings to the computer, making it believe a leak exists when one does not.
• Another rare possibility after a passed smoke test is a software glitch in the Powertrain Control Module (PCM/ECM). Some manufacturers have issued software updates (reflashes) to correct overly sensitive EVAP monitor logic that could falsely trigger a P0456 code.

OEM Part Supersession History

• 14935-JF00A, 14935-JF00B, 14935-JF00C, 14935-JF00D, 14935-JF00E → 14935-JF02C — Part has been revised multiple times by the manufacturer to improve reliability.
  Heads up: The latest part number, 14935-JF02C, is the recommended replacement for all previous versions and is broadly compatible with many Nissan/Infiniti models from this era.