P0448 on 2015-2018 Nissan Murano: EVAP Vent Control Circuit Shorted Causes and Fixes

What's Unique About the 2015-2018 Nissan MURANO

For the 2015-2018 Nissan Murano, the P0448 code is frequently not a hardware problem. Nissan issued multiple Technical Service Bulletins (TSBs) indicating that due to calibration errors, the Engine Control Module (ECM) can improperly store a permanent P0448 trouble code. TSB NTB19-045b explicitly states that the reprogram is not a fix for the DTC itself, but an update to how the permanent DTC is stored and allowed to be erased after the actual fault (e.g., a bad valve or wiring) has been properly diagnosed and repaired. This nuance is critical; the TSB should be performed *after* any hardware repair is completed.

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
• Possible faint fuel smell near the rear of the vehicle
• Difficulty filling the gas tank (fuel pump nozzle clicks off repeatedly).
• Failure to pass an emissions inspection.
• In rare cases, a rough idle or difficulty starting immediately after refueling.

Most Likely Causes

1. ECM Software Calibration Error 🔴 High Probability Nissan has officially documented this issue in TSBs #NTB19-045b and #P9328_P9343_P934, stating the ECM may improperly store a permanent diagnostic trouble code due to calibration errors. This affects many Nissan models with the VQ35DE engine from this era.
   How to confirm: A Nissan dealership can check your vehicle's VIN against their database to see if the TSB applies and if the software update has been performed. The TSB applies if the stored ECM part number matches the list in the bulletin.
   Typical fix: Reprogramming the Engine Control Module (ECM) with updated software. This is done *after* confirming the rest of the EVAP vent circuit is functioning correctly.
   Est. part cost: $100-$250
2. Faulty EVAP Canister Vent Control Valve 🟡 Medium Probability → Shop Vapor Canister Vent Valve The vent valve is located under the vehicle near the charcoal canister, exposed to road debris and moisture, which can cause it to fail, its electrical contacts to corrode, or for the plunger to get stuck.
   How to confirm: Inspect the valve and connector for corrosion or damage. Test the solenoid's resistance with a multimeter; a good valve typically reads between 20-30 ohms. Apply 12V power to the valve's terminals and listen for an audible click, which indicates the solenoid is activating. 🎬 Watch: A helpful guide on diagnosing and fixing P0448. If it doesn't click, the internal coil is likely open and the valve is bad.
   Typical fix: Replace the EVAP canister vent control valve/solenoid. This involves twisting the old valve about 45 degrees counter-clockwise to release it from the canister.
   Est. part cost: $50-$120
3. Damaged Wiring or Connector ⚪ Low Probability The wiring harness leading to the vent control valve can be damaged by road debris, chafing against the chassis, or corrosion, causing a short or open circuit.
   How to confirm: Visually inspect the wiring harness from the ECM to the vent valve for any breaks, chafing, or corrosion. With the key on, one wire at the connector should have 12V power. Check for continuity to ground on the other wire while using a scan tool to command the valve on/off.
   Typical fix: Repair or replace the damaged section of the wiring harness or the connector.
   Est. part cost: $10-$50
4. Clogged EVAP Canister or Vent Hose ⚪ Low Probability → Shop Vapor Canister Dirt, dust, or even insects can clog the fresh air vent hose or the charcoal canister itself, preventing the system from breathing properly. This can cause the vent valve to stick or report a fault. Some Nissan models had TSBs for installing an extra filter to prevent this.
   How to confirm: Remove the vent valve and hoses from the charcoal canister and inspect for blockages. Attempt to blow low-pressure compressed air through the canister's ports to check for flow. If it's clogged with dirt, it may be possible to clean it out.
   Typical fix: Clean out the blockage from the hoses or replace the charcoal canister if it is internally clogged and cannot be cleared.
   Est. part cost: $0-$250

Rare But Worth Checking

• Faulty Engine Control Module (ECM): → Shop Engine Control Module (ECM) This is very rare. If the software reprogram has been done and all wiring and components test good, a hardware failure within the ECM's driver circuit is a remote possibility. This would require sending the ECM for repair or replacement.

Diagnosis Steps

1. Scan the vehicle for any other stored trouble codes. Note if P0447 is also present.
2. Check with a Nissan dealer using your VIN to see if TSBs NTB19-045b or P9328_P9343_P934 apply. Confirm if the ECM reprogram has ever been performed.
3. Locate the EVAP canister and vent control valve at the rear of the vehicle, typically on the driver's side near the spare tire area.
🎬 Watch: See exactly where the vent valve is located.
4. Visually inspect the vent valve connector and wiring harness for any signs of physical damage, corrosion, or loose connections.
5. Disconnect the valve. With the ignition ON, use a multimeter to confirm one terminal of the connector has battery voltage (approx. 12V).
6. Test the valve's internal resistance with a multimeter. A typical reading should be between 20-30 ohms. An open circuit (infinite resistance) or a dead short (zero resistance) indicates a failed valve.
7. Bench test the valve by applying 12V and ground to its terminals. Listen for a distinct 'click'. No click means the solenoid is seized or burned out.
8. If the valve and wiring seem functional, inspect the vent hoses and the charcoal canister ports for any blockages from dirt, dust, or spider webs.
9. If a hardware fault is found and repaired (e.g., new vent valve), clear the codes. If the P0448 code returns as a permanent DTC, a dealer visit for the TSB software update is necessary to allow the code to be properly erased.

Parts You'll Likely Need

• EVAP Canister Vent Control Valve (OEM #14935-JF00E) — This is the most common hardware component to fail, either by getting stuck, shorting internally, or having its function impeded by debris.
  Trusted brands: Nissan (OEM), Dorman, Bosch, APA/URO Parts
  OEM price range: $60-$90
  Aftermarket price range: $40-$70

Related Codes That Often Appear With This One

• P0087 — Mentioned in the same TSBs (NTB19-045b, P9328_P9343_P934) as being potentially caused by the same ECM software glitch.
• P0101 — Mentioned in the same TSBs (NTB19-045b, P9328_P9343_P934) as being potentially caused by the same ECM software glitch.
• P2008 — Mentioned in the same TSBs (NTB19-045b, P9328_P9343_P934) as being potentially caused by the same ECM software glitch.
• P0447 — This code for 'EVAP Vent Control Circuit Open' is often seen with P0448 as they both point to an electrical fault in the same circuit, just a different type (open vs. short).

Technical Service Bulletins (TSBs) & Recalls

• NTB19-045b: 'MIL ON WITH DTC P0087, P0101, P0448, OR P2008, VEHICLES REGISTERED OUTSIDE OF CALIFORNIA'. This TSB is key, explaining that an ECM reprogram is needed to update how permanent DTCs are stored and erased after a repair.
• P9328_P9343_P934: A similar campaign for vehicles in California, also mentioning reprogramming the ECM for a permanent DTC P0448 due to calibration errors.
• NTB19-045a: An earlier version of NTB19-045b.
• NTB19-045: The original version of the TSB. []

Platform-Specific Known Issues

• A primary issue for the 2015-2018 Murano is an ECM calibration error that can cause a false P0448 code to be stored permanently. This is documented in Nissan TSBs #NTB19-045b and #P9328_P9343_P934 and requires a software update from a dealer. The TSB clarifies the update is to correct the logic for storing and clearing the permanent code *after* a physical repair has been made.
• Some owners on forums for related Nissan vehicles have fixed a persistent P0448 by removing the charcoal canister and blowing out a significant amount of dust and debris that had accumulated inside, which prevented the vent valve from operating correctly.

Mechanic-Grade Diagnostic Values

• EVAP Canister Vent Control Valve Solenoid Resistance — expected: 15 - 30 Ohms. Failure: A reading of 0 Ohms (dead short) or infinite resistance (open circuit) indicates a failed solenoid.
• Voltage at Vent Control Valve Connector — expected: Approximately 12V (battery voltage) on one pin with ignition ON.. Failure: No voltage suggests a wiring issue or blown fuse upstream. The other pin is a ground controlled by the ECM.

Scan Tool Commands That Help

• Nissan CONSULT or compatible bidirectional scanner: EVAP System Test / Vent Valve Activation — This active test allows the technician to command the normally-open vent valve to close. Listening for an audible 'click' from the valve confirms the ECM, wiring, and solenoid coil are functioning electrically. This is a crucial step to differentiate a circuit fault from a mechanically stuck valve or a blockage.

Wiring & Ground Locations

• EVAP Canister Vent Control Valve — Mounted directly on the charcoal canister, which is located under the rear of the vehicle, often near the spare tire area.. This is the component and circuit that the P0448 code directly refers to. Its location exposes it to road debris and moisture, making its connector and wiring a primary inspection point for shorts, corrosion, or damage.
• ECM (Engine Control Module) — Located in the engine compartment, typically on the driver's or passenger's side against the firewall.. The ECM provides the switched ground signal that activates the vent control valve. While rare, a fault in the ECM's internal driver circuit can cause a P0448 code. The TSB-related software issue also resides within the ECM.

Real Owner Repair Stories

• The Nissan Path forum user (Nissan Pathfinder (similar EVAP system design)) — Continuous P0448 code that would return shortly after being reset.
  ❌ Tried (didn't work) Replacing the EVAP canister vent control valve.
  ✅ What actually fixed it The owner removed the charcoal canister, blew compressed air through the ports, and a large amount of fine dust came out. Cleaning the dust blockage from the canister resolved the code without replacing the canister itself.

"I Checked Everything" — The Actual Cause

• A P0448 code is a 'circuit shorted' code, not a leak code (like P0455 or P0456). Therefore, a smoke test will almost always come back clean (no leaks) because the test is designed to find physical leaks, not electrical faults. The root cause is an electrical issue in the vent valve circuit (bad valve solenoid, shorted wire) or a valve that is physically stuck closed, which would also pass a smoke test but prevent the system from venting.

OEM Part Supersession History

• 14935-JF00A, 14935-JF00B, 14935-JF00C, 14935-JF00D → 14935-JF00E, which may also be superseded by 14935-JF02C — Revisions to improve durability and prevent sticking or internal failure.
  Heads up: The listed part numbers are generally cross-compatible for this application. Always verify with VIN.

Model Year Variations Within This Range

• 2018: For the 2018 model year, Nissan made Forward Collision Warning, Automatic Emergency Braking, and an 8-inch navigation screen with Apple CarPlay/Android Auto standard on all trims. While this doesn't directly affect the P0448 code, it's a notable change in the vehicle's standard equipment within the specified year range.