P0448: EVAP System Vent Control Circuit Shorted
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - but a vent valve stuck shut can make the tank difficult to refuel.
Symptoms
- Check engine light
- Fuel pump nozzle clicking off repeatedly
- Emissions test failure
Likely causes, most common first
- Vent valve control circuit shorted
- Valve seized closed by dirt or corrosion
- Wiring damaged under the vehicle
- Failed valve winding
Read P0448 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P0448 is the short-circuit version of the vent valve fault. If the valve ends up held closed, the tank cannot breathe while being filled, and the pump nozzle shuts off every few seconds as pressure builds - a memorable symptom that points straight at this part.
Because the valve sits low on the vehicle and draws air through a filter, dirt and spider webs genuinely do seize them. Some designs have a separate air filter for the canister that is worth checking at the same time; a blocked one produces similar complaints without any electrical fault at all.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P0448
“The "check engine light" came on. The code associated with the issue is p0448. The problem is with the evap canister vent control valve. We are the original car owners.”2010 Nissan Altima · Aug 2015 · 36,433 mi
“The "check engine light" came on. The code associated with the issue is p0448. The problem is with the evap canister vent control valve. We are the original car owners.”NHTSA complaint · Aug 2015 · 36,433 mi
“I took my truck to temecula nissan and had it check, they told me my air bag would not open if I was in an accident, faulty spiral cable-p1564,faulty vent control valve-p0448, faulty fuel tank sending unit- p0463 this are things that need to be fixed, some of them are on a recall list but I was told it expired. So I could die behind this. *cn”2007 Nissan Frontier · Jun 2015 · 150,000 mi
Show 2 more owner reports
“While driving, service engine soon light appeared with code p0448. After code appeared, cannot fill up gas tank without gas spilling out. Called dealer and they said this is unrelated. *tr”2009 Nissan Frontier · Dec 2011 · 42,000 mi
“I purchased vehicle in mid 2009. Gas gauge failure causes abrupt stops without notice in heavy traffic areas causing hazardous situation and potential direct harm to driver and passengers. Nissan has been aware of faulty fuel sending unit prior to purchase of vehicle. As a buyer, I was not informed of problem with vehicle when car purchased at use car dealership (k & j auto sales ) located in hayward, california. Nissan factory recall and technical service bulletins for code p0463 and p0448 were issued for vehicle prior to purchase. This is an inherent problem in car design with previous xterra models as it has been documented in publications.. *tr”2006 Nissan Xterra · Nov 2011 · 80,000 mi
Cars that report P0448 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P0448?
Yes - but a vent valve stuck shut can make the tank difficult to refuel.
How much does it cost to fix P0448?
Typical US repair costs range from $80 for the simplest fix (vent control valve) to $400 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P0448. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.