P0448: Evaporative Emission Control System Vent Control Circuit Shorted
Low SeveritySafe to drive (short-term)EVAP System
P0448 means the ECU detected a short circuit on the EVAP vent control valve. The vent valve seals the charcoal canister during EVAP system self-testing. A shorted circuit usually points to a chafed wire grounding against the chassis, a failed solenoid with an internally shorted coil, or a damaged connector.
Estimated repair costFrom €60 to €600+, varies by vehicle
What does P0448 mean?
P0448 means the ECU detected a short circuit on the EVAP vent control valve. The vent valve seals the charcoal canister during EVAP system self-testing. A shorted circuit usually points to a chafed wire grounding against the chassis, a failed solenoid with an internally shorted coil, or a damaged connector.
P0448 is a evap system-related diagnostic trouble code classified as low severity. When your vehicle's ECU detects this condition, it stores P0448 and illuminates the check engine light.
What are the symptoms of P0448?
If your vehicle has triggered P0448, you may notice one or more of these symptoms:
Check engine light illuminated
Possible fuel cap warning on some vehicles
Failed emissions test
No noticeable driveability issues
May appear alongside P0440 or other EVAP codes
What causes P0448?
Here are the most common causes of P0448, ranked by how likely they are to be the culprit:
highChafed wire shorting to chassis ground
highInternally shorted vent valve solenoid coil
mediumWater intrusion into the vent valve connector
mediumDamaged harness near the rear subframe or fuel tank
lowFailed ECU driver circuit
Is it safe to drive with P0448?
Generally yes, for short-term driving. P0448 is an electrical fault on the EVAP vent valve circuit and has no effect on engine performance or safety. Drive normally, but expect a failed emissions inspection until repaired.
How do you diagnose P0448?
Follow these steps to pinpoint the root cause of P0448:
Disconnect the EVAP vent valve and measure solenoid resistance. A reading below 15 ohms (or near zero) indicates a shorted coil and a failed valve
Inspect the harness from the ECU to the vent valve for chafing, especially where it crosses the rear subframe, exhaust heat shields, or the fuel tank straps
Check the vent valve connector for water intrusion. Pull the boot back and look for corrosion or moisture inside the pins. Dry, clean, and apply dielectric grease
With the valve disconnected and the harness unplugged at the ECU side, use a multimeter to check for continuity between the signal wire and chassis ground. Continuity means the wire is shorted
If wiring and resistance check out, use a scan tool to command the valve and verify the ECU drive signal with an oscilloscope. A weak or shorted ECU driver is rare but possible after years of repeated valve failures
How much does P0448 cost to fix?
Repair costs for P0448 vary depending on the root cause and your vehicle. Here are typical estimates:
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Repair shorted wire or harness section
€10–€40
€50–€150
€60–€190
Moderate
Replace EVAP vent valve solenoid
€40–€150
€30–€80
€70–€230
Moderate
Replace charcoal canister assembly with integrated valve
€100–€400
€80–€200
€180–€600
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0448 on specific vehicles
P0448 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
P0448 on BMW 3 Series
BMW 3 Series • 2005–2024
BMW E90/F30 vehicles use the leak detection pump assembly with an integrated vent valve. P0448 is less common than P0447 on these vehicles but typically points to harness damage between the LDP and the body control module. The LDP itself is rarely the cause of a short, more often the cause of an open.
What causes P0448 on a BMW 3 Series?
BMW 3 SeriesHarness damage between LDP and body control module
BMW 3 SeriesWater intrusion into LDP connector on high-mileage vehicles
P0448 repair cost for BMW 3 Series
Estimated costs for BMW 3 Series ownersadjusted higher than average due to BMW-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Repair shorted wire or harness section
€14–€56
€70–€210
€84–€266
Moderate
Replace EVAP vent valve solenoid
€56–€210
€42–€112
€98–€322
Moderate
Replace charcoal canister assembly with integrated valve
€140–€560
€112–€280
€252–€840
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0448 on Volkswagen Golf
Volkswagen Golf • 2005–2024
On Mk5 and Mk6 Golf the vent valve harness runs along the underbody and is exposed to road debris. Chafing where the harness crosses the rear subframe is a known cause of P0448. Inspect carefully with the vehicle on a lift before condemning the canister.
What causes P0448 on a Volkswagen Golf?
Volkswagen GolfHarness chafing at the rear subframe crossover on Mk5/Mk6
Volkswagen GolfShorted N115 vent valve coil on high-mileage TSI models
P0448 repair cost for Volkswagen Golf
Estimated costs for Volkswagen Golf ownersadjusted higher than average due to Volkswagen-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Repair shorted wire or harness section
€12–€46
€57–€173
€69–€218
Moderate
Replace EVAP vent valve solenoid
€46–€173
€35–€92
€81–€265
Moderate
Replace charcoal canister assembly with integrated valve
€115–€460
€92–€230
€207–€690
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0448 on Audi A4
Audi A4 • 2005–2024
The B7 and B8 A4 share the underbody harness routing with the VW Golf. P0448 on these vehicles often follows winter driving in salt-treated regions like Germany, Poland, or Lithuania. Inspect the connector and harness near the rear axle before replacing parts.
What causes P0448 on a Audi A4?
Audi A4Connector corrosion from road salt on B7/B8 underbody
Audi A4Internally shorted N115 vent valve coil
P0448 repair cost for Audi A4
Estimated costs for Audi A4 ownersadjusted higher than average due to Audi-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Repair shorted wire or harness section
€13–€50
€63–€188
€75–€238
Moderate
Replace EVAP vent valve solenoid
€50–€188
€38–€100
€88–€288
Moderate
Replace charcoal canister assembly with integrated valve
€125–€500
€100–€250
€225–€750
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0448 on Ford Focus
Ford Focus • 2005–2024
The Focus Mk2 and Mk3 canister vent solenoid harness is routed close to the rear suspension. Wagon variants are especially prone to chafing where the harness flexes with suspension travel. A simple harness wrap and clip relocation often resolves recurring P0448 codes after the original repair.
What causes P0448 on a Ford Focus?
Ford FocusHarness chafing at rear suspension on Mk3 wagon
Ford FocusShorted canister vent solenoid coil
P0448 repair cost for Ford Focus
Estimated costs for Ford Focus ownersadjusted lower than average due to Ford-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Repair shorted wire or harness section
€9–€36
€45–€135
€54–€171
Moderate
Replace EVAP vent valve solenoid
€36–€135
€27–€72
€63–€207
Moderate
Replace charcoal canister assembly with integrated valve
€90–€360
€72–€180
€162–€540
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related diagnostic codes
These codes are often seen alongside P0448 or indicate related issues:
Both codes refer to the EVAP vent valve circuit, but P0447 indicates an open circuit (no current flow) while P0448 indicates a short (too much current flow). The diagnostic process is similar, but P0448 is more often a chafed wire grounding against the chassis.
Will P0448 damage my engine?
No. P0448 is purely an emissions and electrical fault. It does not affect fuel delivery, ignition, or any system that could cause mechanical damage. The only practical consequence is a failed emissions inspection and the check engine light.
Why did P0448 appear after work near the fuel tank?
Recent service near the fuel tank, exhaust, or rear suspension can disturb the vent valve harness. A pinched or chafed wire is a common after-service cause. Have the workshop that did the work re-inspect the harness routing free of charge if the code appeared within days.
Can I just clear P0448 and ignore it?
You can clear it, but it will return within one drive cycle if the short is still present. Ignoring it long-term means a permanent check engine light, automatic emissions test failure, and the possibility of related codes piling up as the ECU loses its EVAP self-test capability.
Scan your car with Skanyx to diagnose P0448
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