EVAP System Vent Control Circuit Shorted
What it means
The engine computer has detected a short in the vent valve circuit, to ground, to a voltage source or inside the valve coil. The valve may stay closed all the time, so pressure or vacuum builds in the tank and refueling becomes difficult.
Related lights
Dashboard lights that may come on with this code.
Symptoms4
- Check engine light on.
- Difficult refueling with the nozzle clicking off early if the valve stays closed.
- Occasional strong rush of air when opening the fuel cap.
- Usually no driving symptoms.
Possible causes5
- Internal short in the vent valve coil.
- Control wire chafed under the vehicle and shorted to ground.
- Water inside the connector.
- Control wire shorted to a nearby power wire.
- Faulty driver circuit inside the engine computer (rare).
How to diagnose5
- Measure the valve coil resistance; a very low reading means an internal short.
- Unplug the valve and see whether the code changes, which points to the valve itself.
- Check the control wire for a short to ground or to voltage.
- Check the connector for moisture or corrosion.
- Watch tank pressure on a scan tool to confirm the valve is not stuck closed.
How to fix5
- Dry and clean the connector or replace it.
- Repair the shorted wire and protect it from chafing.
- Replace the vent valve if its coil is shorted.
- Have the computer circuit checked if the fault returns after repairing the valve and wiring.
- Clear the codes and confirm the valve works with a scan tool.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
In the Saudi market: SAR 100–700 (≈ USD 27–187)
Our prices come from the Saudi market, converted at a fixed rate (SAR 3.75 per USD). Prices in your country may differ a lot, so we show the cost level.
The cost is low when a wire or connector is to blame, and rises when the vent valve near the tank is replaced.
Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026
Frequently asked questions
Why do I hear a rush of air when opening the fuel cap?
A vent valve stuck closed stops air entering the tank, so vacuum builds inside and is released as a rush of air when the cap is opened.
What is the difference between P0447 and P0448?
P0447 means the vent valve circuit is open. P0448 means there is a short in the circuit or inside the valve coil.
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