P0448
EVAP System Vent Control Circuit Shorted
EVAP vent valve drive circuit shorted to ground or B+. The vent valve seals the canister during pressure-test diagnostics.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Common causes
Ordered by how often each turns out to be the cause.
- Short in drive lineCommon
Parts involved
- EVAP Vent Valve
P0448 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.