P0443Powertrain
Powertrain · SAE
EVAP Purge Valve — Circuit Electrical Fault
Meaning
The ECU detects an electrical anomaly in the EVAP purge valve control circuit (short circuit, open circuit, or voltage out of range). The valve cannot be operated correctly.
Common causes
- Short to ground or to power in the valve control wiring
- Open circuit (broken wire or disconnected connector)
- Purge valve coil shorted or open
- Damaged ECU driver for the purge valve
- Corroded connector or pushed-back pins at the valve connector
Symptoms
- Malfunction indicator lamp (MIL) on
- EVAP system inoperative: fuel vapors not purged
- Possible fuel odor in the engine bay
- Elevated evaporative emissions
- Sometimes rough idle if the valve is stuck open
Severity
Moderate: the engine runs but the EVAP system is disabled, causing evaporative emissions above regulatory limits.
What to do
- Measure purge valve coil resistance at the connector (typically 22–32 Ω; open or short indicates a valve replacement)
- Check supply voltage and PWM control signal at the valve connector
- Inspect wiring for shorts to ground, shorts to power, or breaks
- Check connector for corrosion or pushed-back pins
- Replace the purge valve or repair the wiring according to findings