P0444
Evaporative Emission Control System Purge Control Valve Circuit Open
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The P0444 code is more specific than P0443—it tells you the ECM has detected an open circuit condition in the EVAP purge control valve wiring. An open circuit means there is a break somewhere in the electrical path, so the purge valve is receiving no power or no ground signal. This prevents the valve from operating at all, meaning fuel vapors stored in the charcoal canister cannot be purged into the engine for combustion.
Symptoms are typically minimal. The most obvious sign is the Check Engine Light. Some drivers may notice a faint fuel smell as vapors that should be purged into the engine instead accumulate. The vehicle will drive normally but won't pass an emissions test.
This is one of the easier EVAP codes to diagnose because the problem is clearly electrical. Start by inspecting the connector at the purge solenoid—it may simply be unplugged. Check the fuse that powers the EVAP circuit. Use a multimeter to check for continuity in the wiring from the ECM to the solenoid. If the wiring is intact, measure the solenoid coil resistance; an infinite reading (OL on a multimeter) confirms the coil is burned open and the solenoid needs replacement. This is typically a quick, inexpensive repair.
Severity
Symptoms
- •Check Engine Light is on
- •Possible faint fuel odor
- •Slightly rough idle in some vehicles
- •Minor decrease in fuel economy
- •Failed emissions inspection
Likely Causes
A broken or disconnected wire between the ECM and the purge solenoid creates an open circuit, preventing the valve from receiving power or ground signals.
The purge solenoid's internal electromagnetic coil has burned open, creating infinite resistance and preventing the valve from being energized.
The electrical connector at the purge solenoid has become corroded, loosened, or completely disconnected, breaking the circuit.
The fuse providing power to the purge solenoid circuit has blown, creating an open circuit from the power supply side.
The output driver within the ECM that controls the purge valve has failed open, though this is rare and should be diagnosed last.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Repair or replace open wiring in the purge valve circuit
- Replace the EVAP purge solenoid
- Clean and reconnect corroded connectors
- Replace blown fuse
- Repin loose connector terminals
Shop Parts
Videos
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