Failed purge solenoid valve (open or shorted coil); Damaged, corroded, or disconnected wiring or connector at the purge valve; Blown fuse or faulty relay supplying power to the purge valve circuit; Open or shorted control wire between the purge valve and the engine computer; Faulty engine computer driver for the purge circuit (rare); Contamination or mechanical sticking inside the purge valve

DTC codes / P04xx · Auxiliary emission controls / P0443

P0443EVAP Purge Control Valve Circuit Malfunction

Q: What does code P0443 mean?

EVAP Purge Control Valve Circuit Malfunction. P0443 means the engine computer has detected an electrical fault in the circuit that controls the EVAP purge valve, which is the solenoid that meters fuel vapor from the charcoal canister into the intake. The computer monitors the voltage or current on the control wire and sets this code when the signal falls outside the expected range for the commanded state.

P0443 means the engine computer has detected an electrical fault in the circuit that controls the EVAP purge valve, which is the solenoid that meters fuel vapor from the charcoal canister into the intake. The computer monitors the voltage or current on the control wire and sets this code when the signal falls outside the expected range for the commanded state.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illuminated check engine light, often with no other symptoms
A slight fuel smell around the vehicle, especially after refueling
Rough idle or stumble if the purge valve sticks open and allows unmetered vapor into the intake
Failed emissions inspection due to the check engine light
Occasional hard starting after fueling if the canister is loaded with vapor

Common causes, most likely first

Failed purge solenoid valve (open or shorted coil)
Damaged, corroded, or disconnected wiring or connector at the purge valve
Blown fuse or faulty relay supplying power to the purge valve circuit
Open or shorted control wire between the purge valve and the engine computer
Faulty engine computer driver for the purge circuit (rare)
Contamination or mechanical sticking inside the purge valve

How to diagnose and fix it

Scan all modules and record freeze-frame data to confirm P0443 is the only purge-related code
Inspect the purge valve connector and harness for corrosion, chafing, or loose pins
Measure resistance across the purge solenoid coil and compare to the manufacturer's specification
Check for battery voltage at the purge valve supply wire with the key on and verify the ground or control signal
Command the purge valve on and off with a scan tool and listen for an audible click
Test the control wire for continuity and shorts to ground or power between the valve and computer
Replace the purge valve if electrically faulty, then clear codes and verify the monitor runs to completion

What the purge valve circuit test really checks

A P0443 is an electrical circuit code, so a valve that is mechanically stuck open or closed but still has a good coil will not set this code by itself.
Many technicians replace the purge valve only to find a corroded connector pin or a rubbed-through wire a few inches up the harness, so always inspect the wiring first.
Some vehicles share the purge valve power feed with other solenoids or relays, so a blown fuse can disable several circuits and set companion codes.
A purge valve that sticks open can cause a rough idle and fuel smell without ever setting P0443, because the computer sees normal electrical current but cannot detect the mechanical fault.
After any repair, the EVAP monitor may take several drive cycles to run, so a cleared light does not guarantee the fix until the monitor completes.

Can I keep driving with P0443?

The vehicle is generally safe to drive with P0443 because the fault affects emissions rather than engine operation, but avoid topping off the fuel tank and address the code promptly to prevent vapor leaks and a failed emissions test.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.