Staff Answer
Jul 20, 2026 - 06:33 PM
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The P0443 code indicates an electrical fault in the circuit controlling the EVAP purge valve, which prevents fuel vapors from escaping into the atmosphere.
Method 1: Electrical Continuity & Fuse Check Since P0443 is a circuit code, it often stems from power loss or wiring issues rather than a bad valve.
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Inspect Wiring: Check the wire pigtail leading to the purge valve for signs of corrosion, fraying, or heat damage.
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Check Fuse: Refer to your owner's manual to locate the engine bay fuse box. Check the fuse labeled "ECM," "ENGINE," or "EVAP." A blown fuse will prevent the PCM from actuating the valve.
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Check Connector: Ensure the harness plug is fully seated and free of debris. Use electrical contact cleaner if you detect any oxidation.
Method 2: Solenoid Resistance & Function Test If the electrical supply is sound, the purge valve solenoid itself may be faulty.
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Resistance Test: With the engine off and the valve disconnected, use a multimeter set to ohms (Ω) to test the two pins on the valve. A healthy solenoid usually reads between 15–30 Ω. An "OL" (Open Loop) reading confirms an internal break in the coil.
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Vacuum/Click Test: Apply 12V power to the valve terminals using a bench power supply or jumper wires. You should hear a distinct "click" as the valve opens. If it does not click, the solenoid is failed and requires replacement.
Warning: Always disconnect the negative battery terminal before performing electrical repairs. Do not apply 12V power to the vehicle side of the harness to avoid damaging the PCM.
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