What causes fault code P0443?

• Most likely: Faulty EVAP purge control solenoid (internal short or open coil) • Likely: Damaged wiring harness or corrosion in the connector pins • Possible: Blown fuse providing power to the EVAP solenoid circuit • Rare: Failed Engine Control Unit (ECU) output driver

Powertrain (Engine & Gearbox)Standard EOBD

P0443 - Evaporative Emission System Purge Control Valve Circuit

Q: What are the symptoms of fault code P0443?

• Check Engine Light (MIL) illuminated • Slight fuel odor around the vehicle • Rough idle, especially shortly after refueling • Failed emissions test (readiness monitors won't set) • Minor decrease in fuel efficiency

Q: How do you fix fault code P0443?

STEP 1: Check fuses related to the EVAP system. Inspect the solenoid connector for corrosion or backed-out pins. STEP 2: Verify power supply. With ignition ON, there should be battery voltage (approx. 12.6V) at the harness plug. STEP 3: Measure the solenoid's internal resistance using a multimeter. Normal values are typically 10-30 Ohms. An 'OL' reading indicates a blown coil. STEP 4: Use a scan tool to perform an output state/actuation test. Listen for an audible click. Verify the ECU ground-side pulse (PWM) using an oscilloscope or logic probe. STEP 5: If wiring and power are verified but the valve is unresponsive or has incorrect resistance, replace the EVAP purge solenoid.

Last updated:1 February 2026

Related:EVAP Purge Valve / Spolningsventil, Charcoal Canister / Kolkanister, Engine Control Module (ECM/ECU), Wiring Harness

System

Powertrain (Engine & Gearbox)

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Exhaust Gas Recirculation Flow Malfunction

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Exhaust Gas Recirculation Flow Excessive Detected

P0403

Exhaust Gas Recirculation (EGR) Control Circuit

Technical Description

The P0443 code indicates an electrical malfunction within the Evaporative Emission (EVAP) system purge control valve circuit. The Engine Control Unit (ECU) monitors the integrity of the solenoid circuit by checking for expected voltage drops when the valve is commanded. The purge valve is a PWM-controlled (Pulse Width Modulation) solenoid that regulates the flow of fuel vapors from the charcoal canister to the intake manifold. This code triggers when the ECU detects an out-of-range electrical signal, such as an open circuit, short to ground, or short to power.

Possible Causes

Faulty EVAP purge control solenoid (internal short or open coil)

Damaged wiring harness or corrosion in the connector pins

Blown fuse providing power to the EVAP solenoid circuit

Failed Engine Control Unit (ECU) output driver

Symptoms

Check Engine Light (MIL) illuminated

Slight fuel odor around the vehicle

Rough idle, especially shortly after refueling

Failed emissions test (readiness monitors won't set)

Minor decrease in fuel efficiency

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P0443 - Evaporative Emission System Purge Control Valve Circuit

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P0443 - Evaporative Emission System Purge Control Valve Circuit

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