P0443: Evaporative Emission System Purge Control Valve Circuit Malfunction

What does the P0443 error code mean?

The P0443 diagnostic trouble code indicates an "Evaporative Emission System Purge Control Valve Circuit Malfunction." This code is triggered when the engine control module detects an issue in the electrical circuit that controls your car’s purge valve. The purge valve is a component of the evaporative emissions control (EVAP) system, which prevents fuel vapors from escaping into the atmosphere by routing them back into the engine for combustion. Other causes can include damaged or corroded wiring, loose connections, or a bad powertrain control module.

Why it's important to address P0443

The EVAP system is essential for reducing harmful emissions and ensuring the vehicle complies with environmental regulations, which means your car could fail its next emissions test. A malfunction in the purge valve circuit can cause excessive emissions and may lead to increased fuel consumption or other performance issues since the vehicle is no longer burning the vapors within the engine. Ignoring this issue may result in damage to the EVAP system, rough idling, worse fuel economy, and in severe cases, stalling.

Can I safely drive my car with this error code?

Driving with the P0443 code is generally safe in the short term since it typically does not affect immediate drivability, though it's not recommended. The vehicle may produce higher emissions, run less efficiently, and fail an emissions test.

Common symptoms of the P0443 error code

• Check engine light illuminated

• Reduced fuel efficiency

• Difficulty starting the engine

• Strong fuel odor near the vehicle

• Increased emissions detected during testing

• Stalling (in severe cases)

How to diagnose the P0443 error code

Diagnosing the P0443 code typically involves:

• Scan for codes: Use an OBD-II scanner to confirm the P0443 code and identify any related codes.

• Inspect the purge valve: Check the purge valve for signs of damage, clogging or malfunction.

• Test electrical circuit: Measure the voltage and continuity in the purge valve circuit using a multimeter.

• Inspect wiring and connectors: Look for damaged, corroded, or disconnected wiring and connectors in the EVAP system.

• Test the engine control module signal: Verify that the engine control module is sending the correct signals to the purge valve.

• Perform a smoke test: Check for leaks in the EVAP system that could be related to the issue.

How to repair the P0443 error code

Repairing the P0443 code typically involves:

• Replacing a faulty purge valve.

• Repairing or replacing damaged wiring or connectors in the purge valve circuit.

• Cleaning or unclogging the purge valve if it is restricted.

• Replacing a malfunctioning engine control module if it is determined to be the cause.

• Clearing the code and conducting a test drive to ensure the repair is successful.

Related reading

Follow the link below to reach our diagnostic check engine trouble codes catalog:
On-board diagnostics (OBD-II) trouble code directory