P0443 – Meaning, Causes, Symptoms, & Fixes

Code P0443 Definition

Evaporative Emission Control System Purge Control Valve Circuit Malfunction

What Does P0443 Mean?

The evaporative control (EVAP) system collects raw fuel escaping from the fuel tank. This information is then communicated to the ECM which regulates the emissions of the vehicle. The P0443 code is set when the ECM detects a malfunction within the purge control valve or a short in the purge valve circuit.

P0443 Symptoms*

*No noticeable adverse conditions in some cases

P0443 Causes

  • Short in control circuit wiring
  • Short in purge valve wiring
  • Faulty vent valve solenoid
  • Faulty purge valve solenoid
  • Faulty ECM

Code P0443 Severity – Low

This trouble code will not prevent your vehicle from operating, but may cause it to fail emissions tests. The most common error(s) include: lowered fuel economy and rough engine performance. It is recommended to have this code fixed to prevent further loss of fuel economy.

Code P0443 Common Diagnosis Mistakes

Prematurely replacing the purge control valve when the issue lies within the wiring or connectors which could have been diagnosed by inspection.

P0443 Diagnosis

  • Tools Needed to Diagnose:
    • FIXD

Difficulty of Diagnosis and Repair

  1. Check to see if there are any other codes along with P0057 and clear your Check Engine Light with FIXD.
  2. Check the freeze frame data and monitor in an attempt to pinpoint the issue.
  3. Using FIXD, monitor the fuel tank pressure readings to ensure the fuel tank pressure sensor is properly functioning.
  4. The fuel tank pressure sensor provides the primary feedback on engine leaks to the EVAP system of your vehicle.
  5. Verify the fuel cap is not cracked and ensure it is tightly sealed to the vehicle.
  6. Visually inspect the wiring around the purge valve circuit for disconnection.
  7. Confirm the purge control valve and vent valve are properly functioning and holding vacuum for at least half a minute.
  8. If the problem persists, consider replacing the faulty valve.
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