EVAP Purge Control Valve Circuit Malfunction
The P0443 code indicates a problem in the electrical circuit of the evaporative emission (EVAP) purge control valve. This valve regulates the flow of fuel vapors from the charcoal canister to the intake manifold for combustion. The powertrain control module (PCM) monitors the valve's circuit for opens, shorts, or excessive resistance. A fault can prevent proper purging, leading to increased emissions and potential drivability issues.
01. Most Common Causes
- Faulty purge control valve
- Open or shorted wiring in the purge valve circuit
- Corroded or loose electrical connector at the purge valve
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Possible rough idle or poor fuel economy
- Fuel smell from engine bay
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P0443 is present. Clear codes and retest to confirm.
Step 2: Visually inspect the purge valve connector and wiring for damage, corrosion, or loose connections.
Step 3: Use a multimeter to test the purge valve resistance (typically 10-30 ohms). Replace if out of spec.
Step 4: Check for battery voltage and ground at the valve connector with the engine running. If missing, repair wiring or PCM issue.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but it may cause rough idle, reduced fuel economy, and will likely fail an emissions test. It's best to repair promptly.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, depending on the valve cost and accessibility.