EVAP Leak Detection Pump Control Circuit Low
The P2401 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the control circuit of the Evaporative Emission (EVAP) system leak detection pump. This pump is part of the EVAP system's diagnostic module, which tests for fuel vapor leaks. A low voltage signal suggests a short to ground, open circuit, or a faulty pump assembly, preventing the system from performing leak tests.
01. Most Common Causes
- Faulty EVAP leak detection pump
- Open or shorted wiring in the pump control circuit
- Corroded or loose electrical connector at the pump
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed EVAP system leak test (monitor not ready)
- Possible fuel odor
- No noticeable drivability issues
03. Step-by-Step Diagnosis
Step 1: Connect a scan tool and verify the code. Check for other EVAP codes.
Step 2: Visually inspect the leak detection pump and its wiring for damage, corrosion, or loose connections.
Step 3: Using a multimeter, test the pump control circuit for voltage and continuity. Compare to manufacturer specifications.
Step 4: If circuit is good, test the pump resistance and operation. Replace pump if faulty.
Step 5: Clear codes and perform a drive cycle to verify repair.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but the EVAP system will not perform leak tests, and you may fail an emissions inspection. The Check Engine Light will remain on.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including parts and labor. The leak detection pump itself costs $50-$150, plus diagnostic time.