P2405: EVAP Leak Detection Pump Sense Circuit Low
The P2405 code indicates that the Engine Control Module (ECM) has detected a low voltage signal from the Evaporative Emission (EVAP) leak detection pump sense circuit. This pump is part of the EVAP system's leak detection module, which pressurizes the system to check for leaks. A low voltage reading suggests a short to ground, open circuit, or faulty pump assembly, preventing proper leak detection and potentially causing EVAP system malfunctions.
01. Most Common Causes
- Faulty EVAP leak detection pump assembly
- Open or shorted sense circuit wiring
- Corroded or loose electrical connector at pump
- Failed ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed EVAP system leak test
- Possible fuel odor
- No noticeable drivability issues
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P2405 and check for related EVAP codes.
Step 2: Visually inspect the EVAP leak detection pump connector and wiring for damage, corrosion, or loose connections.
Step 3: Test the pump's sense circuit voltage with a multimeter (should be near battery voltage with key on).
Step 4: If voltage is low, disconnect the pump and check for continuity to ground; if shorted, repair wiring.
Step 5: If wiring is okay, replace the EVAP leak detection pump assembly.
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 function properly, which may cause a failed emissions test and increased fuel vapor release.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including parts (pump assembly $100-$250) and labor ($50-$150).