P2405 - EVAP Leak Detection Pump Sense Circuit Low
The P2405 code indicates that the Engine Control Module (ECM) has detected a low voltage condition in the sense circuit of the Evaporative Emission (EVAP) leak detection pump. This pump is part of the EVAP system's leak detection monitor, which pressurizes the fuel system to check for leaks. A low sense circuit voltage typically points to a faulty pump, wiring issues, or a poor electrical connection. This can prevent the EVAP system from properly detecting leaks, potentially causing increased emissions and triggering the Check Engine Light.
1. Most Common Causes
- Open or short-to-ground in the LDP sense circuit
- Damaged, corroded, or disconnected LDP connector
- Faulty Leak Detection Pump (LDP) (internal switch/sensor failure)
- Internal PCM failure (rare)
- Wiring harness issues (pinched, chafed wires)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible fuel odor
- No noticeable drivability issues
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the EVAP leak detection pump and its wiring for damage or corrosion.
Step 3: Test the pump's sense circuit voltage with a multimeter; compare to manufacturer specs.
Step 4: Check for continuity and shorts in the sense circuit wiring.
Step 5: If wiring is okay, replace the EVAP leak detection pump.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but the vehicle may fail an emissions test and the Check Engine Light will remain on. It is recommended to repair it soon to avoid potential fuel vapor leaks.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the vehicle and whether the pump or wiring needs replacement.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.