EVAP Leak Detection Pump Sense Circuit Open
The P2403 code indicates an open circuit in the Evaporative Emission (EVAP) system leak detection pump sense circuit. This pump is part of the EVAP system's leak detection module, which monitors for fuel vapor leaks. An open circuit means the electrical path to the pump's sense wire is broken, preventing the module from reading pump operation. This can be caused by a faulty pump, damaged wiring, or a blown fuse.
01. Most Common Causes
- Faulty EVAP leak detection pump
- Open or shorted wiring in the pump sense circuit
- Corroded or loose electrical connector at the pump
- Blown fuse related to the EVAP system
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Possible failed emissions test
- No noticeable drivability issues in most cases
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P2403 and check for other EVAP codes.
Step 2: Visually inspect the leak detection pump connector and wiring for damage, corrosion, or loose connections.
Step 3: Test the pump's electrical circuit with a multimeter for continuity and voltage (typically 12V at the pump connector with key on).
Step 4: If circuit is open, trace wiring back to the PCM and repair as needed; if circuit is intact, replace the leak detection pump.
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 Check Engine Light will remain on and the vehicle may fail an emissions test. The EVAP system does not affect engine performance or safety.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on whether the issue is a simple wiring fix or requires replacing the leak detection pump.