Fix P2403: STEP-BY-STEP diagnostic GUIDE!

The P2403: Evaporative Emission System Leak Detection Pump Sense Circuit/Open refers to an issue where the sense circuit for the leak detection pump in the evaporative emission system is either open or not functioning correctly. This can lead to problems such as increased emissions, potential failure to pass emissions tests, and inefficiencies in the vehicle’s emission control system.

P2403 – Quick Overview

Code	Information
Meaning	P2403: Evaporative Emission System Leak Detection Pump Sense Circuit/Open
Is it serious?	Yes, this code can lead to increased emissions and may cause the vehicle to fail an emissions test.
Possible causes	– Open circuit in the leak detection pump sense circuit – Faulty leak detection pump – Wiring or connector issues
How to diagnose?	– Inspect and test the leak detection pump sense circuit – Check wiring and connectors – Replace faulty leak detection pump if necessary

P2403 Meaning

The P2403: Evaporative Emission System Leak Detection Pump Sense Circuit/Open code indicates that there is an issue with the sense circuit of the leak detection pump within the vehicle’s evaporative emission system. The leak detection pump is responsible for pressurizing the system to identify any leaks that could allow fuel vapors to escape into the atmosphere. An open or malfunctioning sense circuit can prevent the system from accurately detecting leaks, leading to increased emissions and potential environmental harm.

Step-by-step diagnostic guide

Action	Description	Tools Needed
Check for Other Codes	Use an OBD-II scanner to identify any additional related codes that might provide more context to the issue. Additional codes can help pinpoint the exact cause.	OBD-II Scanner
Inspect the Leak Detection Pump Sense Circuit	Visually inspect the sense circuit wiring and connections for any signs of damage, wear, or disconnections. Ensure all connections are secure and free from corrosion.	Flashlight, Visual Inspection Tools
Test the Leak Detection Pump Sense Circuit	Use a multimeter to check for continuity and proper voltage in the sense circuit. Compare the readings to the manufacturer’s specifications to determine if there is an open circuit.	Multimeter, Wiring Diagram
Inspect and Test the Leak Detection Pump	Locate the leak detection pump and inspect it for any physical damage or signs of malfunction. Use a diagnostic tool to activate the pump and observe its operation. Replace the pump if it does not function correctly.	Multimeter, Diagnostic Tool, Replacement Leak Detection Pump
Check Wiring and Connectors	Examine all wiring and connectors associated with the leak detection pump sense circuit for any signs of fraying, corrosion, or breaks. Repair or replace any faulty wiring or connectors as necessary to restore proper circuit functionality.	Multimeter, Wire Repair Tools, Connector Cleaning Tools
Inspect and Repair Wiring Issues	Trace the wiring from the control module to the leak detection pump, looking for any breaks, shorts, or areas where the wiring may have been damaged. Repair or replace any faulty sections of wiring to ensure a complete and functional circuit.	Wiring Repair Tools, Multimeter
Clear the Code and Test Drive	After performing the necessary repairs, clear the P2403 code using an OBD-II scanner. Take the vehicle for a test drive to ensure that the issue has been resolved and the code does not reappear.	OBD-II Scanner, Vehicle Owner’s Manual
Recheck for Codes	After the test drive, use the OBD-II scanner again to verify that the P2403 code has been cleared. If the code returns, further diagnosis may be required to identify and fix underlying issues.	OBD-II Scanner