P2406 Fault Code

Evaporative Emission System Leak Detection Pump Sense Circuit High

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2406 fault code indicates a problem with the Evaporative Emission System Leak Detection Pump Sense Circuit, specifically that there is a high reading in the circuit. This system is designed to prevent fuel vapors from escaping into the atmosphere, ensuring the vehicle operates efficiently and in compliance with environmental regulations.

• The leak detection pump is critical for checking the integrity of the EVAP system.
• A high voltage signal sent from the pump's sense circuit could suggest a failure in the pump or other components within the circuit.
• Proper functioning is essential for optimizing engine performance and reducing emissions.

What are the symptoms of the P2406 code?

Common symptoms associated with a P2406 fault code include:

• Illuminated check engine light on the dashboard.
• Decreased fuel efficiency due to improper EVAP functioning.
• Potential rough idling or stalling in some vehicles.
• Notices of failing emissions tests during inspection.

What causes the P2406 code?

Several factors may contribute to a P2406 code, including:

• A defective leak detection pump.
• Damaged or corroded wiring in the sense circuit.
• Poor connections at the pump or ECU.
• Faulty engine control unit (ECU) settings.
• Other related components in the EVAP system that have failed.

How to fix P2406?

To resolve a P2406 error code, the following steps can be taken:

• Begin with a thorough inspection of the leak detection pump and its wiring for any visible damage.
• Test the functionality of the leak detection pump to ensure it operates as intended.
• Check electrical connections and repair or replace any corroded components.
• If issues persist, perform a full diagnostic to determine if the ECU is sending incorrect signals or if another component is at fault.
• Clear the code from the ECU after repairs and test drive the vehicle to ensure the problem has been resolved.