What it means
The control module detects an intermittent or erratic signal in the EVAP leak detection pump sense circuit. This is an electrical feedback fault and does not, by itself, indicate a vapor leak.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The EVAP leak detection pump moves air through the fuel-vapor system so the control module can check for leaks. The module monitors the pump’s sense feedback and sets P2407 when that signal changes unpredictably or drops in and out. This points to an intermittent electrical or feedback problem, not necessarily a vapor leak.
Common causes
Most likely first.
- Pump diaphragm worn
- Sense wiring high resistance
- Sensor element aged beyond calibration window
Symptoms
- Check engine light on
How to diagnose it
- Record freeze-frame data and check pump-sense live data during an EVAP test to see when the signal becomes erratic.
- Inspect the leak detection pump, its diaphragm area, connector, and nearby wiring for damage, moisture, or loose contacts.
- Check the sense-circuit terminals for corrosion, poor pin fit, or a pushed-back pin that could interrupt feedback.
- With the circuit isolated as specified by the manufacturer, check sense-wire continuity and resistance while gently moving the harness.
- If the wiring checks out, test the pump diaphragm and sense element against the manufacturer's specification.
Common fixes
- Repair a loose or corroded pump-sense connector.
- Repair high-resistance or damaged sense wiring.
- Replace a worn leak detection pump diaphragm or pump assembly.
- Replace an aged sense element if it fails the manufacturer's test.
Can I keep driving?
The only listed symptom is the check-engine light, and this code does not by itself show a vapor leak or an immediate drivability problem. You can generally drive gently, but arrange diagnosis because an unresolved EVAP fault can prevent the vehicle from monitoring fuel-vapor emissions.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.