P2405EVAP System

Evaporative Emission System Leak Detection Pump Sense Circuit Low

The control module has detected a low voltage on the leak detection pump sense circuit. This usually indicates a short to ground in the sense wiring or a fault inside the pump sensing element.

🚗 Yes, driving is safe. It is an emissions fault with no effect on performance, but it should be repaired for emissions compliance.

LOW

severity

🎯 Top Causes, Ranked by Likelihood

#1Short to ground in sense wiring$80-$250

35%

A damaged sense wire contacts ground and pulls the reading low.

#2Faulty leak detection pump$120-$300

35%

The internal sensing element in the pump has failed low.

#3Corroded connector$40-$150

20%

Moisture in the pump connector shorts or degrades the sense signal.

#4PCM sense input fault$200-$600

10%

The control module input for the sense circuit has failed internally.

🩺 Common Symptoms

Check engine light is on
EVAP readiness monitor does not complete
No drivability change
Possible failed emissions test

💰 Repair Cost: DIY vs Shop

DIY Cost

$120-$300

Shop Cost

$200-$450

📋 Free OBD2 Code Cheat Sheet

The 50 most common codes with likely cause and DIY fix cost. Sent once, no spam.

🔧 How to Diagnose P2405

1Inspect the pump connector and sense wiring for damage, chafing, or corrosion.

2Check the sense circuit for a short to ground with the connector unplugged.

3Measure the pump sense element resistance and compare to spec.

4Replace the pump if internal sensing is faulty, then clear and retest.

❓ Frequently Asked Questions

What does a low sense circuit mean?

The signal voltage is below the expected range, usually from a short to ground or a failed sensing element inside the pump.

Is it safe to drive?

Yes. It affects emissions monitoring only and has no impact on how the car drives.

Can I test this myself?

With a multimeter you can check the sense wiring for a short to ground and measure the pump resistance.

🔗 Related Codes

P2401P2402P2404P0455P0442