P2406EVAP System

Evaporative Emission System Leak Detection Pump Sense Circuit High

The control module has detected a high voltage on the leak detection pump sense circuit. This usually indicates an open circuit or a short to power in the sense wiring, or a failed pump sensing element.

🚗 Yes. This is an emissions fault that does not affect drivability, but it should be repaired to pass emissions testing.

LOW

severity

🎯 Top Causes, Ranked by Likelihood

#1Open in sense wiring$80-$250

35%

A broken sense wire leaves the circuit open and reading high voltage.

#2Faulty leak detection pump$120-$300

30%

The internal sensing element has failed high.

#3Short to voltage$80-$250

20%

The sense wire contacts a power source, pulling the reading high.

#4Corroded connector$40-$150

15%

High resistance at the connector produces a high sense reading.

🩺 Common Symptoms

Check engine light is on
EVAP 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 P2406

1Inspect the pump connector and sense wiring for opens and corrosion.

2Check the sense circuit for continuity and for a short to power.

3Measure the pump sense element resistance against specification.

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

❓ Frequently Asked Questions

What causes a high sense circuit code?

Usually an open circuit or a short to power in the sense wiring, or a failed sensing element inside the pump.

Is driving safe?

Yes. It affects emissions monitoring only and does not change how the car drives.

Is this usually wiring or the pump?

Wiring and connector faults are common first suspects before the pump itself.

🔗 Related Codes

P2401P2402P2404P2405P0455