P2406 low

Evaporative Emission System Leak Detection Pump Sense Circuit High

The P2406 code means the vehicle's onboard diagnostic system has detected: Evaporative Emission System Leak Detection Pump Sense Circuit High. This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
moderate
Estimated cost
$100 - $400 (parts and labor)
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Common Symptoms

  • Check Engine Light illuminated
  • Failed emissions inspection
  • No effect on vehicle performance
  • EVAP readiness monitor incomplete
  • Fuel vapor smell near vehicle possible

Probable Causes (Ranked by Likelihood)

  • Open sense wire in leak detection pump circuit Very High
  • Failed pressure sensor in pump (reading high) High
  • Disconnected pump sense connector Moderate
  • ECM sense input pulled high due to open circuit Moderate

Step-by-Step Diagnostic Procedure

  1. Check pump connector for disconnected or damaged sense wire pin

  2. Measure sense circuit voltage at the ECM connector

  3. Inspect wiring for open circuits between pump and ECM

  4. Test pump sensor with scan tool live data

  5. Check for recent undercarriage work that may have disturbed wiring

Frequently Asked Questions

Can I drive with code P2406?

Yes, safe to drive with no impact on vehicle operation. Only emissions testing is affected.

What causes P2406?

Usually an open circuit in the pump sense wiring or a disconnected connector. Check the connector first for a quick fix.

Is P2406 expensive to fix?

Typically $100 to $400. A disconnected connector costs nothing to fix. Pump assembly replacement is the most expensive option.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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