P2451 OBD-II: Evaporative Emission System Switching Valve Stuck Closed

P2451 Severity

Moderate

Will P2451 go away on its own?

Once the vehicle's onboard system no longer detects the issue, most codes will disappear on their own. If your vehicle still has this code, however, it should be properly diagnosed to avoid a more serious problem.

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Moderate severity codes might not threaten the vehicle's safety or functionality immediately, but you should still get it diagnosed within a reasonable time frame to keep your car running well.

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What causes OBD-II fault code P2451?

The Leak Detection Pump is part of the Evaporative Emissions System. After the vehicle has been sitting for a few hours, this pump will turn on and create a vacuum in the EVAP system. The engine computer (PCM) runs this test when the vehicle is off. If the PCM does not see the Leak Detection Pump activate as requested, or does not see a vacuum created in the EVAP System, the PCM will set code P2451.

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OBD II Fault Code

  • OBD II P2451

OBD-II Code Powertrain Control Module (PCM) failure is defined as a Evaporative Emission System Switching Valve Stuck Closed

The Leak Detection Pump is part of the Evaporative Emissions System. After the vehicle has been sitting for a few hours, this pump will turn on and create a vacuum in the EVAP system. The engine computer (PCM) runs this test when the vehicle is off. If the PCM does not see the Leak Detection Pump activate as requested, or does not see a vacuum created in the EVAP System, the PCM will set code P2451.

Common Problems That Trigger the P2451 Code

  • Evap leak detection pump failure
  • Powertrain Control Module (PCM) failure
  • Wiring issue
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