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P251D

PTO Engine Shutdown Circuit/Open

The PTO engine-shutdown command line is open. This safety input lets a connected work attachment (or operator switch) request an immediate engine shutdown — for example when an interlock is opened on a stationary aerial work platform. With the line broken, the safety shutdown cannot be commanded.

  • Check engine light: Yes
  • Emissions related: No
  • Repair difficulty: medium

Common causes

Ordered by how often each turns out to be the cause.

  • Broken shutdown wire or unplugged work attachmentCommon
  • Pin pushed back out of connector bodyLess likely
  • Cracked solder joint inside the module or sensorLess likely

Parts involved

  • Pto Shutdown Circuit
  • Wiring Harness

P251D is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.