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DTC codes / P25xx · Vehicle speed, idle control and auxiliary inputs / P251F

P251FPTO Engine Shutdown Circuit High

P251F indicates that the Powertrain Control Module (PCM) has detected an abnormally high voltage on the Power Take-Off (PTO) engine shutdown circuit, which is used to remotely kill engine power for auxiliary equipment operation. The PCM expects a specific voltage range on this circuit, and a reading above the threshold triggers the code, often disabling the PTO function or preventing engine start.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaVehicle speed, idle control and auxiliary inputs

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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