P251DPTO Engine Shutdown Circuit/Open
- Generic OBD-II code · Powertrain
- How the car detects it
- P251D covers the engine shutdown line of a power take-off installation. On trucks with body equipment such as cranes, pumps or aerial devices, a hard-wired signal lets the PTO controller or an equipment stop button tell the engine module to switch the engine off. P251D means the module cannot read a valid state on that line, usually because the wire or plug is open. No manufacturer documents P251D publicly or states how the engine reacts; the description rests on CARB's PTO definition and on GM's PTO bulletin PIP6108, which shows how ground and harness faults upset PTO circuits. Depending on calibration the PTO may be locked out, or a stop request from the equipment may no longer reach the engine. P251E and P251F name a fixed low or high level.
- What you may notice
- PTO locked out or equipment will not run
- Equipment stop button no longer shuts down the engine
- Likely causes
- LikelyOpen shutdown wire or loose connector at the body interface
- PossibleFault in the body equipment's stop switch or controller output
- RareShutdown input enabled in calibration but not wired by the upfitter
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.