OBD-II code · Powertrain (generic, extended)
P251C PTO Enable Switch Circuit High
The PTO enable switch input reads stuck high — typically a short to battery voltage. The ECM cannot pull the input low, so the switch state is unreadable and PTO mode is locked out for safety.
Is it safe to drive with P251C?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySwitch wire shorted to battery voltage
- Less likelyConnector pins corroded - high contact resistance
- Less likelySupply wire pinched against B+ source
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Pto Enable Switch, Wiring Harness
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.