P255D code meaning
PTO Speed Selector Sensor/Switch 2 Circuit High
What P255D means
P255D is stored when PTO speed selector 2 delivers a signal above the permitted maximum. A chafed wire touching a battery-fed circuit, a lost sensor ground, or an upfitter feeding 12 V into an input meant to be switched to ground are the realistic causes. Upfitter manuals show why the last point matters: Ram describes its VSIM preset inputs as switch-to-ground circuits, while GM's 2008–2014 remote set input interprets anything above 3.33 V as a speed request, so mixing up the conventions of different trucks produces readings outside the expected range. No manufacturer documents P255D publicly. P255C is the low-side code; P254D covers selector 1. The second preset may be unavailable or the PTO is shut off.
P255D at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P255D
- Second preset unavailable
- PTO switched off by the controller
Common causes of P255D
- Most likelySelector 2 wire chafed against a battery-fed circuit
- PossibleUpfitter applies 12 V to a ground-switched input
- Less likelyLost ground or return line of selector 2
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pto speed selector 2
What each part of P255D means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 5D | The exact fault in that area. |
What to do next
- Note P255D and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P255D
What does P255D mean?
P255D means "PTO Speed Selector Sensor/Switch 2 Circuit High". P255D is stored when PTO speed selector 2 delivers a signal above the permitted maximum. It is a generic code, so it means the same on every make.
Is it safe to drive with P255D?
P255D does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P255D fail an emissions test?
P255D is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P255D to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P255D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.