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.
Medium severity. Can I keep driving?If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
Symptoms
- Second preset unavailable
- PTO switched off by the controller
Most likely causes
- Selector 2 wire chafed against a battery-fed circuit
- Upfitter applies 12 V to a ground-switched input
- Lost ground or return line of selector 2
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of P255D means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 5: Speed and idle
- 5D: Specific fault in that system
Frequently asked questions
Can I keep driving with code P255D?
If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
What causes code P255D?
The most common causes are: selector 2 wire chafed against a battery-fed circuit; upfitter applies 12 V to a ground-switched input; lost ground or return line of selector 2.
Related codes
- P255APTO Speed Selector Sensor/Switch 2 Circuit/Open
- P255BPTO Speed Selector Sensor/Switch 2 Range/Performance
- P255CPTO Speed Selector Sensor/Switch 2 Circuit Low
- P255EPTO Speed Selector Sensor/Switch 2 Circuit Intermittent/Erratic
- P254DPTO Speed Selector Sensor/Switch 1 Circuit High
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.