Powertrain, generic (extended)

P255D PTO Speed Selector Sensor/Switch 2 Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

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.

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

Symptoms

  • Second preset unavailable
  • PTO switched off by the controller

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–300
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

pto speed selector 2

Related codes

P255AP255BP255CP255EP254D

References: law.cornell.edu, http:, gmupfitter.com.