P255BPTO Speed Selector Sensor/Switch 2 Range/Performance
- Generic OBD-II code · Powertrain
- How the car detects it
- P255B flags an implausible reading from PTO speed selector 2 although its circuit is electrically intact. Because a second selector normally works together with the first, the check can compare both: requests that cannot coexist, a level that sits between valid positions, or a selection that the configured number of presets does not allow. On Ram chassis cabs from 2012 the Cummins controller can be set to between one and five remote PTO speeds, so a selector reporting a step beyond the programmed count would be a candidate for such a fault. CARB calls this a rationality diagnostic. No manufacturer documents P255B publicly. Suspects are a sticky switch, an upfitter wiring mistake that ties both inputs together, or a configuration that does not match the hardware.
- What you may notice
- Second preset ignored or wrong speed reached
- PTO speed control falls back to standby
- Likely causes
- LikelySticking selector 2 switch
- PossibleUpfitter wiring ties selector 1 and 2 together
- RareNumber of programmed presets does not match the switch
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.