P255BPowertrain · Speed, idle & cruiseGeneric (SAE) code

P255B: PTO Speed Selector Sensor/Switch 2 Range/Performance

PTO speed selector switch 2 is electrically intact but its value does not match a valid bit pattern — multiple positions asserted, or values that do not map to any preset.

Typical labor cost
$40–$190 est.
18 min–1.5 h at an assumed $125/hr · parts extra · use your rate
Most common fix
Contaminated rotary contact
DIY difficulty: Moderate · DIY-friendly
01 —What it means

What P255B means

P255B is a generic OBD-II powertrain code in the speed, idle & cruise group. In plain English: the signal is within electrical limits but doesn’t make sense compared with other readings, so the part or system isn’t performing as expected.

P
Powertrain
2
Generic (SAE)
5
Subsystem group
5B
Specific fault
How to read P255B. We group it under Speed, idle & cruise.
Check engine light
Usually on
Emissions-related
No
Limp mode possible
Not typical
Drive cycle to clear
Not required
Code data: OBDex (CC0)

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02 —Causes

Common causes

Ranked from most to least likely
  1. 01Contaminated rotary contactMost likely
  2. 02Sensor element aged beyond calibration windowLess likely
  3. 03Sensor mounting loose - signal dampingLess likely
Code data: OBDex (CC0)
03 —Severity

Can I drive with P255B?

Moderate

Usually yes, for a short time.

The car will often drive normally, but get it diagnosed soon. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.

Why we rate it moderate

  • Turns on the check engine light

Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.

Code data: OBDex (CC0)
04 —Diagnosis

How to diagnose P255B

General procedure — follow the service manual for your vehicle
  1. 1

    Confirm the code and save freeze-frame data

    Read the codes with an OBD-II scan tool and note every code, not just P255B. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.

  2. 2

    Check for related codes first

    Look for P255A. Related codes often share a cause; a circuit or sensor code usually needs fixing before a performance code like this one.

  3. 3

    Check live data

    Watch the related sensor and actuator readings in live data (Pto speed selector 2) and compare them with expected values in the service information for your vehicle.

  4. 4

    Test the likely causes in order

    Start with the most likely cause and work down: Contaminated rotary contact; sensor element aged beyond calibration window; sensor mounting loose - signal damping. Test before replacing parts.

  5. 5

    Check for recalls and service bulletins

    Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.

  6. 6

    Clear the code and verify the repair

    After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.

Code data: OBDex (CC0)
05 —Cost

P255B repair cost estimate

Labor only — set your local shop rate
Labor estimate for P255B
$40–$190
18 min–1.5 h of labor × $125/hr (assumed rate) · parts extra

Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.

DIY difficulty
Moderate
Good DIY job?
Yes, with a scan tool

Needs a scan tool and some experience with testing.

Code data: OBDex (CC0)
06 —Components

Parts and systems involved

  • Pto speed selector 2
Code data: OBDex (CC0)
08 —FAQ

P255B FAQ

What does P255B mean?

P255B means “PTO Speed Selector Sensor/Switch 2 Range/Performance”. PTO speed selector switch 2 is electrically intact but its value does not match a valid bit pattern — multiple positions asserted, or values that do not map to any preset.

Is P255B serious? Can I keep driving?

We rate P255B as moderate severity. Usually yes, for a short time. The car will often drive normally, but get it diagnosed soon. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.

What causes P255B?

The most common causes, from most to least likely: Contaminated rotary contact; Sensor element aged beyond calibration window; Sensor mounting loose - signal damping. Test before replacing parts, because several causes can set the same code.

How much does it cost to fix P255B?

Typical labor is about $40–$190 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.

Can I fix P255B myself?

DIY difficulty is moderate. Many owners can handle it with a scan tool, a multimeter and basic hand tools. Always confirm the cause before buying parts.

Will P255B clear itself?

If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.

Code data: OBDex (CC0)