P259ETurbocharger A Boost Control Position At Low Limit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P259E means the boost control of turbocharger A has run out of range at the low end: the actuator is at its limit, yet boost stays well under the target. Ford's 2023 diesel OBD summary places it in the underboost monitor. With closed-loop boost control active, at least 50 Nm (6.7 L) or 135 Nm (3.0 L) and 800 or 1300 rpm, it sets when desired boost exceeds actual boost by more than 120 kPa (6.7 L) or 80 kPa (3.0 L) for roughly 10-11 s. Ford's special service message 50564 for 2020-2022 Super Duty 6.7 L lists P259E among turbo-related codes and makes the variable vane actuator available on its own, so the whole turbocharger need not be replaced. P259F is the opposite limit, P2263 the slower general boost performance check, P0299 plain underboost.
- What you may notice
- Engine warning lamp on
- Clear loss of power under load
- Whistling or hissing from the charge air side
- Likely causes
- LikelyLeak in charge air pipes, intercooler or clamps
- PossibleVariable vane actuator or vane mechanism not reaching the commanded position
- PossibleExhaust leak upstream of the turbine
- RareBoost pressure sensor reading too low
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €2,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.