P25A0Turbocharger B 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
- P25A0 says the regulator of turbocharger B has run to its low limit without reaching the boost target, so the second charger delivers too little pressure even with full control authority. It only exists on engines where two chargers are regulated separately. No manufacturer documents P25A0 publicly. CARB 13 CCR 1968.2 requires a fault once boost feedback control has used all of its adjustment and still misses the target, which describes this case. For the A side, Ford flags the same situation as P259E when requested boost exceeds measured boost by 120 kPa on its 6.7 L diesel for about 10 s. Leaks between charger B and the intake, a sticking wastegate or vanes and sensor errors are the usual suspects. P25A1 is the high-limit partner, P259E the turbocharger A version.
- What you may notice
- Engine warning lamp on
- Lower power than usual, uneven pull
- Likely causes
- LikelyLeak in the charge air path served by charger B
- PossibleWastegate or vanes of charger B not closing as commanded
- RareWorn or damaged charger B
- 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 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.