P25A0 code meaning
Turbocharger B Boost Control Position At Low Limit
Powertrain system Generic code P25xx codes Check engine light
What P25A0 means
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.
P25A0 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 6 hours
- Clears after repairAfter a drive cycle
Symptoms of P25A0
- Engine warning lamp on
- Lower power than usual, uneven pull
Common causes of P25A0
- Most likelyLeak in the charge air path served by charger B
- PossibleWastegate or vanes of charger B not closing as commanded
- Less likelyWorn or damaged charger B
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Turbo actuator b
What each part of P25A0 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| A0 | The exact fault in that area. |
What to do next
- Note P25A0 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P25A0
What does P25A0 mean?
P25A0 means "Turbocharger B Boost Control Position At Low Limit". 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 is a generic code, so it means the same on every make.
Is it safe to drive with P25A0?
Drive gently and only to a workshop. With P25A0 the car can go into limp mode (reduced power) to protect itself.
Will P25A0 fail an emissions test?
Yes, it can. P25A0 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P25A0 to fix?
Difficulty: medium. A typical repair takes 0.5 to 6 hours of work. This is a job for a workshop.
Will P25A0 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.