P056F code meaning
Cold Start Turbocharger/Supercharger Boost Control B Performance
Powertrain system Generic code P05xx codes Check engine light
What P056F means
CARB requires every element commanded by the cold-start strategy to respond measurably in the commanded direction, with its own codes separate from the general monitoring of the same part. During catalyst heating the boost control is positioned deliberately – diesels close the variable turbine for load and heat, gasoline engines open the wastegate so heat reaches the catalyst. P056F is the same check for boost control B – a second charger on twin-turbo or sequential systems, or a second stage. No manufacturer document available to us uses P056F; the Ram 6.7 L with a single charger only lists P056E. The description follows CARB's cold-start rules.
P056F at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P056F
- Check engine light on
- Rough cold running
- Otherwise usually unremarkable
Common causes of P056F
- Most likelyCharger B actuator stiff or faulty
- PossibleVacuum or charge air line of charger B leaking
- PossibleSoftware or calibration
- Less likelyBoost or position sensor B
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Turbocharger actuator bBoost pressure sensorEngine control module
What each part of P056F means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 6F | The exact fault in that area. |
What to do next
- Note P056F 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 P056F
What does P056F mean?
P056F means "Cold Start Turbocharger/Supercharger Boost Control B Performance". CARB requires every element commanded by the cold-start strategy to respond measurably in the commanded direction, with its own codes separate from the general monitoring of the same part. It is a generic code, so it means the same on every make.
Is it safe to drive with P056F?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P056F fail an emissions test?
Yes, it can. P056F 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 P056F to fix?
Difficulty: hard. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P056F 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.