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, petrol engines open the wastegate so heat reaches the catalyst. P056E means boost control A (the first or only charger) did not follow its cold-start target. Its only documented user is Stellantis: the 2025 Ram 3500 cab chassis with 6.7 L Cummins lists it among codes that can light the warning lamp, fixed by a PCM software update; customers noticed hard cold starts and raised cold idle. Ford and GM do not use it.
Medium severity. Can I keep driving?Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.
Symptoms
- Check engine light on
- Hard cold start or rough warm-up
- Otherwise usually unremarkable
Most likely causes
- Variable turbine or wastegate actuator stiff (coking, cold)
- Module software or calibration
- Vacuum or boost hose leaking
- Position or boost sensor faulty
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P056E means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 5: Speed and idle
- 6E: Specific fault in that system
Frequently asked questions
Can I keep driving with code P056E?
Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.
What causes code P056E?
The most common causes are: variable turbine or wastegate actuator stiff (coking, cold); module software or calibration; vacuum or boost hose leaking.
Related codes
- P056FCold Start Turbocharger/Supercharger Boost Control B Performance
- P0299Turbocharger/Supercharger A Underboost Condition
- P0234Turbocharger/Supercharger A Overboost Condition
- P2563Turbocharger Boost Control Position Sensor A Circuit Range/Performance
- P050ACold Start Idle Control System Performance
- P052ACold Start A Camshaft Position Timing Over-Advanced Bank 1
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.