P0049: Turbocharger/Supercharger A Turbine Overspeed — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
Turbocharger/Supercharger A Turbine Overspeed. Basic catalogue definition; diagnostic details have not yet been reviewed.
Affected system: Powertrain
Symptoms
- Check Engine Light illumination
- Noticeable loss of engine power
- Limp mode activation
- Excessive turbocharger noise
- Engine hesitation under acceleration
Possible causes
- Faulty turbocharger wastegate actuator
- Damaged or leaking vacuum lines
- Stuck or jammed turbocharger turbine blades
- Faulty boost pressure control solenoid
- Exhaust leaks upstream of the turbocharger
- PCM software error or internal failure
What to check
- Inspect all vacuum and boost hoses for cracks or leaks
- Verify the mechanical movement of the wastegate linkage for binding
- Test the boost pressure control solenoid for electrical continuity
- Check the turbocharger turbine for physical damage or debris obstruction
- Perform a road test while monitoring live boost pressure data with a scanner
Also written as: P0049-00, P004900, PO049 (some scan tools add the fault-type byte, e.g. -00).