P0234critical severityPowertrain
Turbocharger/Supercharger A Overboost Condition
on 2011 Subaru Legacy 3.6L H6 · AWD
What this code means
The boost pressure has exceeded the maximum allowed value.
Symptoms
- Check Engine Light
- Excessive power then limp mode
- Whining turbo noise
- Possible engine damage
Common causes
- Wastegate stuck closed
- Boost control solenoid failure
- Boost pressure sensor fault
- Blocked wastegate actuator hose
Diagnostic steps
- Check wastegate operation
- Test boost control solenoid
- Monitor boost pressure
- Inspect vacuum lines to wastegate
Repair notes
Address immediately to prevent engine damage. Check wastegate and boost control.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1