P003A OBD II Trouble Code Turbocharger/Supercharger Boost Control A Position Exceeded Learning Limit

How to quickly diagnose, repair, and info on symptoms and causes of a P003A code that indicates the turbo or supercharger A boost control has exceeded its learning limit.

Symptoms of P003A OBD II Trouble Code

  • Low, erratic and/or abnormal power levels
  • Overall poor drivability
  • Decrease in throttle response
  • Trouble driving up hills
  • Vehicle enters "limp" mode (i.e. fail-safe)
  • Intermittent driveability symptoms

Common Causes of P003A OBD II Trouble Code

  • Defective or damaged boost control solenoid (e.g. lever stuck, broken, bent, etc.)
  • Corrosion causing high resistance (E.G: Connectors, pins, grounds, etc.)
  • Wiring issue (e.g. Frayed, open, short to power, short to ground, etc.)
  • ECM (Engine Control Module) internal issue
  • Excessive exhaust soot in vanes of charger, causing stagnant high/low/incorrect boost levels
  • Boost control module issue
  • Exhaust leak

Severity of P003A OBD II Trouble Code

Severity is set to moderate-high. When there is a problem within the forced induction system, you risk altering the air/fuel ratio. Which, could, in my opinion will, cause significant engine damage if ignored or left unattended. Not only do you run the risk of damaging internal engine components but you will be getting terrible fuel mileage in the process, so it is in your best interest to repair any faults within the forced induction system.