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DTC codes / P00xx · Fuel and air metering and auxiliary emission controls / P0048

P0048Turbo/Super Charger Boost Control Solenoid Circuit High

P0048 indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the control circuit for the turbocharger or supercharger boost control solenoid. This typically means the solenoid circuit is shorted to voltage, the solenoid itself has failed, or the wiring is damaged, preventing the PCM from properly regulating boost pressure.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaFuel and air metering and auxiliary emission controls

Symptoms you may notice

  • Illumination of the check engine light, often with no other noticeable symptoms
  • Reduced engine performance or a lack of boost, leading to sluggish acceleration
  • The engine may enter limp mode, limiting power for protection
  • Poor fuel economy due to incorrect boost control
  • In some cases, the turbocharger may produce excessive boost, causing overboost codes or engine damage
  • Audible clicking or unusual noises from the boost control solenoid area

Common causes, most likely first

  1. Faulty boost control solenoid (internally shorted or open coil)
  2. Short to voltage in the control circuit wiring (e.g., chafed wire contacting a power source)
  3. Corroded or damaged electrical connector at the solenoid or PCM
  4. Failed PCM driver for the boost control solenoid (rare but possible)
  5. Aftermarket or improperly installed electronic boost controller interfering with the circuit
  6. Moisture intrusion into the solenoid or connector causing high resistance or short

How to diagnose and fix it

  1. Verify the code with a scan tool and check for any related codes (e.g., P0045, P0046, P0047) to confirm the circuit fault.
  2. Inspect the boost control solenoid connector and wiring for signs of corrosion, damage, or loose pins; repair as needed.
  3. Disconnect the solenoid and measure resistance across its terminals; compare to manufacturer specifications (typically 10-30 ohms). Replace if out of range.
  4. With the solenoid disconnected and ignition on, measure voltage on the control circuit from the PCM; it should be near zero volts. If battery voltage is present, trace the wire for a short to voltage.
  5. Check the ground circuit for the solenoid if applicable; ensure clean, tight connections and proper continuity to ground.
  6. If wiring and solenoid test good, suspect the PCM; perform a wiggle test and check for intermittent faults before replacing the PCM.
  7. Clear codes and test-drive the vehicle to verify the repair and ensure the code does not return.

Common Misdiagnosis Traps for P0048

  • A shorted boost control solenoid is often replaced unnecessarily when the real issue is a chafed wire harness rubbing against a metal bracket near the turbocharger.
  • The PCM may set P0048 if the solenoid circuit is open, not just shorted high, because some drivers interpret an open circuit as a high voltage condition; always check resistance and voltage drops.
  • Aftermarket piggyback tuners or boost controllers that tap into the solenoid wiring can cause this code by feeding voltage back into the circuit, even if the factory solenoid is healthy.
  • Corrosion inside the solenoid connector can create a high-resistance path that mimics a short to voltage, so always inspect the connector terminals under magnification.
  • On some vehicles, a failing turbocharger vane position sensor or wastegate actuator can cause the PCM to command abnormal solenoid duty cycles, indirectly setting P0048; check for related boost control codes.

Can I keep driving with P0048?

It is generally safe to drive with P0048 as long as the vehicle is not in limp mode and you avoid aggressive acceleration or heavy towing, but prolonged driving with a boost control fault can lead to poor performance and potential turbocharger damage. Have the fault diagnosed promptly to prevent secondary issues.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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