P0048 Fault Code

P0048 OBD-II Trouble Code Short Description

Turbocharger/Supercharger Boost Control "A" Circuit High

What does trouble code P0048 mean?

The P0048 fault code on cars refers to an issue with the Turbocharger/Supercharger Boost Control "A" Circuit. This code indicates that the boost control system is detecting a high voltage or resistance within the circuit.

When the turbocharger or supercharger is operating, it relies on the boost control system to regulate the amount of air pressure entering the engine. This helps improve performance and power output. However, if the boost control circuit is experiencing high voltage or resistance, it can lead to various problems.

One possible cause of this fault code is a faulty boost pressure sensor. This sensor is responsible for monitoring the amount of boost pressure and relaying the information to the engine control module (ECM). If the sensor is malfunctioning or sending incorrect signals, the ECM may interpret it as a high voltage or resistance issue.

Another potential cause is a problem with the wiring or connectors associated with the boost control circuit. Damaged or corroded wires, loose connections, or faulty connectors can disrupt the flow of electricity and lead to high voltage or resistance readings.

To diagnose and fix the P0048 fault code, it is recommended to follow these steps:

  1. Perform a visual inspection of the wiring and connectors associated with the boost control circuit. Check for any visible damage, loose connections, or corroded components. Repair or replace as necessary.

  2. Test the boost pressure sensor using a multimeter to measure the voltage output. Compare the readings to the manufacturer's specifications. If the readings are out of range, replace the sensor.

  3. Clear the fault codes using a diagnostic scanner and test drive the vehicle to see if the code returns. If it does not, the issue may have been resolved. If the code reappears, further diagnosis may be needed.

  4. If the above steps do not solve the problem, it is recommended to seek professional help from a certified mechanic or dealership. They have the necessary tools and expertise to diagnose and repair complex electrical issues.

It is important to address the P0048 fault code promptly, as it can affect the performance and fuel efficiency of the vehicle. Ignoring this code may result in engine power loss, reduced acceleration, and potential damage to the turbocharger or supercharger system.

Always consult the vehicle's specific repair manual or contact a professional for accurate diagnosis and appropriate solutions.


What are the symptoms of the P0048 code?

When encountering the P0048 fault code, the following symptoms may be observed in cars:

  • Check Engine Light (CEL) illuminated on the dashboard.
  • Decreased engine performance or lack of power under acceleration.
  • Turbocharger or supercharger may not engage or provide sufficient boost.
  • Hesitation or a delay in throttle response.
  • Poor fuel economy.
  • Possible engine misfires or rough idling.

It is important to note that the symptoms may vary depending on the specific vehicle make and model.


What causes the P0048 code?

The P0048 fault code refers to the Turbocharger/Supercharger Boost Control "A" Circuit being too high. This code typically indicates a problem with the boost control solenoid or a related electrical circuit. Here are some possible causes of this fault code:

  • Faulty boost control solenoid: The boost control solenoid may be malfunctioning, not allowing for proper control of the turbocharger or supercharger boost pressure.

  • Wiring or connection issues: There may be an issue with the wiring harness or electrical connections related to the boost control solenoid. This can cause a high resistance or an open circuit, resulting in the P0048 code being triggered.

  • Blocked or leaking vacuum lines: Vacuum lines that are blocked or leaking could prevent proper boost control, causing a high boost pressure and triggering the fault code.

  • Faulty pressure sensors: If the pressure sensors that monitor the boost pressure are faulty, they may send incorrect signals to the engine control module (ECM), resulting in the P0048 code.

  • ECM malfunction: In some cases, the fault code may be caused by an issue with the ECM itself. This could be due to a software glitch or a hardware problem.

If you encounter the P0048 fault code in your vehicle, it is recommended to have it diagnosed and repaired by a qualified mechanic. They will be able to perform proper troubleshooting procedures to determine the exact cause of the code and perform the necessary repairs.

Possible Solutions

How to fix P0048?

To fix the P0048 fault code on cars, follow these steps:

  1. Check the wiring: Start by inspecting the wiring connected to the turbocharger or supercharger boost control sensor. Look for any damaged wires, loose connections, or corrosion. Repair or replace any faulty wiring.

  2. Check the boost control solenoid: Locate the boost control solenoid, usually found near the turbocharger or supercharger. Check the solenoid's electrical connection and make sure it is secured properly. If the solenoid is faulty, replace it.

  3. Inspect the boost pressure sensor: Check the boost pressure sensor for any signs of damage or corrosion. Clean the sensor if necessary. If the sensor is defective, replace it.

  4. Check the vacuum lines: Inspect the vacuum lines connected to the boost control system. Look for any cracks, leaks, or loose connections. Repair or replace any faulty vacuum lines.

  5. Test the boost control system: Use a diagnostic scanner to perform a boost control system test. This will help identify any underlying issues causing the high circuit voltage. Follow the scanner's instructions and repair any problems detected.

  6. Clear the fault code: After fixing the issue, use the diagnostic scanner to clear the fault code from the car's computer. This will reset the system and turn off the check engine light.

Please note that these are general troubleshooting steps, and it is advised to refer to the specific repair manual for your car model for detailed instructions.