P004E Fault Code

P004E OBD-II Trouble Code Short Description

Turbocharger/Supercharger Boost Control A Circuit Intermittent/Erratic

What does trouble code P004E mean?

The P004E fault code refers to a problem with the turbocharger or supercharger boost control circuit in a car's engine. This code indicates that there is an intermittent or erratic issue with the boost control system.

The turbocharger or supercharger is responsible for increasing the amount of air going into the engine, which in turn increases power and performance. The boost control system regulates the amount of pressure generated by the turbocharger or supercharger to ensure optimal engine performance.

When the P004E code is triggered, it means that the boost control circuit is experiencing a malfunction. This could be due to a faulty boost control solenoid, a defective boost pressure sensor, a wiring issue, or a problem with the engine control module (ECM).

To diagnose and fix the P004E code, it is recommended to follow these steps:

  1. Scan the vehicle's computer system: Use a diagnostic scanner to retrieve the specific trouble code and any additional codes. This will provide more insight into the exact issue and help identify the appropriate solution.

  2. Inspect the boost control system: Check the boost control solenoid, boost pressure sensor, and their associated wiring for any visible signs of damage or corrosion. Also, ensure that all connections are secure.

  3. Test the boost control solenoid: Using a multimeter, test the resistance of the boost control solenoid to determine if it is working properly. Compare the readings to the manufacturer's specifications.

  4. Check the boost pressure sensor: Test the operation of the boost pressure sensor to ensure it is providing accurate readings. Again, refer to the manufacturer's specifications for the correct voltage values.

  5. Evaluate the wiring and connectors: Examine the wiring harnesses and connectors related to the boost control system for any damage, loose connections, or breaks. Repair or replace as necessary.

  6. Clear the fault code and test drive: After addressing any identified issues, clear the fault code from the vehicle's computer system. Take the car for a test drive to verify that the P004E code no longer returns.

If the problem persists after performing the above steps, it is advisable to seek assistance from a qualified mechanic or dealership technician. They will have the expertise and necessary tools to diagnose and repair the turbocharger or supercharger boost control system.

It is essential to address the P004E code promptly as a malfunctioning boost control system can lead to decreased engine performance, reduced fuel efficiency, and potential long-term damage to the engine.


What are the symptoms of the P004E code?

The P004E fault code indicates an intermittent or erratic issue with the Turbocharger/Supercharger Boost Control A Circuit. Common symptoms of this fault code may include:

  • Check Engine Light (CEL) or Malfunction Indicator Lamp (MIL) illuminated on the dashboard.
  • Reduced engine power or loss of power during acceleration.
  • Turbocharger or supercharger not functioning properly.
  • Poor fuel economy.
  • Hesitation or lack of response when pressing the accelerator.
  • Rough idle or stalling.

It is important to note that these symptoms may vary depending on the specific vehicle make and model. It is recommended to have the vehicle diagnosed and repaired by a qualified mechanic or dealership.


What causes the P004E code?

The P004E fault code refers to an intermittent or erratic turbocharger/supercharger boost control A circuit. This code typically appears in vehicles equipped with turbocharged or supercharged engines. The potential causes for this fault code include:

  1. Faulty boost control solenoid: A malfunctioning solenoid can disrupt the boost control system, leading to inconsistent or erratic boost pressure.

  2. Wiring or connector issues: Damaged or corroded wires, as well as loose or poor connections, can interfere with the proper functioning of the boost control circuit.

  3. Boost pressure sensor problems: A faulty pressure sensor can send incorrect signals to the engine control module (ECM), causing intermittent or erratic boost control issues.

  4. ECM malfunction: A malfunction within the ECM itself can result in incorrect boost control signals, triggering the P004E fault code.

  5. Mechanical issues: Problems within the turbocharger or supercharger system, such as worn-out components or leaks, can also affect boost control and lead to intermittent or erratic boost pressure.

It is important to note that these are general potential causes, and the specific underlying issue can vary depending on the make and model of the vehicle. Proper diagnosis with a diagnostic tool and inspection of the affected components is recommended to pinpoint the exact cause of the P004E fault code.

Possible Solutions

How to fix P004E?

To fix the P004E fault code on cars, follow these steps:

  1. Check for any loose or damaged wires or connectors in the turbocharger/supercharger boost control circuit.
  2. Inspect the hoses and vacuum lines connected to the turbocharger/supercharger for any leaks or blockages.
  3. Ensure that the turbocharger/supercharger actuator is functioning properly. Test it for proper operation and replace if necessary.
  4. Verify that the boost pressure sensor is working correctly. Clean or replace it if there are any signs of damage or malfunction.
  5. Check the intake system for any restrictions or clogs that may affect the boost control.
  6. If the above steps do not resolve the issue, it is recommended to consult a professional mechanic or authorized dealership for further diagnosis and repair.

Please note: The specific repair steps may vary depending on the make and model of your car. It is advisable to refer to the vehicle's service manual for accurate instructions.