P0238 Fault Code

P0238 OBD-II Trouble Code Short Description

Turbocharger/Supercharger Boost Sensor "A" Circuit High Input

What does trouble code P0238 mean?

The P0238 fault code indicates that the turbocharger or supercharger boost sensor "A" circuit is registering a high input. This means that the sensor is detecting pressure that is higher than the expected range.

The possible causes of this issue can be a faulty boost sensor, damaged sensor wiring, or a malfunctioning turbocharger or supercharger. It can also be caused by a malfunctioning PCM (powertrain control module).

To resolve this issue, the first step is to diagnose and repair any damaged wiring or connectors in the boost sensor circuit. If that does not solve the problem, the boost sensor should be tested and replaced if necessary. If the issue persists after these steps, then further diagnosis is required to identify and repair any other underlying issues.

It is important to address this fault code promptly, as it can lead to reduced engine performance and potential damage to the turbocharger or supercharger.

  • Generic: Turbocharger/Supercharger Boost Sensor "A" Circuit High Input
  • GM: Turbocharger Boost Sensor Circuit High Voltage
  • Dodge Chrysler: MAP Sensor Voltage Too High


What are the symptoms of the P0238 code?

Some possible symptoms of a P0238 fault code are:

  • Illumination of the check engine light
  • Decreased engine performance or acceleration
  • Engine stalling or hesitation under heavy acceleration
  • Loud whistling or chirping noise from the turbocharger
  • A boost pressure gauge may read higher than normal or fluctuate rapidly

Note that these symptoms can vary depending on the make and model of the vehicle. Consulting a professional mechanic or using a diagnostic tool may help determine the specific cause of the issue.


What causes the P0238 code?

Causes of the P0238 fault code may include:

  • Malfunctioning turbocharger/supercharger boost sensor
  • A short circuit or open circuit in the boost sensor wiring
  • Malfunctioning engine control module (ECM)
  • Boost pressure leak or restriction in the intake system
  • Malfunctioning turbocharger/supercharger wastegate
  • Incorrect vacuum hose connections.

Possible Solutions

How to fix P0238?

To fix the P0238 fault code on cars, the following steps can be taken:

  1. Check the Boost Pressure Sensor: Check if there are any loose connections or damaged wiring. If any, repair or replace them.

  2. Verify the Sensor Reading: A multimeter can be used to test the boost pressure sensor. Connect the multimeter to the sensor and check the voltage output. Compare the reading with the manufacturer's specification. If the reading is within the range, the sensor is functioning correctly.

  3. Inspect the Turbocharger: A malfunctioning turbocharger can cause high boost pressure, leading to fault code P0238. Check if there are any damaged or worn-out parts. If any, replace them.

  4. Check the Boost Pressure Control Valve: Sometimes, the boost pressure control valve may malfunction, leading to high boost pressure. Verify its operation and if faulty, replace it.

  5. Check the MAP Sensor: The Manifold Absolute Pressure (MAP) sensor measures the pressure inside the intake manifold. If the sensor is faulty, it may cause P0238. Check if there are any loose connections or damaged wiring, and replace the sensor if needed.

  6. Clean the Intake System: A clogged or dirty air intake system can cause high boost pressure, leading to fault code P0238. Clean the air intake system to improve airflow.

  7. Repair or Replace the PCM: If none of the above steps resolve the issue, the Powertrain Control Module (PCM) may be faulty. Consult with a professional mechanic to diagnose the problem. If needed, repair or replace the PCM.