What does P0238 mean?
The boost pressure sensor reads intake pressure after the turbocharger.
The signal is reading higher than the sensor can normally produce, which points at a wiring fault or a dead sensor.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Check engine light
- Reduced power or limp mode
- Black smoke on diesels
Common causes
- Open sensor ground wire
- Signal wire shorted to the 5 V reference or to battery voltage
- Water in the connector
- Failed sensor
How to diagnose P0238
- Check the sensor ground first: an open ground drives the signal high.
- Unplug the sensor: if the signal still reads high, look for a short to voltage in the harness.
- If the wiring is good, replace the sensor.
- Key on, engine off, the reading should match barometric pressure.
- Check the port for oil and carbon.
How to fix it
- Clean the port
- Replace the sensor
- Repair wiring
Estimated repair cost
Likely repairs for P0238 run from about $100 to $350, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| Boost/MAP sensor (diesel) | $100 - $350 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0238?
Moderate severity
Drivable with care; power will likely be limited.
P0238 FAQ
What does P0238 mean?
P0238 stands for "Turbocharger/Supercharger Boost Sensor "A" Circuit High". The boost pressure sensor reads intake pressure after the turbocharger.
Can I drive with a P0238 code?
Drivable with care; power will likely be limited.
How much does it cost to fix P0238?
It depends on the cause. The likely repairs for P0238 range from about $100 to $350 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0238?
The most common causes are: open sensor ground wire; signal wire shorted to the 5 V reference or to battery voltage; water in the connector.