What is the code for the turbocharger boost control position sensor?
The issue you’re asking about does not have a single universal DTC. In most vehicles, problems with boost control are flagged by boost-related codes or by sensor-circuit codes for the boost sensor. Common examples include P0299 (Turbocharger Underboost), P0234 (Turbocharger Overboost), and P0236-P0239 (boost sensor circuit range/high/low/intermittent). The exact code depends on your car’s make, model, and the OBD-II implementation. Use an OBD-II scanner to pull the primary code and any related data.
What is the boost control position sensor?
On some turbo systems—particularly those with variable geometry turbos (VGT/VNT) or electronic wastegate actuators—a boost control position sensor monitors the actuator or vane position to help the ECU regulate boost. In many engines, this sensor is integrated into the actuator assembly, and some manufacturers do not expose a separate “boost control position sensor” as a distinct diagnostic item. Instead, the ECU monitors boost pressure (MAP sensor) and actuator position indirectly, and codes may reflect sensor or actuator faults rather than a standalone position sensor fault.
Where it fits in the boost control system
In VGT/VNT systems, the actuator moves the vanes to set boost. The position sensor provides feedback to the engine computer so it can compare commanded versus actual boost. If the sensor, its wiring, or the actuator is out of spec, the ECU may trigger a DTC and adjust or limit boost to protect the engine.
Common diagnostic trouble codes related to boost control
Below are DTCs you’re likely to encounter when boost control or its sensor is at issue. The exact description can vary by manufacturer, but these codes are widely used across brands.
- P0299 – Turbocharger Underboost Condition
- P0234 – Turbocharger/Supercharger Overboost Condition
- P0236 – Turbocharger Boost Sensor A Circuit Range/Performance
- P0237 – Turbocharger Boost Sensor A Circuit Low Input
- P0238 – Turbocharger Boost Sensor A Circuit High Input
- P0239 – Turbocharger Boost Sensor A Circuit Intermittent/Failure
Concluding note: You might see only a P0299 or P0234 on your scanner, or you may see one of the boost sensor circuit codes (P0236-P0239). Always verify with the vehicle’s OEM diagnostic documentation and your scan tool’s supported definitions for the exact model.
How to diagnose a boost control sensor fault
To investigate a suspected boost control position sensor fault, follow a structured diagnostic approach:
- Record all current and pending DTCs and review freeze-frame data to understand the operating conditions when the fault occurred.
- Inspect intake, intercooler, and vacuum/boost lines for leaks, kinks, or damage that could affect boost readings.
- Check wiring and connectors to the boost control actuator, solenoid, and any position sensor for corrosion, damage, or loose connections.
- Test the boost control solenoid/actuator according to the service manual, ensuring proper electrical resistance and responsive operation to commanded signals.
- Review live data: commanded boost vs. actual boost, actuator position, and sensor readings (MAP/boost sensor). Look for mismatches or sensor bias that could indicate a faulty sensor or wiring.
- If the system has a dedicated vane/position sensor, test its output against specified ranges and replace the sensor or actuator if out of spec.
Concluding note: Many boost control problems originate from vacuum leaks or actuator issues rather than a faulty sensor alone. A thorough diagnostic of the entire boost-control path helps prevent unnecessary part replacement.
Do you need the exact code for your car?
Because DTC wording and codes differ by brand, consult your owner’s manual, service documentation, or the dealer/repair manual for the precise definition of any code displayed on your vehicle. A professional scan with live data is the best way to determine whether the fault lies with the boost control position sensor, the actuator, or another component such as the MAP sensor or a vacuum leak.
Summary
There is no universal “turbo boost control position sensor code.” Expect related codes tied to boost levels (P0299 for underboost, P0234 for overboost) or boost-sensor circuit faults (P0236–P0239). Accurate diagnosis relies on interpreting live data, inspecting wiring and actuators, and cross-referencing manufacturer documentation. When in doubt, seek a qualified technician to confirm the exact cause and recommended repair.
