P2599 indicates that the turbocharger boost control position sensor is reporting a voltage signal that is stuck at a high level (above the expected range). This code is set when the engine control module detects the sensor reading is not changing as commanded, often due to a sensor fault, wiring issue, or mechanical binding in the boost control system.
The sensor itself is the most common failure. Internal electronic damage or a stuck wiper can cause the signal to remain high regardless of actual actuator position.
A wiring short to battery voltage or a 5V reference line can force the signal high. This may be due to chafed wires, corrosion, or damaged connectors.
If the actuator (wastegate or variable vane mechanism) is stuck in a position that keeps the sensor reading high, the code can set. Carbon buildup or seized linkage are common causes.
A poor ground connection can cause the sensor signal to float high. Check for corroded ground terminals or broken wires in the sensor return circuit.
Rare, but a corrupted calibration or internal ECM failure can misinterpret a valid sensor signal. This is the least likely cause and should only be considered after all other possibilities are ruled out.
It is not recommended to drive long distances with this code. The vehicle may enter limp mode, reducing power and potentially causing further damage to the turbo or engine if boost is uncontrolled.
Usually not. The code points to the boost control position sensor or its circuit, not the turbo itself. Only replace the turbo if a mechanical inspection reveals a seized wastegate or vanes that cannot be freed.
No. Many drivers are told to replace the ECM, but that is almost never the correct fix for this code. The sensor, wiring, or actuator are far more likely. Only consider ECM after thorough diagnosis of all other components.
Cost varies widely by vehicle and cause. A simple sensor replacement may be inexpensive, while diagnosing and repairing wiring or a stuck actuator can be more labor-intensive. Always get a proper diagnosis before authorizing repairs.