Technical Description of OBD-II Trouble Code
Intermittent Circuit Issue with Turbo Boost Control Position Sensor “B”
What does that signify?
This diagnostic trouble code (DTC) is a generic powertrain code that applies to OBD-II equipped vehicles with a turbocharger (Ford, GMC, Chevrolet, Hyundai, Dodge, Toyota, etc.). While it is a generic code, the specific repair steps may vary depending on the make and model of the vehicle.
This trouble code can generally apply to all turbocharged OBDII equipped engines, but it is more commonly found in certain Hyundai and Kia vehicles. The Turbo Boost Control Position Sensor (TBCPS) converts the turbo boost pressure into an electrical signal for the Powertrain Control Module (PCM).
The Turbo Boost Control Position Sensor (TBCPS) provides additional information about turbo boost pressure to the Powertrain Control Module or PCM. This information is typically used to fine-tune the amount of boost provided to the engine by the turbocharger.
The boost pressure sensor provides the PCM with the remaining information required for turbo boost pressure calculations. Whenever there is an electrical issue with the TBCPS, depending on how the manufacturer wants to identify the fault, the PCM will set code P2590. This code is specifically related to an electrical circuit fault.
It also examines the voltage signal from the TBCPS sensor to determine if it is correct during initial Key On Engine Off. This code may have been triggered by mechanical issues (typically exhaust back pressure or intake restrictions) or electrical issues (boost pressure sensor/boost control position sensor circuit).
Troubleshooting steps may vary depending on the manufacturer, type of sensor, and wire colors connected to the sensor. Consult a vehicle-specific repair guide to identify the “B” sensor for your particular vehicle.
Related turbo boost control position sensor “B” circuit codes:
Symptoms
Symptoms of a P2590 code may include:
Causes
Possible causes for this code to be set are:
Diagnostic and Repair Procedures
A good starting point is always to check for technical service bulletins (TSB) for your particular vehicle. Your issue may be a known issue with a known fix provided by the manufacturer, which can save you time and money during diagnosis.
Next, locate the TBCPS sensor on your particular vehicle. This sensor is usually found directly screwed/bolted into the turbocharger housing. Once located, visually inspect the connector and wiring. Look for scraping, rubbing, bare wires, burn spots, or melted plastic. Pull the connector apart and carefully inspect the terminals (the metal parts) inside the connector. Check if they appear burned or have a green tint indicating corrosion. If necessary, clean the terminals using electrical contact cleaner and a plastic bristle brush. Allow them to dry and apply electrical grease where the terminals make contact.
If you have a scan tool, clear the diagnostic trouble codes from memory and check if the P2590 code returns. If it does not, then the issue was most likely related to the connections.
If the P2590 code does return, ensure that you have good turbo boost pressure by testing it with a mechanical gauge. Refer to the manufacturer’s specifications for your vehicle. If the boost pressure does not meet the requirements, identify the root problem for the low boost pressure (possible exhaust restrictions, wastegate issue, bad turbocharger, intake leaks, etc.), clear the codes, and retest. If the P2590 code no longer appears, then the issue was mechanical in nature.
If the P2590 code continues to appear, we will need to test the TBCPS sensor and its associated circuits. With the Key Off, disconnect the electrical connector at the TBCPS sensor. Connect a Digital Voltmeter’s black lead to the ground terminal at the TBCPS sensor wiring harness connector. Connect the red lead of the Digital Voltmeter to the power terminal at the TBCPS sensor wiring harness connector. Turn the Key On Engine Off. Check the manufacturer’s specifications; the voltmeter should read either 12 volts or 5 volts. If not, repair any open wiring on the power or ground wire, or replace the PCM.
If the previous test is successful, we will need to test the signal wire. With the connector still disconnected, move the red lead of the voltmeter from the power wire terminal to the signal wire terminal. The voltmeter should now read 5 volts. If not, repair any open wiring on the signal wire, or replace the PCM.
If all previous tests have passed and you continue to receive a P2590 code, it most likely indicates a failed TBCPS sensor. However, a failed PCM cannot be ruled out until the TBCPS sensor has been replaced. If you are unsure, seek assistance from a trained automotive diagnostician. PCMs must be programmed or calibrated to the vehicle in order to be installed correctly.
