Technical Description of OBD-II Trouble Code
Correlation between Barometric Pressure and Turbocharger/Supercharger Inlet Pressure
What does that signify?
This generic powertrain diagnostic trouble code (DTC) is commonly found in many OBD-II vehicles, including those from Dodge, Cadillac, Fiat, Jeep, Nissan, Chrysler, etc.
A stored code P006D indicates that the powertrain control module (PCM) has detected a discrepancy in the signals between the barometric pressure sensor and the turbocharger/supercharger inlet pressure sensor.
The code P006D is only applicable to vehicles with forced air induction systems. Any other stored codes related to the barometric pressure sensor or forced air induction system should be addressed before diagnosing a code P006D.
The barometric pressure, which represents air density, is measured in kilopascal (kPa) units or inches of mercury (Hg) using the barometric pressure sensor. These measurements are converted into varying degrees of voltage and input to the PCM. Barometric pressure and its signals are measured in similar increments.
The turbocharger/supercharger inlet pressure sensor is designed similarly to the barometric pressure sensor and also monitors air density. It is usually located inside the turbocharger/supercharger inlet hose and provides the PCM with a corresponding voltage signal.
If the voltage input signals between the barometric pressure sensor and the turbocharger/supercharger inlet pressure sensor differ by more than a programmed degree over a certain period of time and under specific circumstances, a code P006D will be stored, and the malfunction indicator lamp (MIL) may illuminate.
In some cases, MIL illumination may require multiple drive cycles with a failure. The exact parameters for code storage specific to the vehicle in question can be obtained from a reliable vehicle information source, such as AllData DIY.
What is the severity of this DTC?
The conditions leading to the storage of a code P006D are likely to hinder engine performance, drivability, and fuel efficiency. It should be addressed urgently.
What are some of the symptoms of the code?
Symptoms of a P006D engine code may include:
What are some of the common causes of the code?
Possible causes for this engine code may include:
What are some P006D troubleshooting steps?
To begin troubleshooting a code P006D, visually inspect all wiring and connectors related to the barometric pressure sensor and turbocharger inlet pressure sensor. Ensure that the turbocharger/supercharger inlet hoses are securely connected and in good condition. Additionally, inspect the air filter to ensure it is relatively clean and free from obstructions.
When diagnosing a code P006D, you will need a manual vacuum pressure gauge, a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable source of vehicle information.
A recommended preliminary step before addressing any barometric pressure sensor related code is to perform a manual engine intake vacuum pressure test. Use the vacuum pressure gauge and refer to the specification guidelines provided by your vehicle information source. If the engine vacuum is insufficient, there may be an internal engine malfunction that needs to be resolved before proceeding.
Next, connect the scanner to the vehicle’s diagnostic port and retrieve all stored codes and freeze frame data. Freeze frame data provides information about the exact circumstances at the moment of the malfunction that led to the storage of the code P006D. Take note of this information as it may be helpful during the diagnosis process. Clear the codes and test-drive the vehicle to see if the code is reset.
If the code is reset:
If the appropriate reference voltage and ground are present:
If the respective sensors comply with the manufacturer’s specifications:
If the correct barometric pressure sensor and turbocharger/supercharger inlet pressure sensor voltage signals are present:
If all barometric pressure/turbocharger/supercharger inlet pressure sensors and circuits are within specifications and there are no issues with the wiring or connectors:
