Technical Description of OBD-II Trouble Code
Low Barometric Pressure Sensor A
What does that signify?
This is a generic diagnostic trouble code (DTC) for powertrain issues and is commonly found in OBD-II vehicles. It can affect various vehicle brands such as Chevy, Mazda, Volvo, Acura, Honda, BMW, Isuzu, Mercedes Benz, Cadillac, Hyundai, Saab, Ford, GMC, etc. The specific repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle.
Most Engine Control Modules (ECMs) rely on multiple measurements to ensure an optimal air to fuel ratio for the engine. The ideal air/fuel ratio is known as the “stoichiometric” mixture, which is 14.7 parts air to one part fuel. The ECM monitors various values such as air flow, coolant temperature, engine speed, load demand, atmospheric temperature, etc., to maintain the stoichiometric mixture. Some engine management systems prioritize intake and atmospheric pressures for optimizing the mixture.
In some cases, Barometric Air Pressure (BAP) sensors are used alongside Manifold Absolute Pressure (MAP) sensors. BAP sensors measure atmospheric pressure, which is crucial for determining fuel mixtures. The ECM compares atmospheric pressures with intake manifold pressures to accurately adjust the fuel mixture based on the driver’s needs. Altitude plays a significant role in diagnosing BAPs, as symptoms may worsen or improve depending on the location, especially in mountainous areas.
When an OBD2 fault code includes a letter (such as “A”), it often indicates a specific aspect of the system being addressed, such as different banks, sensors, circuits, connectors, etc. In this case, the letter “A” helps identify the specific sensor involved. Multiple barometric sensors are often used to ensure accurate readings and facilitate fuel management. Additionally, these sensors help identify faults within the sensors or circuits. Consult your service manual for precise details regarding letter specifications for your particular vehicle.
P2228 is triggered by the ECM when it detects a low electrical value/reading from the Barometric pressure (BAP) “A” sensor or its circuit(s).
A barometric pressure sensor:
What is the severity of this DTC?
The severity of this DTC is moderately high. It is important to address this issue promptly to ensure efficient engine operation. If a fault can directly impact critical values like air/fuel ratios and is actively present, it is advisable not to operate the vehicle to prevent potential engine damage. However, if you have driven the vehicle since the fault occurred, there may not be immediate cause for concern. Nevertheless, if left unattended, this fault could lead to expensive internal engine damage in the future.
What are some of the symptoms of the code?
Symptoms associated with a P2228 trouble code may include:
What are some of the common causes of the code?
Possible causes for the P2228 code include:
What are some P2228 troubleshooting steps?
Basic Step #1
Locate the Barometric Air Pressure (BAP) sensor in your specific vehicle. The sensor’s location can vary significantly, so it is crucial to find the correct sensor. Once found, inspect the BAP sensor for any physical damage. Consider the sensor’s surroundings, such as high heat areas, engine vibrations, exposure to elements/road debris, etc.
Basic Step #2
Ensure that the connector on the sensor is properly seated to establish a good electrical connection. If the sensor is located on the engine, vibrations may cause connections to loosen or become physically damaged.
NOTE: Remember to disconnect the battery before disconnecting any sensors to avoid damaging electrical spikes. If you are uncomfortable or have limited electrical knowledge, it is recommended to have your vehicle towed/driven to a reputable repair facility.
Basic Step #3
Check for any obstructions that may be affecting the sensor. Obstructions can lead to false atmospheric pressure readings, which can impact engine performance in fuel management systems.
Basic Step #4
Using a multimeter, compare the desired electrical values for the barometric air pressure sensor with the actual values. To access the pins, disconnect the connector from the sensor. If the values fall outside the specified range, it indicates a defective sensor. Replace the sensor following the appropriate removal and installation procedures.
