|Trouble Code||Fault Location||Probable Cause|
|P2227||Barometric pressure (BARO) sensor- range/performance problem||Wiring, BARO sensor, ECM|
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What Does Code P2227 Mean?
OBD II fault code P2227 is a generic code that is defined as “Barometric pressure (BARO) sensor- range/performance problem”, and is set when the PCM (Powertrain Control Module) detects a reading from the Barometric Pressure Sensor that is incompatible or irreconcilable with the current engine load and throttle opening, or when its data does not correlate with that of the MAP (Manifold Absolute Pressure) sensor.
The input value of this sensor is compared to a reference voltage (usually 5V for most applications), and should a deviation from the expected value exist for a period of four consecutive seconds on most applications, the PCM will set code P2227, and illuminate a warning light.
As its name suggests, the function of the Barometric Pressure Sensor is to provide input data to the PCM with regards to the current atmospheric pressure, which changes (decreases) relative to the atmospheric pressure at sea level as the vehicle gains altitude. Working in conjunction with the MAP (Manifold Absolute Pressure) sensor, input data from the Barometric Pressure Sensor allows the PCM to calculate appropriate fuel delivery and ignition timing strategies that ensure that the engine always performs at its peak, regardless of the applications’ elevation above sea level.
For instance, if any given engine needs a throttle opening of say, 30% to develop X amount of power in first gear at sea level, that same engine will require a bigger throttle opening of say, 40% to allow more intake air to enter the engine to compensate for the less dense air at higher elevations above sea level. While the above is a grossly over simplified example to illustrate the principle, and should not be taken literally, it serves to show how more air is allowed to enter the engine.
In a fully functional system, both the MAP and IAT (Intake Air Temperature) sensors also provide input data to the PCM, and it is the combined data of all three sensors (among others) that ultimately determine the degree of throttle opening, volume and timing of fuel delivered, and adaptations to the ignition timing that ensures the engine delivers the same performance it would have done at sea level.
The image below shows a typical Barometric Pressure Sensor from a Ford application. Note that the appearance and location of the Barometric Pressure sensor varies greatly between applications, and in some cases, this sensor is incorporated into other sensors. For this reason it is very important to identify the correct sensor when diagnosing code P2227.
What are the common causes of code P2227?
Some common causes of code P2227 could include the following-
- Damaged, burnt, shorted, disconnected, or corroded wiring and/or connectors
- Clogged catalytic converter(s) and/or mufflers
- Serious exhaust leaks upstream of oxygen -, or NOx sensors
- Defective barometric sensor
- Defective throttle position sensor
- Defective, or contaminated MAF (Mass Airflow) sensor
- Defective manifold pressure sensor
- Defective IAT (Intake Air Temperature) sensor
- Engine in poor mechanical condition, or the presence of continuous misfire codes on one or more cylinders
- Unmetered air entering the engine
- Failed or failing PCM. Note that this is a rare event, and the fault must be sought elsewhere before any controller is replaced
What are the symptoms of code P2227?
Some common symptoms of code P2227 could include the following, but note that the severity of some driveability issues could vary greatly between applications-
- Stored trouble code and an illuminated warning light
- Fuel consumption may increase
- Some applications may exhibit a degree of power loss
- In some cases the engine may stumble, or hesitate upon acceleration
How do you troubleshoot code P2227?
NOTE #1: An accurate diagnosis of code P2227 requires that the engine be in perfect running condition, with no exhaust leaks, misfire codes, or engine vacuum leaks present. Failure to investigate and resolve any codes that precede P2227 will almost certainly result in a misdiagnosis, wasted time, and the unnecessary replacement of parts and components.
NOTE #2: On applications that are notorious (VW, Audi, BMW, and Mercedes) for their high rates of oil consumption, code P2227 is often set when the heated element on the MAF (Mass Airflow) sensor becomes heavily contaminated with oil and oily residues. On these applications, it is often possible to resolve the code with a simple cleaning of the element with an approved cleaner. Note however that if this, and all other repair attempts does not resolve P2227 and the MAF sensor has to be replaced, aftermarket replacements often cause a recurrence of this and other codes.
Record all fault codes present, as well as all available freeze frame data. This information can be of use should an intermittent fault be diagnosed later on.
NOTE: Refer to the notes immediately above, and make sure that all codes preceding code P2227 are resolved definitively before proceeding to Step 2.
Assuming that that no other codes are present, or that all other preceding codes have been repaired but P2227 persists, refer to the manual for the application to locate and identify the Barometric Pressure Sensor, as well as its associated connectors and wiring. Also determine the function and color-coding of all associated wiring to prevent the possibility of testing the wrong sensor, since some Barometric Pressure Sensors are incorporated into other sensors.
NOTE: Do not neglect to inspect the air filter element at this time, and replace it if it is dirty, clogged, broken, or damaged in any way. Also inspect the inlet tract for blockages or damage that could impede, limit, or inhibit the airflow through the ducting. Make repairs or replace parts as required.
If the code persists, perform a thorough visual inspection of all associated wiring and connectors. Look for damaged, burnt, shorted, disconnected, or corroded wiring and/or connectors. Make repairs or replace wiring as required. Clear all codes after repairs are complete, and operate the vehicle for at least one complete drive cycle before rescanning the system to see if the code returns.
If the code persists but there is no visible damage to wiring or connectors, perform resistance, reference voltage, continuity and if applicable, ground integrity checks on all relevant wiring. Compare all obtained readings to the values stated in the manual, and make repairs or replace wiring as required to ensure that all electrical values fall within the ranges specified by the manufacturer. Be sure to disconnect the barometric sensor’s circuit from the PCM during resistance checks to prevent damage to the controller.
NOTE #1: Pay particular attention to the reference voltage circuit, since an abnormal resistance in this circuit will almost always this code. If needs be, replace this wire instead of making repairs to it, since poorly executed repairs could cause problems and issues with other sensors/circuits, given the fact that several sensors may share this circuit.
NOTE #2: Bear in mind that the Barometric Pressure Sensor forms part of its control circuit, and as such, its internal resistance must be tested as well. Replace the sensor if its resistance does not match the specified value, since this value is a reasonably good indicator of its overall condition. Note that proper testing of this sensor may require the use of the manufacturers’ pressure-to-Hertz chart, which may not be included in the repair manual. If it is included, the manual will also provide proper instructions on how to use it, and how to interpret the results. Follow these instructions exactly to obtain the most accurate results.
Clear all codes after repairs are complete, and operate the vehicle for at least one complete drive cycle before rescanning the system to see if the code returns.
While he steps 1 through 5 will resolve code P2227 in nine out of every ten cases, it is possible for the code to persist despite there being no obvious cause. If this happens, remove, and clean the heated element of the MAF sensor, regardless of the application. Refit the MAF sensor after cleaning, clear all codes after repairs are complete, and operate the vehicle for at least one complete drive cycle before rescanning the system to see if the code returns.
If the fault still persists, suspect a faulty MAF sensor or a faulty PCM but since PCM failure is exceedingly rare, replace the MAF sensor. If the fault still persists after replacing the MAF sensor, suspect an intermittent electrical fault. However, faults of this type can be extremely challenging and time consuming to find, and in some cases it may be necessary to allow the fault to worsen considerably before an accurate diagnosis and definitive repair can be made.
Codes Related to P2227
NOTE: While the codes listed here are not strictly related to P2227 – “Barometric pressure (BARO) sensor- range/performance problem”, it is fairly common for one or more of the codes listed here to be present along with P2227. However, which codes on this list are likely to be present largely depends on the application and the exact root cause of P2227.
- P2226 – Relates to “Barometric Pressure Sensor “A” Circuit”
- P2228 – Relates to “Barometric Pressure Sensor “A” Circuit Low”
- P2229 – Relates to “Barometric Pressure Sensor “A” Circuit High”
- P222A – Relates to “Barometric Pressure Sensor “B” Circuit”
- P222B – Relates to “Barometric Pressure Sensor “B” Circuit Range/Performance”
- P222C – Relates to “Barometric Pressure Sensor “B” Circuit Low”
- P222D – Relates to “Barometric Pressure Sensor “B” Circuit High”
- P222E – Relates to “Barometric Pressure Sensor “B” Circuit Intermittent/Erratic”
- P222F – Relates to “Barometric Pressure Sensor “A”/”B” Correlation”
- P2230 – Relates to “Barometric Pressure Sensor “A” Circuit Intermittent/Erratic”