P2227: Barometric Pressure Sensor A Circuit Range/Performance
What to do
The car will usually drive with slightly incorrect fuelling. If a separate barometric sensor is fitted, ask for its air port and hose to be checked for blockage before it is replaced — a blocked port produces a steady, believable, wrong reading and costs nothing to clear. Otherwise this generally points at the manifold pressure sensor, which does the same job on most engines.
What this code means
The barometric reading is electrically valid but does not agree with what the module expects — normally because it disagrees with another pressure source, or because it has not changed when it should have.
The comparison is usually against the manifold pressure sensor at key-on, when the two should read identically because the engine is not running and the manifold is at atmospheric pressure. That check is the reason the fault is caught at all, and it is also why a genuine MAP sensor drift shows up here rather than only in the MAP codes.
A second and cheaper cause is worth eliminating first on any engine where a dedicated sensor is fitted: the sensor's port or hose blocked. These sensors sample ambient air through a small opening, and an opening in an engine bay eventually collects dirt, oil mist or the remains of an insect. A blocked port gives a reading that is stable, plausible and wrong — which is exactly what fails a correlation check while passing every electrical test.
Altitude is worth stating explicitly here, because a correct reading looks alarming to anyone expecting sea-level figures. Atmospheric pressure genuinely falls by roughly a sixth at a thousand metres. A workshop diagnosing this at altitude should be comparing against what is correct there, not against a sea-level number.
Likely causes
Start here
Less common
- Faulty barometric pressure sensor · easy
- Corroded or loose connector · easy
- Vacuum leak in intake manifold or hoses · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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