P2228: Barometric Pressure Sensor A Circuit Low
What to do
Expect hesitation and reduced power, because the module is fuelling for air far thinner than it actually is. Check the wiring and connector — a shorted signal wire is the usual cause. On most engines this points at the manifold pressure sensor rather than a separate barometric one.
What this code means
The barometric pressure circuit reads below its valid range — a short to ground, or a reported pressure lower than anywhere on Earth would produce.
That second case is what distinguishes this from the range/performance code. A pressure sensor reporting a plausible-but-wrong altitude fails the correlation check at P2227; one reporting a pressure below what exists at any habitable altitude is reporting a circuit fault, and the module treats it as such.
The practical effect on fuelling is that the module believes the air is extremely thin and reduces fuel accordingly, which produces a lean condition and its symptoms — hesitation, poor power, and pinking under load on a hot day. Where the module has a default it falls back to, the effect is milder and the code may be the only sign.
Likely causes
Start here
- Wiring shorted to ground · moderate
- Faulty manifold absolute pressure sensor · easy
- Corroded or loose connector · easy
Less common
- Faulty barometric pressure sensor · easy
- Damaged wiring harness · moderate
Symptoms
Components involved
Information, not instruction
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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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