P2229 indicates the powertrain control module has detected a higher-than-expected voltage signal from the barometric pressure sensor circuit. The barometric pressure sensor provides atmospheric pressure data so the engine management system can compensate for altitude and adjust fuel delivery. A circuit high condition almost always points to an electrical fault rather than an actual change in ambient air pressure.
Internal failure of the sensor—or the integrated MAP/BARO sensor on some designs—can cause the signal voltage to exceed the calibrated limit, producing a false high reading.
Damaged insulation or chafing can allow the sensor signal wire to contact a battery-positive wire, forcing the circuit voltage above its normal range.
Corrosion, moisture intrusion, or loose and spread pins at the sensor or module connector can alter circuit resistance and raise the perceived voltage.
An open, broken, or high-resistance ground path can prevent proper voltage drop and cause the signal to read abnormally high.
A rare malfunction inside the PCM can misinterpret or incorrectly report a high barometric pressure signal; this should only be considered after sensor and wiring tests are complete.
No. A failed PCM is an uncommon cause of this code. Most instances are traced to a faulty sensor or a wiring short. PCM replacement should only occur after all sensor and circuit tests have been performed and confirmed normal.
Driving is generally possible for short distances, but incorrect barometric data can affect fuel trims and engine performance. Prompt diagnosis is recommended to avoid potential drivability issues.
No. P2229 is an electrical circuit fault indicating the voltage is above the expected range, not a report of unusually high ambient air pressure.
Not necessarily. On many engines the BARO function is integrated into the manifold absolute pressure sensor or located inside the PCM. The specific configuration depends on the vehicle design.