P0129
Barometric Pressure Too Low
Barometric pressure reading below the plausible minimum. Either operating at extreme altitude or sensor fault.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- Sensor reading drifted lowCommon
Parts involved
- Barometric Pressure Sensor
P0129 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.