P0129 — Barometric Pressure Too Low
What it means: Barometric Pressure Too Low.
How serious / can you keep driving: Informational. Usually OK to continue — monitor closely.
Check first: Compare BARO reading to expected pressure at altitude
Don't risk it — look up listed providers near you and give them this code when you call.
Listed providers nearest Salt Lake City, UT
Closest first. Tell them P0129 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.
- 0.0 mi away — based in Salt Lake City, UT · (801) 531-9256
- 0.0 mi away — based in Salt Lake City, UT · (385) 503-8084
- 0.0 mi away — based in Salt Lake City, UT · (385) 386-4700
Seen on: Heavy Truck
What P0129 means
Barometric Pressure Too Low. Common causes: BARO sensor reading below minimum.
How serious is it?
Informational. Usually OK to continue — monitor closely.
Most likely causes
- BARO sensor reading below minimum
- Sensor failure
- ECM altitude error
First moves (roadside)
- Compare BARO reading to expected pressure at altitude
- replace sensor if off by >0.5 psi
FAQ
Barometric Pressure Too Low. Common causes: BARO sensor reading below minimum.
Informational — Usually OK to continue — monitor closely.
The most common cause is: BARO sensor reading below minimum. Other possibilities include Sensor failure; ECM altitude error.
Usually OK to continue — monitor closely. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Related codes
Codes that commonly appear alongside P0129, or share the same subsystem.
- Engine Protection — Power Derate Active (SPN 1569 FMI 31)
- Intake Manifold (Charge Air) Temp — High (SPN 105 FMI 0)
- Turbo Boost Pressure — High / Overboost (SPN 1127 FMI 16)
- Boost pressure high (SPN 102 FMI 0)
- Boost sensor — voltage low (SPN 102 FMI 4)
- Intake manifold temp — voltage high (SPN 105 FMI 3)
- Intake manifold temp — voltage low (SPN 105 FMI 4)
- Injection control pressure low (HEUI — older engines) (SPN 164 FMI 1)
Find a mechanic or related guides
General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.