P0299 — Turbocharger Underboost Condition
What it means: Turbocharger Underboost Condition.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Start with the most likely cause: Boost leak.
Don't risk it — look up listed providers near you and give them this code when you call.
Listed providers nearest Baltimore, MD
Closest first. Tell them P0299 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 Baltimore, MD · (443) 680-6789
- 0.0 mi away — based in Baltimore, MD · (410) 544-3888
- 24 hour Mobile Diesel Truck Engine Repair DEF Repairs On Site Services Road Service Laptop Diagnostic Tractors & Dump Truck☎ Call0.0 mi away — based in Baltimore, MD · (443) 591-3631
Seen on: Cummins ISX/ISM/ISB · Detroit DD15/DD13 · Paccar MX13
What P0299 means
Turbocharger Underboost Condition. Common causes: Boost leak, worn turbo vanes, plugged intercooler.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- Boost leak
- worn turbo vanes
- plugged intercooler
- Faulty MAP sensor
- restricted air filter
- EGR valve stuck open
FAQ
Turbocharger Underboost Condition. Common causes: Boost leak, worn turbo vanes, plugged intercooler.
Serious — Power derate likely — plan to stop soon.
The most common cause is: Boost leak. Other possibilities include worn turbo vanes; plugged intercooler; Faulty MAP sensor; restricted air filter; EGR valve stuck open.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Related codes
Codes that commonly appear alongside P0299, 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)
Same symptom: Low boost / low power
Other air-path codes that arrive as a truck that will not pull the hill it pulled yesterday.
- Turbo boost pressure high (SPN 1127 FMI 0) · Engine
- Turbo compressor inlet temp high voltage (SPN 1172 FMI 3) · Engine
- Turbo compressor inlet pressure — high voltage (SPN 1176 FMI 3) · Engine
- VGT actuator position — not responding (SPN 2795 FMI 7) · Engine
- VGT position — not responding (similar to 2795) (SPN 5571 FMI 7) · Engine
- Turbo turbine inlet temp — high voltage (SPN 5856 FMI 3) · Engine
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.