P0299 — Turbocharger Underboost Condition
Seen on: Cummins ISX/ISM/ISB · Detroit DD15/DD13 · Paccar MX13
Turbocharger Underboost Condition. Common causes: Boost leak, worn turbo vanes, plugged intercooler.
Your code rides along, so nearby mechanics see the fault before they quote you.
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.
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.