Turbocharger Underboost
The MAXXFORCE-P0299-DT (MaxxForce) diesel fault code means: Turbocharger Underboost. This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- advanced
- Estimated cost
- $300-$3,000
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Common Symptoms
- Low power
- Black smoke on acceleration
- CEL
Probable Causes (Ranked by Likelihood)
- Sticking VGT vanes from soot Very Likely
- Leaking charge air cooler or boot Likely
- Failed turbo actuator Possible
Step-by-Step Diagnostic Procedure
Pressure test the CAC for leaks.
Command VGT actuator sweep via NavKal / MD.
Clean or replace turbo if vanes stuck.
Frequently Asked Questions
What is P0299 on a MaxxForce DT (7.6L)?
P0299 on a MaxxForce DT (7.6L) (2007-2015) indicates: Turbocharger Underboost. This is a known fault code on the MaxxForce engine family and typically points to the causes listed above.
Can I drive with P0299 on my MaxxForce?
Only drive short distances to reach a repair facility. Continued operation may cause further damage or progressive derate.
How much does it cost to fix MaxxForce P0299?
Repair cost is typically $300-$3,000 depending on the underlying cause and shop rate. Many MaxxForce faults (especially EGR cooler, head bolt, and VGT repairs) are major expenses that drove fleet owners to repower with Cummins or retire these trucks early.