Turbo Underboost
The MAXXFORCE-P0299-11 (MaxxForce) diesel fault code means: Turbo Underboost. This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- advanced
- Estimated cost
- $800-$6,000
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Common Symptoms
- Low power
- Derate
- CEL
Probable Causes (Ranked by Likelihood)
- VGT vane actuator failure Very Likely
- Plugged or cracked high-pressure turbo Likely
- Exhaust restriction from plugged DPF Possible
Step-by-Step Diagnostic Procedure
Inspect VGT operation via service tool.
Check high-pressure turbo shaft play.
Frequently Asked Questions
What is P0299 on a MaxxForce 11 (10.5L)?
P0299 on a MaxxForce 11 (10.5L) (2008-2014) indicates: Turbo 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 $800-$6,000 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.