MAP / Boost Sensor High

P0238 on a MaxxForce 13 (12.4L) (2008-2014) indicates: MAP / Boost Sensor High. This is a known fault code on the MaxxForce engine family and typically points to the causes listed above.

Yes, you can generally drive with this code, but diagnose soon to prevent secondary damage.

Repair cost is typically $120-$450 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.

California's heavy-duty OBD regulation sets the underboost trip point where a decrease from commanded or expected boost would push NMHC, CO or NOx past 2.0 times the applicable standards, or PM past the standard plus 0.02 g/bhp-hr (Title 13 CCR 1971.1, section (e)(4.2.1)). As with EGR, it must also flag the system reaching its control limits without achieving commanded boost — worth knowing before condemning a turbo that is physically moving. This threshold comes from the heavy-duty OBD regulation, which covers 2010 and later heavy-duty engines. If your engine is in a pickup at or under 14,000 lb GVWR it is certified under the separate medium-duty rule instead, so treat this as the design intent rather than your engine's exact limit.