What causes a P1054 code?

P1054 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a P1054 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P1054 active.

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

OBD-II

P1054

SFS Downhill Speed Controller Plausibility fault

What it means

P1054 indicates that the Downhill Speed Controller (part of the SmartFuel system) has detected a speed or deceleration value that does not align with expected logic, suggesting a calculation or sensor input error.