What causes a SPN 2805 code?

SPN 2805 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 SPN 2805 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 2805 active.

How do I fix SPN 2805?

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

J1939 SPN

SPN 2805

SPN 2805 FMI 14 - High Pressure Fuel Rail Pressure Signal Mismatch

What it means

The Engine Control Module detects a significant discrepancy between the fuel rail pressure sensor signal and the expected values based on high-pressure pump commands.