What causes a P1181 code?

P1181 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 P1181 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P1181 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

P1181

Fuel temp rate of change fault

What it means

The ECM monitors the fuel temperature sensor to ensure the heat increase or decrease stays within a logical 'rate of change.' This code sets when the temperature changes more rapidly than the engine mapping allows.