What causes a P0485 code?

P0485 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 P0485 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0485 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

P0485

Fan Cooling Control Circuit Power/Ground Fault

What it means

The engine control module (ECM) provides a ground or power signal to the cooling fan clutch or solenoid; this code sets when there is an electrical mismatch in that feedback circuit.