What causes a P0189 code?

P0189 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 P0189 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0189 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

P0189

Fuel Temperature Sensor B Circuit Intermittent

What it means

The Engine Control Module detects an erratic or intermittent voltage signal from the fuel temperature sensor circuit, specifically labeled as sensor B which is often located on the return line or the high-pressure fuel rail housing.