What causes a P0709 code?

P0709 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 P0709 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0709 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

P0709

Transmission Range Sensor Circuit Intermittent

What it means

The Transmission Control Module (TCM) is receiving erratic or inconsistent signals from the transmission range sensor (neutral start switch), preventing the vehicle from accurately determining the shift lever position.