What causes a P171D code?

P171D 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 P171D code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P171D 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

P171D

EMTVP T3 model disable diagnosis

What it means

EMTVP T3 model disable diagnosis - This code indicates the Engine Control Module (ECM) has disabled the temperature model 'T3' verification logic due to an internal calculation error or invalid input data.