What causes a P0665 code?

P0665 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 P0665 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0665 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

P0665

P0665 Intake Manifold Tuning Valve Control Circuit High

What it means

The Engine Control Module (ECM) detects a high voltage signal on the Intake Manifold Tuning Valve (IMTV) control circuit, indicating a potential short to power or a failed solenoid.