What causes a P0786 code?

P0786 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 P0786 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0786 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

P0786

Shift Solenoid A Range or Performance Malfunction

What it means

The Transmission Control Module (TCM) has detected an unexpected gear ratio or lack of solenoid engagement when attempting to command Shift Solenoid A. This indicates a mechanical or electrical mismatch between the commanded gear and the actual gear state.