What causes a P0797 code?

P0797 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 P0797 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0797 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

P0797

Pressure Control Solenoid C Stuck On

What it means

The Electronic Control Module (ECM) or Transmission Control Module (TCM) has detected that pressure control solenoid 'C' is stuck in the 'on' position, preventing proper gear ratio changes or engagement.