What causes a P0779 code?

P0779 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 P0779 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0779 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

P0779

P0779 Pressure Control Solenoid E Intermittent

What it means

Indicates the Transmission Control Module (TCM) has detected an intermittent or erratic electrical signal from the pressure control solenoid 'E' circuit. This solenoid manages hydraulic fluid pressure required for smooth gear engagement.