P0779 Pressure Control Solenoid B Intermittent

P0779 indicates an intermittent pressure control solenoid B fault. Line-pressure control or its circuit drops out under certain conditions.

Code details

Generic OBD-II · P0

System: Transmission
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not treat harsh or soft shifts as proof of solenoid failure without pressure and command data.

Symptoms of P0779

Harsh, delayed, or slipping shifts, or being stuck in one gear.
Check-engine light, sometimes with limp-home mode.
Flaring RPM or a shudder under load.

Common causes of P0779

Low or degraded transmission fluid.
A failing speed sensor, shift solenoid, or pressure-control circuit.
Wiring, connector, or internal hydraulic/mechanical faults.

Useful checks before replacing parts

Monitor pressure control solenoid B command, pressure data, slip, shift feel, and fluid temperature during the fault.
Inspect connector fit, internal harness condition, solenoid resistance, case connector pins, and heat or vibration sensitivity.
Check for related pressure-control, ratio, or transmission temperature codes that can point to the same root cause.

Related OBD-II codes

These nearby transmission entries can help compare wording and pin down the fault area.