P0799 Pressure Control Solenoid C Intermittent

P0799 indicates an intermittent pressure control solenoid C fault. The solenoid C control circuit or response becomes unreliable only under some 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 clear an intermittent pressure-control code without heat, vibration, and connector checks.

Symptoms of P0799

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 P0799

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

Graph solenoid C command, pressure data, shift timing, slip, and fluid temperature during road tests that match freeze-frame data.
Inspect internal harness movement, case connector pin fit, terminal corrosion, fluid intrusion, and heat-related circuit dropouts.
Check whether harsh shifts, flare, limp mode, or pressure-control faults occur after warm-up, vibration, or heavy load.

Related OBD-II codes

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