P0798 Pressure Control Solenoid C Electrical

P0798 points to an electrical fault in pressure control solenoid C. The circuit for controlling line pressure is open, shorted, or outside expected electrical behavior.

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 diagnose this as a hydraulic pressure problem until the electrical control circuit has been tested.

Symptoms of P0798

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 P0798

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

Check solenoid C feed voltage, driver control, resistance, current draw, connector fit, and continuity under loaded conditions.
Inspect the transmission case connector, internal harness, fluid intrusion, pin tension, and harness damage near heat or movement points.
Compare commanded pressure control with actual pressure, shift feel, and any related ratio or pressure-control codes.

Related OBD-II codes

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