P0944 Hydraulic Pressure Unit Loss of Pressure

P0944 indicates hydraulic pressure unit loss of pressure. The system cannot maintain expected pressure for actuator or shift operation.

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 keep operating an automated transmission with confirmed pressure loss; clutch or actuator damage can follow.

Symptoms of P0944

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 P0944

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

Compare commanded pressure build, actual pressure data, pump operation, relay command, cycling interval, and hydraulic temperature.
Inspect fluid level, leaks, accumulator function, pressure unit seals, pump output, pressure sensor plausibility, and related actuator faults.
Identify whether pressure loss occurs during engagement, repeated shifts, hot operation, or after sitting.

Related OBD-II codes

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