P0944
Hydraulic Pressure Unit Loss of Pressure
TCM detects rapid loss of hydraulic pressure in transmission accumulator or main pump circuit.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: shop_only
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Common causes
Ordered by how often each turns out to be the cause.
- Accumulator leakCommon
- Pump seal failedPossible
Parts involved
- Hydraulic Accumulator
- Transmission Pump
- Valve Body
P0944 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.