What P0944 means
The pump runs but the expected hydraulic pressure does not build or collapses.
How the engine computer detects it
Stellantis names it Loss of Hydraulic Pump Prime: a 2023 STAR case lists it with P0868 and a slow engagement after the vehicle has stood, both set as the only transmission codes with the MIL on, and the fix was a new transmission; an FCA defect file from 2015 also shows it beside line pressure low. Mercedes uses P0944 on the 722.9 automatic with electric auxiliary oil pump for stop-start, as internal fault of that pump; stop-start stops working, and a leaking check valve between converter housing and pump is one cause. Ferrari reads it on its DCT as no system pressure signal with pressure loss. P0943 covers short cycles, P0868 low fluid pressure.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine or transmission warning light on
- Slow engagement after the vehicle has been parked
- Auto stop-start not available or engine restarts at once
- Slipping, no drive or limp mode
Common causes
- Pump loses prime (air drawn in through filter, seal or strainer pipe) Most likely
- Blocked oil strainer or suction tube Possible
- Worn or failed pump (mechanical or electric) Possible
- Leaking check valve or internal leak in the valve body Less likely
How to diagnose P0944
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: hydraulic pressure unit, tcm.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Vehicles that report P0944 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Chrysler Town and Country | 2013–2016 | 4 | 61k | |
| Dodge Grand Caravan | 2016 | 3 | — |
Counts of owner complaints to the NHTSA that mention P0944 (11 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 9
- Transmission
- 44
- Specific fault
Questions drivers ask
Can I drive with code P0944?
Drive gently and only as far as you need to. The engine computer may limit power to protect the engine, so avoid highways and heavy traffic until it's fixed. If the check engine light starts flashing, pull over.
Will my car pass an emissions inspection with P0944?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Often reported together
Codes that owners mention in the same NHTSA complaints as P0944. They can point to a shared cause, so it's worth checking them together.
- P083BTransmission Fluid Pressure Sensor/Switch G Circuit Range/Performance4 complaints
- P0868Transmission Fluid Pressure Low4 complaints
- P1790Manufacturer-specific code3 complaints
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.