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P0944 OBD-II Trouble Code: Hydraulic Pressure Unit Loss of Pressure

check engine light

P0944 code definition

The P0944 code is defined as a loss of pressure or “prime” for the transmission’s hydraulic pump. It is most common with Dodge/Jeep vehicles, but is also used by some other manufacturers, including Volkswagen.

What the P0944 code means

If your car’s Check Engine Light comes on and the P0944 code is stored, it means that the computer has noticed a significant drop in transmission pressure and that the pump has both lost its prime and failed the prime test. The prime test is run when the transmission slips while in any forward gear, and a no pressure situation is indicated by all pressure switches.

What causes the P0944 code?

While the P0944 code indicates a loss of pressure and prime at the pump, there are a number of actual causes for the problem. These include the following:

  • Failure of the transmission pump
  • Blockage in a transmission fluid channel
  • Low transmission fluid
  • Loose transmission cooler return filter
  • Cracked or incorrectly installed transmission filter or seal
  • Main regulator valve stuck

What are the symptoms of the P0944 code?

There may be one or more symptoms experienced with the P0944 code, depending on the severity of the situation and how long it has existed. Symptoms can include:

How does a mechanic diagnose the P0944 code?

Diagnosing the P0944 code starts by connecting a handheld diagnostic scanner to the car’s computer. The mechanic will read all the codes stored in the computer. Generally, the codes will be cleared and the vehicle test driven to determine if the codes will reset.

The mechanic will also conduct a shift lever position test using a scan tool. If the shift lever position test is passed, the mechanic will move on to testing the pressure in the transmission line. This is done with a scan tool and the engine operating, with the transmission in park. Note that the transmission should be at operating temperature for this test to be accurate. Depending on the results of this test, the mechanic may also need to test the transmission line pressure in both drive and reverse using the scan tool.

The mechanic may also need to check the internal seal for signs of leakage. If there are signs of a leak, the seal will need to be replaced. If there are no signs of leakage, the pump may need to be replaced. It may also be necessary to remove the transmission fluid pan and inspect the filter for signs of damage.

Common mistakes when diagnosing the P0944 code

One of the most common mistakes with the P0944 code is not allowing the transmission to come to normal operating temperature before testing pressure. This is necessary because fluid pressures are higher when the transmission is cold, which can cause false negatives to the test.

How serious is the P0944 code?

The P0944 code is very serious, and it should be diagnosed and repaired immediately. If the problem is left unhandled, it could result in a situation in which the transmission will not engage at all, meaning that your car will not move.

What repairs can fix the P0944 code?

There are a number of possible repairs to fix the P0944 code, including the following:

Additional comments for consideration regarding the P0944 code

Transmission related problems are always serious concerns. If you’ve noticed the Check Engine Light on and transmission operation problems, it is vital to have the situation diagnosed immediately. However, note that P0944 is not used by all manufacturers, so it is possible to experience similar symptoms but not have this particular code stored in the computer.

Need help with a P0944 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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