P0879 Fault Code

Transmission Fluid Pressure Sensor/Switch D Circuit Intermittent

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0879 fault code refers to an issue with the Transmission Fluid Pressure Sensor/Switch D Circuit being intermittent. This means that the sensor is providing inconsistent readings or is unable to communicate properly with the vehicle's powertrain control module (PCM). This can lead to erratic transmission behavior and can affect overall vehicle performance.

What are the symptoms of the P0879 code?

Symptoms associated with the P0879 fault code may include:

• Harsh or erratic shifting
• Difficulty in shifting gears
• Transmission slipping
• Warning lights on the dashboard, such as the check engine light
• Transmission overheating.

What causes the P0879 code?

Common causes of the P0879 code include:

• Faulty Transmission Fluid Pressure Sensor
• Short circuit in the wiring of the pressure sensor
• Poor electrical connections at the sensor or the PCM
• Issues with the transmission control module (TCM)
• Low transmission fluid levels or contamination
• Internal transmission problems.

How to fix P0879?

To repair the P0879 fault code, consider the following steps:

• Inspect and, if necessary, replace the transmission fluid pressure sensor.
• Check the wiring and electrical connections for damage or corrosion. Repair or replace as needed.
• Ensure that the transmission fluid is at the proper level and is clean; replace it if contaminated.
• Run a diagnostic check to ensure that other related codes do not exist and address them accordingly.
• If all components are in good condition, consider reprogramming or replacing the TCM if it is found to be malfunctioning.