Need a
Repair Manual?
P0879 OBD2: Transmission Fluid Pressure Sensor/Switch "D" Circuit Intermittent

P0879 OBD2: Transmission Fluid Pressure Sensor/Switch “D” Circuit Intermittent

The P0879 code is an OBD-II trouble code that indicates a problem with the transmission fluid pressure sensor or switch “D” circuit. This code is significant as it points to potential issues within the transmission system that could affect vehicle performance.

What Does the P0879 Code Mean?

When the Transmission Control Module (TCM) detects an intermittent signal from the transmission fluid pressure sensor, it triggers the P0879 code. The TCM relies on accurate readings from the sensor to regulate transmission fluid pressure, which is vital for proper shifting and overall transmission function.

What Causes the P0879 Code?

There are several factors that can lead to the P0879 code being triggered:

  • Transmission Control Module (TCM) failure
  • Low transmission fluid level
  • Transmission fluid pressure sensor malfunction
  • Wiring issues or damaged connectors

What Are the Symptoms of the P0879 Code?

Drivers may experience various symptoms when the P0879 code is triggered, including:

  • Transmission may not shift properly
  • Increased fuel consumption

How Serious Is the P0879 Code?

The P0879 code is classified as urgent, meaning immediate action is necessary. Delaying repair can lead to severe damage to the vehicle’s transmission system, resulting in costly repairs and safety risks for drivers and passengers.

How to Diagnose the P0879 Code

Diagnosing the P0879 code involves a systematic approach:

  1. Use an OBD-II scanner to confirm the P0879 code and check for any additional trouble codes.
  2. Inspect the transmission fluid level and condition, ensuring it is at the proper level and free of contaminants.
  3. Examine the wiring and connectors associated with the transmission fluid pressure sensor for damage or corrosion.
  4. Test the transmission fluid pressure sensor using a multimeter to ensure it operates within the manufacturer specifications.
  5. Consider checking the TCM for faults if other components are functioning correctly.

Common Repairs for the P0879 Code

Repairs for the P0879 code may include:

  • Replacing the transmission fluid pressure sensor
  • Repairing or replacing damaged wiring or connectors
  • Refilling or changing transmission fluid
  • Replacing the Transmission Control Module (if necessary)

How Much Does It Cost to Fix the P0879 Code?

The cost to fix the P0879 code can vary widely based on the underlying issue. On average, repairs can range from $100 to $1,500, depending on whether a simple fluid change is needed or if more extensive repairs, such as replacing the TCM, are required.

Can I Fix the P0879 Code Myself?

While some aspects of diagnosing and fixing the P0879 code can be handled by a knowledgeable DIY mechanic, it is crucial to understand that proper diagnosis is key. Replacing components without thorough testing may lead to unnecessary repairs. If you are unsure or lack the necessary tools, it’s advisable to seek professional assistance to ensure the issue is resolved correctly.

About JC Landry

JC is the Senior Editor at eManualOnline.com, GarageSpot.com, and Drive-My.com, as well as the Webmaster of TheMechanicDoctor.com, only to name a few. He's been a certified Master Mechanic for 15 years, working for various car dealers and specialized repair shops before turning towards blogging about cars and EVs in the hope of helping the next generation of automotive technicians. He also loves cats, Johnny Cash and Subarus.

Leave a Reply

Your email address will not be published. Required fields are marked *

;