P0877 Code: Transmission Fluid Pressure Sensor / Switch “D” Circuit Low

The transmission fluid pressure sensor (TFPS) is a device that converts mechanical transmission pressure into an electrical signal for the powertrain control module (PCM) or transmission control module (TCM). If this electrical signal doesn’t match the range stored in the PCM or TCM’s memory, the vehicle’s computer will log a P0877 code on a scan tool.

What Does the P0877 Code Mean?

Diagnostic trouble code (DTC) P0877 stands for “Transmission Fluid Pressure Sensor / Switch ‘D’ Circuit Low.” This is a generic powertrain code that usually applies to vehicles with OBD-II.

The PCM or TCM uses the voltage signal from the TFPS to determine the transmission pressure and informs other controllers that utilize the vehicle’s data bus. A P0877 code is set when the electrical signal from the TFPS differs from the expected range of the PCM or TCM. Internal transmission problems can also cause the code to be set. The code can also be caused by mechanical issues inside the transmission.

The P0877 code shouldn’t be confused with other “D” circuit codes, such as P0875, P0876 P0878, and P0879.

Note: The definition of code P0877 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Common Causes of the P0877 Code?

• Faulty pressure sensor or switch
• Circuit issues, such as a damaged wire or poor connection
• Low fluid level
• Internal transmission failure
• Failed PCM or software in need of an update
• Failed TCM or software in need of an update

What are the Common Symptoms of the P0877 Code?

• Illuminated check engine light
• Shift quality is affected
• Transmission stuck in limp mode

How to Diagnose the P0877 Code

A P0877 code might share symptoms, causes, and affected areas with other DTCs that are related to the TFPS. You’ll have to follow the diagnostic procedures that are recommended for your specific vehicle. We recommend doing your own research before attempting any repairs on your vehicle.

If you don’t have the confidence to diagnose your vehicle, you should leave the job to a professional. They can perform the tests and repairs needed for your vehicle so that you don’t have to do them yourself.

How to Fix the P0877 Code

There are many things to consider when clearing a P0877 code. You have to take your vehicle’s make and model into account because some diagnostic and repair procedures can differ. For example, what might work to resolve a P0877 code for a GMC Acadia might not work for a Chevy Impala. Fortunately, you can find OBD-II resources online to get started on your DIY repairs.

If you’re planning to work on your vehicle, we suggest looking for technical service bulletins published by your vehicle’s manufacturer. These bulletins can include specific repair information that can help you save time. You can also get a Chilton repair manual to familiarize yourself with your vehicle’s many components. If you have extra money, you should get an ALLDATA subscription because it contains comprehensive factory information for your vehicle.