Think you have a problem with your vehicle’s transmission? You can often begin the diagnostic process by using a scan tool. If the P0777 code has been stored, then this article will help you learn about its definition and common causes and symptoms.

What Does the P0777 Code Mean?

The P0777 code is defined as Pressure Control Solenoid “B” Stuck On. The powertrain control module (PCM) stores the P0777 code when the pressure control solenoid “B” is stuck in the on position.

Pressure control solenoids are located inside the transmission and are responsible for controlling pressure within the transmission’s hydraulic circuits. Transmission fluid allows the transmission to change gears because it creates hydraulic pressure that moves the gears to their appropriate positions. The issues that store a P0777 code could result in various transmission-related symptoms.

Note: The definition of the P0777 code can 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 P0777 Code?

The issues that trigger a P0777 code can be caused by the following problems:

• Faulty pressure control solenoid
• Dirty transmission fluid
• Clogged transmission fluid filter
• Faulty transmission pump
• Faulty transmission valve body
• Blockages in transmission fluid passages
• Faulty wiring
• Faulty PCM

What are the Common Symptoms of the P0777 Code?

Most of the symptoms of the P0777 code are transmission-related. These include:

• Increased fuel consumption
• Transmission not shifting properly
• Transmission overheats
• Vehicle enters limp mode
• Illuminated check engine light

How to Diagnose the P0777 Code

While the definition of the P0777 code indicates a problem with the pressure control solenoids, this is not always guaranteed. You need to determine the main cause of this diagnostic trouble code (DTC) before you conduct any repairs. Otherwise, you might end up fixing a completely functional component.

You’ll need to thoroughly inspect the affected parts to find the problem. This job might require the use of specialized tools and knowledge. If you find this is daunting, don’t hesitate to reach out to a professional mechanic.

Do you want to learn how to diagnose a problem on your own? Watch the video below to get an idea of what the diagnostic process might involve:

How to Fix the P0777 Code

If you’re looking to fix the problems associated with the P0777 code, know that there isn’t a set procedure that will guarantee a solution. There are many ways to fix OBD-II codes because they can have underlying issues. The procedure will depend on the diagnosis. That’s why getting an accurate diagnosis is the first priority.

You should only start fixing a problem signified by an OBD code after you’ve identified the root cause. To learn about possible solutions, consult reputable internet repair resources and how-to guides. When you encounter diagnostic trouble codes, don’t forget to consult your vehicle’s repair manual.

It’s best to consult a professional mechanic if you don’t have much experience diagnosing or correcting error codes.