P0778 code — how to fix error fast

If you experience the code P0778 appearing in your vehicle, it’s a clear sign that your vehicle’s vital systems are exposed to damage. Precisely, it’s one of the most common transmission-related codes and requires your immediate attention to fix it.

That’s why our team wanted to give you a complete guide on the P0778 code meaning to educate you on the main causes and consequences of dealing with this code. We’ll go through everything starting with the reasons why the code appears in the first place, and work our way to the solution from there.

Why you can trust REREV’s OBD2 code advice: Our automotive expert researchers with experienced mechanics undertakes a thorough research methodology to deliver precise insights on OBD codes. Find out more about OBD2 codes research process..

What does the P0778 code mean?

The P0778 code stands for “Pressure Control Solenoid B Electrical.” This code indicates that there is an electrical issue with the transmission control solenoid B, which controls the hydraulic pressure to the transmission.

This can lead to erratic shifting, transmission slipping, and poor vehicle performance. If left unaddressed, it can cause serious damage to the transmission. Erratic shifting and troubles shifting to a specific gear are just some of the consequences and symptoms of this code, so it’s best to deal with it right away.

What causes the P0778 code?

While this code can be rather problematic for drivers, it’s at least good that you can easily figure out what’s happening and why it appears. There are just a few common issues that are reported to be behind this code, so let’s go through each of them and explain:

Faulty transmission control solenoid B

The most common cause of the P0778 code is a faulty transmission control solenoid B. This can be due to wear and tear over time, or it could be a manufacturing defect.

If the solenoid is malfunctioning, it can’t help control the hydraulic pressure within the system that’s necessary to properly change gears, and that’s why the code appears.

Wiring issues

Another potential cause of the P0778 code is wiring issues. This can include damaged or corroded wiring, loose connections, or a short circuit in the wiring.

Faulty PCM

While a PCM defect is a rare condition, it can sometimes trigger the code. It’s one of the worst-case scenarios since a repair or replacing the module could cost upwards of $1000.

Which car models does the P0778 code affect the most?

The P0778 code can affect a variety of car models, but it’s most commonly found in vehicles with automatic transmissions, such as Honda, Acura, and Kia models. This is because these vehicles tend to have more advanced transmission systems that are more susceptible to electrical issues.

We decided to do some more digging and here are the results of our investigation on vehicles that are most exposed to the code:

• Honda Element: The P0778 code is commonly reported in Honda Element models due to a malfunctioning shift solenoid valve that can cause issues with gear shifting.
• Honda Accord: This code can also occur in Honda Accord models, where it is most often caused by a faulty shift solenoid or damaged wiring leading to the solenoid.
• Honda CR-V: In the Honda CR-V, the code is frequently associated with a failed shift solenoid, which can lead to harsh gear shifting and other transmission problems.

How to diagnose the P0778 code

Diagnosing the P0778 code can be a complex process, but there are several steps you can take to identify the cause of the problem. Here are some diagnostic methods you can use:

Use an OBD2 scanner

One of the easiest ways to diagnose the P0778 code is by using a scan tool. This tool can read the code and provide information about the specific cause of the problem.

Inspecting the wiring

Another diagnostic method is to inspect the wiring for any signs of damage or corrosion. This can be done visually or with a multimeter.

Testing the transmission control solenoid

You can also test the transmission control solenoid using a multimeter to check if it’s functioning properly.

How to fix the P0778 code

Once you’ve identified the cause of the P0778 code, you can take steps to fix the problem. Here are some potential fixes for each cause of the code:

Replace a faulty transmission control solenoid B

If the transmission control solenoid B is faulty, it will need to be replaced. This can be done by a professional mechanic or you may even be able to do it yourself, but we suggest entrusting the task to a professional.

The cost of the replacement can vary depending on the make and model of your vehicle and the location of the solenoid.

Repair wiring issues

If the issue is with the wiring, it will need to be repaired or replaced. The cost of the repair or replacement can vary depending on the extent of the damage and the location of the wiring.

Faulty PCM

Finally, you may need to replace or reprogram the PCM to deal with this issue and remove the code from your car’s onboard diagnostics system.

The cost of replacing a PCM is around $1000 to $1500 depending on your vehicle type, so we suggest that you also consider remanufactured PCMs as these are often cheaper.

How to prevent the P0778 code

Preventing the P0778 code from occurring can be done by following routine maintenance procedures. Here are some preventative measures you can take:

• Regularly change transmission fluid
• Properly maintain the transmission
• Sticking with the manufacturer’s proposed maintenance schedule

You should also check the transmission pan for debris, and ensure that all wiring and connections are secure.

Our take

In conclusion, understanding the P0778 code and how to diagnose and fix the problem can help you avoid serious transmission issues in the future.

By following routine maintenance procedures relying on the pieces of information laid out in this guide, you can ensure that your vehicle is kept safe from issues related to this code.