AutoCodes – Generic – P0778

P0778 Code - Pressure Control Solenoid 'B' Electrical

Quick Answer

The Pressure Control (PC) Solenoid Valve an electronic pressure regulator that controls transmission line pressure based on current flow through its coil windings. Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty line pressure solenoid 'B' valve. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0778 indicates Pressure Control Solenoid 'B' Electrical.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty line pressure solenoid 'B' valve.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 48,740

How popular is this code, among other codes? Medium

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jan 30, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0778 Description

The Pressure Control (PC) Solenoid Valve an electronic pressure regulator that controls transmission line pressure based on current flow through its coil windings. As current flow is increased, the magnetic field produced by the coil moves the solenoid’s plunger further away from the exhaust port. Opening the exhaust port decreases the output fluid pressure regulated by the PC solenoid valve, which ultimately decreases line pressure. The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in response to a signal sent from the Transmission Control Module (TCM).

OBDII Code P0778 - Pressure Control Solenoid 'B' Electrical - AutoCodes.com — P0778 Code - Pressure Control Solenoid 'B' Electrical

What does this mean?

What are the Possible Causes of the DTC P0778?

Low transmission fluid level
Dirty transmission fluid
Faulty line pressure solenoid 'B' valve
Line pressure solenoid 'B' valve harness is open or shorted
Line pressure solenoid 'B' valve circuit poor electrical connection

How to Fix the DTC P0778?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

When a transmission solenoid is malfunctioned, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is dirty, it's recommended to change the transmission fluid and if possible removing the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a mechanical transmission failure and that the transmission will need to be rebuilt or replaced.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0778 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Makes

P0778 Acura — Pressure Control Solenoid Valve 'B' Circuit System Fault
P0778 Audi — Pressure Control Solenoid 'B' Electrical
P0778 Chrysler — Shift Pressure Solenoid Circuit
P0778 Dodge — Shift Pressure Solenoid Circuit
P0778 Honda — Pressure Control Solenoid Valve 'B' Circuit System Fault
P0778 Infiniti — Pressure Control Solenoid 'B' Circuit
P0778 Jeep — Shift Pressure Solenoid Circuit
P0778 Lexus — Pressure Control Solenoid 'B' Electrical
P0778 Mazda — Pressure Control Solenoid 'B' Malfunction Electrical
P0778 Mitsubishi — Secondary Pressure Solenoid Valve Function Abnormal
P0778 Nissan — Pressure Control Solenoid 'B' Circuit
P0778 Saturn — Pressure Control Solenoid 'B' Electrical
P0778 Scion — Pressure Control Solenoid 'B' Electrical
P0778 Subaru — Pressure Control Solenoid 'B' Electrical
P0778 Toyota — Pressure Control Solenoid 'B' Electrical
P0778 Volkswagen — Pressure Control Solenoid 'B' Electrical

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0778 Code

1. What are common symptoms of OBDII code P0778 (Pressure Control Solenoid 'B' Electrical)?

Common symptoms include rough shifting, delayed or harsh gear changes, transmission slippage, and in some cases, the transmission may go into limp mode.

2. What are the possible causes of OBDII code P0778?

Possible causes of this code include a faulty pressure control solenoid 'B', issues with the wiring or connectors related to the solenoid, low transmission fluid levels, or a malfunctioning transmission control module.

3. How can I diagnose the cause of OBDII code P0778?

Diagnosis typically involves using a scan tool to read the code and checking the transmission fluid level and condition. Further testing may be needed to inspect the pressure control solenoid 'B', wiring, and connectors for any faults.

4. Can I drive with OBDII code P0778 present?

It is not recommended to drive with this code present, as it can lead to further damage to the transmission. It is best to address the issue promptly to prevent more severe problems.

5. How can I repair OBDII code P0778?

Repair options may include replacing the pressure control solenoid 'B', repairing or replacing any damaged wiring or connectors, ensuring proper transmission fluid levels, and resetting the trouble code.

6. Is it possible to reset OBDII code P0778 without fixing the underlying issue?

Resetting the code without addressing the underlying problem is not recommended, as the issue will likely persist and may lead to more significant transmission problems in the future.

7. Can a DIY enthusiast fix OBDII code P0778 at home?

Depending on the skill level and tools available, some DIY enthusiasts may be able to address this code at home by replacing the pressure control solenoid 'B' or checking and repairing wiring issues. However, professional diagnosis and repair are recommended for complex transmission problems.

8. How much does it cost to repair OBDII code P0778 at a mechanic?

The repair cost can vary depending on the underlying issue, labor rates in your area, and the cost of parts. On average, repairing OBDII code P0778 can range from $200 to $500 or more at a mechanic.

9. Will OBDII code P0778 cause damage to other parts of the vehicle if left unresolved?

If left unresolved, OBDII code P0778 can potentially cause damage to other components of the transmission system, leading to more extensive and expensive repairs down the line.

10. How often does OBDII code P0778 occur in vehicles?

OBDII code P0778 is not as common as some other transmission-related trouble codes, but it can still occur in vehicles with automatic transmissions, particularly in older or high-mileage vehicles.