What is P0778 fault code and what does it mean? What is the description of Pressure Control Solenoid “B” Electrical Failure? How do you fix the P0778 fault code What are the symptoms and causes for the P0778 fault code
What is the P0778 Fault code? What does it all mean?
A P0778 code is issued when the powertrain controller module (PCM), detects an unusual voltage signal from either the “B” electronic pressur control solenoid or its related circuit.
The PCM monitors fluid levels using data from engine sensors. The PCM has pre-programmed pressure values that are appropriate for vehicle driving conditions. These pressure values are essential for the efficient operation of your engine. This solenoid controls the fluid pressure to allow the automatic transmission to function properly. The PCM is able to receive an electronic signal that is based on the pressure within the solenoids. Shifter bands and clutches control the automatic transmission, which provides fluid pressure at the correct place at the right moment. If code P0778 is detected by the PCM, it will trigger the alarm.
Most automatic transmissions include at least three solenoids. These are A, B, or C. Fault codes P0776 to P0777, 0577, 0778, 0778, 0779, 0778, 0778, 0778, 0779, & 0779. To identify the “B” solenoid circuit within your vehicle, consult specific repair manuals.
P0778 fault codes can be found on vehicles made by Ford, Mercury and Lincoln as well as Lexus and Toyota.
What causes the P0778 Fault code?
Here are some reasons why P0778 should be set.
- – Defective electronic pressure control solenoid “B”
- – Blockage in transmission fluid passagelines
- – Gearbox mechanical failures (torque converter, clutch, etc.)
- – Filtering and oil contamination in transmission oil
- – Transmission oil at a low level
- – Broken wires, loose connectors and open or short circuits
- – Defective transmission pump
- Defective hydraulic control device
- – Defective TCM or PCM (rarely).
What are the symptoms of P0778 Malfunction code?
These symptoms may be present in vehicles with code P0778.
- Illumination of the check engine light
- – Delay or difficulty in shifting gears
- Vehicle stuck in any gear
- – Irregular gear changes
- Transmission slippage during gear changes
- – The gearbox is overheated
- – Increased fuel consumption
- – You may experience misfire-like symptoms
- – Vehicle enters failsafe mode and allows only one gear
- – Other fault codes can be set
How to Fix the P0778 Fault Code
All electrical wiring, connectors and harnesses should be visually checked if the vehicle has been assigned code P0778. You must replace damaged or loose components. The transmission oil must be cleaned and refilled. These two actions are the most cost-effective and affordable way to repair this fault code. After clearing the codes, it is necessary to retest the vehicle. If the code comes back, it is necessary to examine the solenoid as well as any other potentially faulty components.
This is the biggest error in fixing this code. Instead of replacing the transmission high pressure pump, look for the problem in the solenoid/wiring.
There are several repairs that can resolve the P0778 fault code.
- – Replacing an electronic pressure control solenoid, or valve that is defective “B”
- Flushing blocked transmission fluid passage lines
- – Removing and replacing dirty transmission fluid.
- – Fill the transmission fluid with more
- – Repairing and replacing damaged connectors and cables
- Repair of damaged or open cables
- – Repair of mechanical gearbox faults
- Repairing a damaged transmission pump
- – Replacing a defective hydraulic control unit
- – In rare cases, replacement of TCM or PCM
How serious is the P0778 Fault code?
Fault code 0778 can cause serious problems with driveability. The vehicle cannot be operated safely and smoothly without adequate fluid pressure. Once this code has been set, it’s important to immediately intervene.
