How to fix a P0776 Code: Pressure Control Solenoid B Performance or Stuck Off.
A P0776 Code is set when the computer sees the transmission pressure control solenoid “B” is not working.
Fixing a transmission can be difficult since there are often many small components.
Be sure to get a diagram for your specific transmission to know where all the solenoids are located.
Having the transmission fluid changed on a high-mileage transmission that has never been maintained can sometimes cause issues.

Possible Causes of a P0776 Code:
Low or Dirty Transmission Fluid
Bad Pressure Control Solenoid “B”
Wiring (Open/Short)
Faulty Transmission (Bad Valve Body or other Mechanical Issues)
Faulty Computer (PCM/TCM)

By using this information user assumes all risk of use.