P0775 Diagnostic Trouble Code Pressure Control Solenoid “B” Malfunction

DTC P0775 is detected when TCM detects an improper voltage drop when it tries to operate the solenoid valve. 
The Pressure Control (PC) Solenoid Valve is an electronic pressure regulator that controls transmission line pressure based on current flow through its coil windings. When the current flow is increased the magnetic field produced by the coil moves the solenoids plunger further away from the exhaust port. Opening the exhaust port decrease the output fluid pressure regulated by the PC solenoid valve which will decrease the line pressure extremely. 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) 
 Car Trouble Symptoms 1. The Check Engine Warning Lights will be “ON”  2. There will be a Transmission shift shock. 
 Possible Cause of Problem 1. The transmission fluid level is low. 2. The transmission fluid is dirty. 3. The line pressure solenoid “B” valve is bad. 4. Line pressure solenoid “B” valve wirings are short to ground or open. 5. Line pressure solenoid “B” valve wirings connection is poor. 
What to do? If the transmission solenoid is malfunctioned, usually the problem is not the electrical part of the solenoid but rather the problem is the cause of some foreign material that obstructs the flow of transmission fluid through the transmission valve body. Check the transmission fluid condition, if the transmission fluid is dirty replace the transmission fluid. Remove the transmission pan and check if there are metal particles or debris which indicates that there is an internal problem on the transmission. Repair or replace the transmission if necessary.