A pressure control solenoid malfunction is an error code that occurs when the transmission control module detects an improper voltage drop in the solenoid valve. The solenoid valve is an electromechanically operated valve.
According to Engine-Codes.com, the error code for a solenoid malfunction can be caused by dirty or insufficient transmission fluid or a faulty line pressure solenoid valve. The line pressure solenoid valve harness might be opened or shortened, or it might have a poor electrical connection.
The line pressure solenoid valve regulates the oil pump discharge pressure in response to driving conditions. Usually the malfunction occurs because of debris obstructing its mechanical function. Another possible cause is limited flow of transmission fluid due to dirt or other obstruction. In this case, the fluid should be changed, and the transmission pan checked. Metal particles or excessive debris are a sign the transmission is failing and needs to be rebuilt or replaced.
According to RepairPal, an info site for drivers, symptoms of this malfunction are an illuminated check engine light, improperly shifting gears and decreased fuel economy. Additionally, the car may not be drivable. This malfunction sometimes gets misdiagnosed as a driveline problem, referred to as a performance problem, or an engine misfire.