What does it mean?
In the modern automatic transmission, hydraulic pressure is generated in the pump, usually located at the front of the transmission, driven by the engine via the torque converter housing. Channels direct automatic transmission fluid to the valve body, which contains the shift solenoid (SS) valves and pressure control solenoid (PCS) valves. The transmission control module (TCM) controls the activation and modulation of the various solenoid valves, depending on driver demand and driving conditions.
The TCM may or may not be integrated into the ECM (engine control module). Electronically-controlled valves are used to shift and maintain gears. The SS valves control the activation and deactivation of clutches, brakes, and bands inside the transmission, effecting the engagement and disengagement of whatever gear is desired or required by the driver and operating conditions.
One or more PCS valves control hydraulic pressure inside the transmission, which can affect how shift engagements occur, whether slow and soft or hard and fast. If the TCM detects a problem with one of the valves, such as an open circuit, it commands the malfunction indicator lamp (MIL) “On” and stores a diagnostic trouble code (DTC) in system memory. DTC P0968 is defined as “Pressure Control Solenoid ‘C’ Control Circuit Open,” though different automakers may have slightly different definitions.
Note: Open Circuit means that a component or sensor in a system is deprived of the reference voltage it needs to work. Causes of open circuits are many and varied, but for the most part, this type of code is caused by broken wiring, poor connections across electrical connectors or previously repaired wiring, loss of ground that prevents current flow, blown fuses, defective relays, faulty switches, or any of a host of other issues and problems that prevents the flow of current through wiring.