•  In the 5R55S transmission, fluid under line pressure moves to the solenoid feed limit valve. The solenoid feed limit valve provides fluid under a steady regulated pressure to the shift solenoids and TCC control solenoid.

•  The TCM operates the shift solenoids with on/off control. When the TCM turns off each solenoid, fluid flow is blocked. When the TCM turns on each solenoid, full fluid flow occurs.

•  The TCM operates the TCC control solenoid with varying Pulse-Width Modulation (PWM) control. This results in variable fluid flow and pressure from the TCC control solenoid to the hydraulic valve it controls.

•  In the 5R55S transmission, shift solenoid A affects the operation of the direct clutch. When shift solenoid A is on in forward speeds, the direct clutch is released. When shift solenoid A is turned off, the direct clutch is applied. shift solenoid A is also related to the operation of the intermediate band.

•  When the transmission shifter is moved to the R position under conditions that may cause transmission damage, the TCM turns off shift solenoid A to inhibit reverse operation. This affects various hydraulic control valves in order to keep the direct clutch released.

•  In the 5R55S transmission, shift solenoid B affects the operation of the intermediate band. When shift solenoid B is on, the intermediate band is applied. When shift solenoid B is turned off, the intermediate band is released. shift solenoid B is also related to the operation of the low/reverse band in manual 1st gear and manual 2nd gear.

•  The TCM does not use shift solenoid B to inhibit reverse operation in 5R55S transmission.

•  In the 5R55S transmission, shift solenoid C affects the operation of the overdrive band. When shift solenoid C is on, the overdrive band is applied. When shift solenoid C is turned off, the overdrive band is released.

•  In the 5R55S transmission, shift solenoid D affects the operation of the coast clutch. When shift solenoid D is on, the coast clutch is released. When shift solenoid D is turned off, the coast clutch is applied.

•  In the 5R55S transmission, the TCC control solenoid affects the operation of the torque converter clutch in forward speeds.

•  TCC pressure affects the positions of the converter pressure modulator valve and the converter control valve.