5R55N/W/SUnderstanding Shift Solenoid Hydraulics

Shift Solenoids:In the W/S and N series transmissions, fluid under line pressure moves to the solenoid feed limit valve. The solenoid limit valve provides fluid under a steady regulated pressure to the shift solenoids and Torque Converter Clutch (TCC) solenoid.

The PCM operates the shift solenoids with ON/OFF control. When the PCM turns OFF each solenoid, fluid flow is blocked. When the PCM turns ON each solenoid, fluid flow occurs.

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

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

W/S - Shift Solenoid ASSA affects the operation of the direct clutch. When SSA is ON in forward speeds, the direct clutch is released. When SSA is turned OFF, the direct clutch is applied. SSA 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 PCM turn OFF SSA to inhibit reverse operation. This affects various hydraulic control valves in order to keep the direct clutch released.

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

N - Shift Solenoid ASSA affects the operation of the direct clutch. When SSA is ON in forward speeds, the direct clutch is released. When SSA is turned OFF, the direct clutch is applied. SSA is also related to the operation of the intermediate band.

The PCM does NOT use SSA to inhibit reverse operation in the N series transmission.

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

W/S - Shift Solenoid BSSB affects the operation of the intermediate band. When SSB is ON, the intermediate band is applied. When SSB is turned OFF, the intermediate band is released. SSB is also related to the operation of the low/reverse band in manual 1st gear and 2nd gear.

The PCM does NOT use SSB to inhibit reverse operation in W/S series transmission

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

N - Shift Solenoid BSSB affects the operation of the intermediate clutch. When SSB is ON, the intermediate clutch is applied. When SSB is turned OFF, the intermediate clutch is released. SSB is also related to the operation of the intermediate band (manual 3rd

gear) and the low/reverse band in (manual 1st gear and manual 2nd

gear).

When the transmission shifter is moved to the R position under conditions that may cause transmission damage, the PCM turns OFF SSB to inhibit reverse operation. This affects the reverse inhibit valve in order to keep the low/reverse band released

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

W/S - Shift Solenoid CSSC affects the operation of the overdrive band. When SSC is ON, the overdrive band is applied. When SSC is turned OFF, the overdrive band is released.

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

N - Shift Solenoid CSSC affects the operation of the overdrive band. When SSC is ON, the overdrive band is applied. When SSC is turned OFF, the overdrive band is released.

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

W/S - Shift Solenoid DSSD affects the operation of the coast clutch. When SSD is ON, the coast clutch is released. When SSD is turned OFF, the coast clutch is applied.

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

N - Shift Solenoid DSSD affects the operation of the coast clutch. When SSD is ON, the coast clutch is released. When SSD is turned OFF, the coast clutch is applied.

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

W/S - TCC SolenoidTCC solenoid affects the operation of the torque converter clutch in the forward speeds.

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

5R55N/W/SUnderstanding Shift Solenoid Hydraulics

N - TCC SolenoidTCC solenoid affects the operation of the torque converter clutch in forward speeds.

TCC pressure affects the positions of the converter pressure modulator valve.