5th Gear Failsafe Solenoid Hydraulic Circuits
During a mechanical, hydraulic or electrical failure with the manual lever in the DRIVE position, the transmission defaults to 5th gear. When the transmission is in 5th gear failsafe, the PCM does not control the shift solenoids and they default to their normal state (maximum pressure, minimum pressure, on or off). The LPC solenoid defaults to maximum pressure, SSA defaults to minimum pressure, SSB defaults to maximum pressure, SSC defaults to minimum pressure, SSD defaults to maximum pressure and the TCC solenoid defaults to minimum pressure.
With SSB applying maximum pressure to the direct (3, 5, R) regulator and latch valves, the direct (3, 5, R) clutch is applied. With SSD applying maximum pressure to the low reverse/456 regulator and latch valves with SSE in the OFF position, the overdrive (4, 5, 6) clutch is applied, providing 5th gear.