Default Forward - 3RD Range Limp Home

Default Forward - 3rd Range Limp Home





Third Range "Limp Home" Hydraulic Schematic

If electrical power is interrupted with the transmission in third range, Solenoid C and Solenoid F (If the Torque Converter Clutch (TCC) is applied) is de-energized. Shift Valve C will move up, changing the exhaust path of C2 clutch to exhaust backfill and the exhaust path of C4 clutch to the B Trim Valve. Normally closed Trim Solenoid A continues to block the exhaust of the A trim signal pressure (trim signal remains control main). The solenoid signal pressure on top of Trim Valve A produces maximum A Trim pressure, which is routed through Shift Valve D to C3 clutch, keeping the clutch applied. With the Manual Selector in a forward position, main pressure continues to feed C1 clutch through the E Shift valve and Manual Selector Valve. The combination of C1 and C3 clutches applied keeps the transmission in third range for limp home capability If the TCC is applied, the F Solenoid de-energizes causing the F Trim valve to move up, exhausting pressure from the top of the Converter Flow Valve The Converter Flow Valve moves up, redirecting main overage to converter in and converter out to the cooler. The TCC is now released.