Manual Second - First Gear is commanded by the TCM, when vehicle speed is low enough not to overrev the engine - calibratable in the TCM, in order to achieve maximum engine braking. Changes to the hydraulic and electrical systems are as follows:

Manual Valve: Manual Second - First Gear is commanded by the TCM only, there is no movement of the manual valve.

Low and Reverse Clutch Applied

1-2 Shift Solenoid (SS) Valve: The 1-2 SS valve is de-energized, blocking feed limit fluid from entering the 1-2 signal fluid circuit and 1-2 signal fluid pressure exhausts through the 1-2 SS valve.

1-2 Shift Control Valve: With 1-2 signal fluid exhausted, 2-3 signal fluid is able to move the 1-2 shift control valve (366) against 1-2 shift control valve spring (367) force to the applied position. This allows feed limit fluid to enter the FDL fluid circuit.

1-2 Shift Valve: FDL fluid is routed to the 1-2 shift valve (387) and moves the valve against 1-2 shift valve spring (388) force to the applied position. This allows 123 regulated fluid to enter the low and reverse clutch fluid circuit.

#8 Ball Check Valve: Low and reverse clutch fluid seats the #8 ball check valve against the reverse lockout fluid passage and enters the low and reverse clutch or reverse lockout fluid passage.

Low and Reverse Clutch: Low and reverse clutch or reverse lockout fluid pressure enters the outer area of the low and reverse clutch piston and moves the piston against spring force to apply the low and reverse clutch plates.

Second Clutch and Second Coast Clutch Release

Second Clutch Assembly: Second clutch fluid exhausts from the second clutch piston, allowing the second clutch plates to disengage.

Second Coast Clutch Assembly: Second coast clutch fluid exhausts from the second coast clutch piston, allowing the second coast clutch plates to disengage.

1-2 Shift Valve: Second coast clutch fluid is routed through the 2-3 shift valve to the 1-2 shift valve where it enters the second clutch fluid circuit. Second clutch fluid is routed through orifice #21 to the 1-2 shift valve where it exhausts.

Shift Accumulation

Second Clutch Accumulator: Second clutch fluid also exhausts from the second clutch accumulator assembly. Accumulator fluid moves the second clutch accumulator piston against accumulator spring force in preparation for another application of the second clutch.

Manual Second - First Gear