Overdrive Range, Third Gear -TCC Not Applied

As the speed of the vehicle increases, the Powertrain control module (PCM) receives input signals from various engine and transmission sensors. The PCM uses this data to energize the 2-3 shift solenoid (SS) valve in order to shift the transmission into third gear at the appropriate time.

2-3 Shift Solenoid (SS) Valve (315)
De-energizes, allowing 2-3 signal fluid to exhaust through the solenoid. Spring pressure forces the 4-3 manual downshift valve (360) to move while line pressure moves the 2-3 shift valve (357) and 3-2 manual downshift valve (356).

Number 9 Ball Check Valve (372)
Located in the control valve body (300), forces 3rd fluid through a feed orifice and into the 3rd clutch passage.

Number 4 Ball Check Valve (372)
Located in the case cover (400), directs 3rd clutch fluid into the 3rd clutch/lo-1st: passage to apply the 3rd clutch.

2-3 Shift Valve (357)
When shifted, allows D4 fluid to enter the 3rd passage to stroke the 2-3 accumulator piston (136) and apply the 3rd clutch. The 2-3 shift valve also allows input clutch apply fluid to exhaust into the D3 passage and out at the manual valve (404). And provides 2-3 off signal fluid to the 1-2 shift valve.

Third Clutch
3rd clutch/lo-1st: fluid pressure applies the third clutch to shift the transmission into Third gear.

Third Roller Clutch
Holds as third clutch applies.

Input Clutch
In third gear, the input clutch is released allowing input clutch apply fluid to exhaust through the 3-4 shift valve (362) into the input clutch feed passage. At the 2-3 shift valve (357), exhausting input clutch apply fluid is directed into the D3 passage and out the manual valve (404).

Forward Band
Remains applied, but is ineffective.

1-2 Support Roller Clutch
Overruns as third clutch is applied.

2-3 Accumulator
Third clutch feed fluid is also routed to the 2-3 accumulator piston. This fluid pressure moves the piston against spring force and 2-3 accumulator feed fluid pressure. This action absorbs initial third clutch fluid pressure to cushion the third clutch apply. The movement of the 2-3 accumulator piston forces some accumulator fluid out of the accumulator.

2-3 Accumulator Valve
Excess 2-3 accumulator feed fluid is routed back to the 2-3 accumulator valve. This fluid pressure moves the accumulator valve against spring force and torque signal fluid pressure to regulate the exhaust of excess accumulator fluid. This regulation provides additional control for the third clutch apply.

Torque Converter Clutch
Torque Converter Clutch (TCC) apply could vary depending on vehicle application and may be calibrated to apply in Overdrive Range - Third Gear.

Transmission Fluid Pressure (TFP) Manual Valve Position Switch
Release fluid pressure routed to the TFP manual valve position switch signals the Powertrain Control Module (PCM) that the TCC is released.