Hydraulic Systems
Hydraulic SystemsFluid Pump
The torque converter is supported in the fluid pump by a needle roller bearing. The fluid pump is driven directly from the engine by the torque converter shell and supplies transmission fluid to the transmission and the hydraulic control unit.
The fluid pump draws in transmission fluid through a filter and delivers it at high pressure to the main pressure valve in the main control valve body unit. The valve adjusts the pressure and returns excess transmission fluid to the fluid pan.
Fluid Pan, Gasket and Filter
This transmission has a unique steel pan with 2 magnets. A single use pan gasket that seals the pan to the case. All transmission fluid is drawn from the transmission fluid pan by the fluid pump and passes through the filter.
Transmission Electronic Control System
Transmission Electronic System
The transmission control module (TCM) and its input/output network control the following operations:
^ Shift timing
^ Clutch pressure (shift feel)
^ Line pressure (shift feel)
^ Torque converter clutch
In addition, the TCM receives input signals from certain transmission-related sensors. The TCM also uses these signals when determining transmission operating strategy.
Using all of these input signals, the TCM can determine when the time and conditions are right for a shift, or when to apply or release the torque converter clutch. It will also determine the pressure needed to optimize shift feel. To accomplish this, the TCM uses 6 pressure control solenoids and 1 shift solenoid to control transmission operation.
The following provides a brief description of each of the sensors and actuators used to control transmission operation.
Transmission Control Module (TCM) and Main Control Valve Body
The TCM and main control valve body are a combination of hydraulic and electronic control units. Both of these modules are installed in the transmission inside the transmission fluid pan.