Transmission Description

Transmission Description

This transmission uses planetary gears with hydraulic electronic controls. The transmission control module (TCM) and the main control valve body units form a composite element that is installed as a single unit inside the automatic transmission.

This transmission has the following features:
^ Six forward speeds
^ Torque converter with an integral converter clutch
^ Electronic shift and pressure controls
^ Single planetary gear set
^ Double planetary gear set
^ Two fixed multi-disc clutches
^ Three multi-plate clutches

All hydraulic functions are directed by electronic solenoids to control:
^ engagement feel.
^ shift feel.
^ shift scheduling.
^ modulated torque converter clutch (TCC) applications.

This transmission has a mechatronic unit also referred to as a transmission control module (TCM) which contains:
^ Turbine shaft speed (TSS) sensor
^ Output shaft speed (OSS) sensor
^ An internal P, R, N, D selector shaft position sensor
^ Transmission fluid temperature (TFT) sensor

Engine power reaches the transmission by a torque converter with an integral converter clutch. The 6 forward gears and one reverse gear are obtained from single planetary sets.

This automatic transmission is a 6-speed electronically controlled transmission comprising the basic elements of a TCM, main control valve body unit, torque converter, one solenoid valve and 6 pressure regulators. Gear selection is achieved by the control of automatic transmission fluid flow to operate various internal clutches. The TCM operates the electrical components and provides for the control of gear selection shift pressure which increases refinement and torque converter slip.

In the event of a system fault, the TCM also provides for failure mode effect management (FMEM) to maintain maximum functional operation of the transmission with a minimum reduction in driver, passenger or vehicle safety. In the event of a total loss of control or electrical power, the basic transmission functions PARK, REVERSE, NEUTRAL and DRIVE are retained. Also 3rd or 5th gear is retained by the hydraulic system. The gear retained is dependent upon the gear selected at the time of the failure.

Automatic Transmission