Scheme 9
Scheme 10
Transaxle Overview
The X-Type is the first Jaguar vehicle to be installed with a transversely mounted automatic transaxle, which combines both automatic transmission and differential into one unit. The term transaxle, developed from the terms transmission and axle, is used to describe this type of arrangement.
The automatic transaxle with 5-speed lock-up provides a smooth and fast operation. The transaxle comprises a torque converter, shift solenoids, hydraulic valve body and pressure regulators. The Transmission Control Module (TCM) operates these components to control the flow of transaxle fluid, to hydraulically control, gearshift selection and shift quality.
The TCM processes the information it receives, relating to transaxle input and output speed, engine torque, transaxle fluid temperature, mode switch and gearshift selector position. This information is then used to decide which shift pattern to implement and which gear to select. Under normal conditions, shift determination is performed by monitoring the appropriate shift lines and determining the relationship of the vehicle speed and throttle opening to these lines. The shift lines are selected according to the shift pattern, present range selection and the gear position.
In the event of electrical failures the system has a failure management system to provide for a wide range of circumstances from individual signal loss to total loss of electrical power. Transaxle faults are indicated to the driver via the instrument cluster and a fail safe "limp home" mode is entered where appropriate.
Gear selection is achieved using the J-gate gearshift selector. A mode switch operated by the driver is used to select between "Normal" and "Sport" modes. In "Sport" mode the TCM will use higher engine revolutions, according to the unique shift map, than when in "Normal" mode. The status of the mode switch is indicated to the driver by the illumination of a lamp in the switch when "Sport" is selected.