Transmission, General information
The automatic transmission has five forward gears and one back-up (reverse) gear. The fifth gear is an overdrive which saves fuel during highway driving.
The mechanical components of the transmission are enclosed within the torque converter cover, the transmission housing and valve housing.
Gearshifts are controlled by an hydraulic operating system. Gearshifts take place without freewheeling and completely automatically in terms of load and speed.
The solenoid valves are located under the valve housing cover on the transmission, in the valve housing for the hydraulic system. These are activated by the transmission control module (TCM).
The transmission input speed sensor is electro-magnetic and acts on a toothed pulse wheel. By comparing the engine and transmission speeds, the control module can determine the amount of slippage in the torque converter.
The gear-shift position sensor has three separate functions:
- using an electrical route to inform the transmission control module (TCM) of the selected gear position
- to activate the back-up (reverse) light when the gear selector is in specified position
- To allow engine start if the gear selector is in specified. This signal is also transmitted to the engine's control system and is used for drive position compensation of idle.
The transmission and final drive share a common oil pan. A dipstick in the transmission is used to check the oil level in the transmission.