Automated Transmission Operation

Modes

The shift selection module controls the driving mode, which includes drive, manual, reverse, or low.

Drive Mode

Press the drive mode button (D) on the shift selection module to put the transmission in drive mode.

In drive mode, upshifts and downshifts are made by the transmission without driver intervention. The transmission will shift automatically when the driver presses the drive mode button (D) and depresses the accelerator pedal.

If driving conditions require, it is still possible to request a manual shift. The transmission will make the shift if the engine speed is within 75 rpm of the load-based shift point for that gear.

If the vehicle is stopped while in drive mode, the upshift/downshift buttons can be used to change the starting gear. This selection becomes the default starting gear until it is changed by the driver again, or the vehicle is shut down.

The transmission controller adapts to the working conditions of each vehicle and its driver. After power-up or a load change, it needs to learn the new conditions. While learning, it may hold a gear too long before upshifting. If this occurs, start the upshift manually. It may take three or four shifts before the transmission succeeds in learning the new load-based shift points, but after that it will handle the shifting automatically.

Automatic skip shifts may occur in drive mode if conditions are appropriate.

Manual Mode

In manual mode, upshifts and downshifts are made by the driver. This allows the driver to respond to a wide range of driving conditions, such as blind corners, tight curves, and steep hills.

To change to manual mode, press the manual mode button (MANUAL) on the shift selection module. If manual mode is selected while the vehicle is moving, the current gear will be maintained until the driver requests a shift using the proper upshift/downshift arrow button. If the manual mode is selected while the vehicle is not moving, the starting gear will be maintained until the driver requests a shift. In downhill situations in particular, the driver must be alert to vehicle speed by downshifting and/or using the service brakes as needed. A shift request will be refused if the selected gear would cause engine overspeed or excessive lugging.

To upshift, press the upshift arrow button on the shift selection module; to downshift, press the downshift arrow button. See Fig.. A shift request will be refused if the selected gear would cause engine overspeed or excessive lugging.

Reverse Mode

To put the transmission in reverse, press the reverse mode button on the shift selection module.

The UltraShift transmission has two reverse gears: reverse low and reverse high. The AutoShift transmission may have multiple reverse gears. To shift manually between the reverse gears, press the upshift or downshift arrow button until the desired reverse gear is displayed.

Reverse low is the default reverse gear. When reverse low is selected, the letter R displays on the gear indicator. See Fig.. When reverse high is selected, the letter H is displayed.

The vehicle must be moving at less than two miles per hour (3 km/h) before selecting reverse. If reverse is selected when the vehicle is moving faster, an audible alert will sound and continue sounding at three-second intervals until the vehicle slows to the proper speed or the driver selects the drive mode.

Low Mode

Low mode should be used to maximize engine braking and minimize the use of the brake pedal. It is most useful when descending steep hills or when coming to a stop. Engine speed will be increased by 200 rpm and shift points will be offset by 200 rpm.

To select low mode, press the low mode button (LOW) on the shift selection module. When in low, the current gear is maintained. Requests to upshift are not enabled.

If low mode is selected from neutral while the vehicle is stopped, the vehicle will start up in first gear and stay there until the engine approaches overspeed.

Neutral

Neutral is always available during operation, whatever the vehicle speed. When in neutral, requests to upshift or downshift are ignored. If the driver selects drive mode while the vehicle is moving in neutral, the transmission will shift into the appropriate gear given the engine speed.

When shifting from neutral, always depress the brake pedal. If the brake pedal is not depressed, the transmission will not shift and an audible alert will sound. To reset the transmission, select neutral again and attempt the shift again, this time with the brake pedal depressed.

Before shutting down the engine, return the transmission to neutral.