Descent Control and Deceleration Modes, Detroit™ Automated Transmissions

On vehicles equipped with a Detroit multifunction control (see Fig.), the functions of the lever positions for engine brake control change when cruise control is set. Two distinct modes can be activated:

• Descent Control Mode—engine braking keeps the speed below cruise set speed; throttle is not automatically applied

• Deceleration Mode—engine braking activates to reduce vehicle speed (with no lower limit) at a constant rate.

Descent Control Mode

Descent Control Mode keeps the vehicle speed below the set cruise speed on a downhill.

To activate Descent Control Mode, set the cruise control speed with the engine brake on (see Fig., positions 1, 2, or 3). In this mode, all three levels of engine braking will be employed to to keep the speed below the set cruise speed. This mode will not keep the speed above the lower limit of the set speed, so it is possible to eventually coast to a stop, unless the lever is moved to "engine brake off" (position 0), or throttle is applied. After throttle application, the Descent Control Mode is resumed.

Moving the lever to "engine brake off" (position 0) cancels Descent Control Mode and resumes cruise speed. To reactivate Descent Control Mode, reset the cruise control speed with the lever in position 1, 2, or 3.

Deceleration Mode

Deceleration Mode reduces the vehicle speed at a constant rate.

With the cruise control speed set, activate Deceleration Mode by moving the lever to engine brake on (see Fig., position 1, 2, or 3). This mode engages one of the engine brake levels, depending on the lever position. The vehicle will decelerate at a constant rate until the vehicle comes to a stop, unless throttle applied to override the deceleration, or the lever is moved to "engine brake off" (position 0).

Moving the lever to position 0 resumes the previously set cruise control speed.