Transmissions same gear, disengage the clutch and move the shift lever to the next lower gear. Engage the clutch smoothly. mode. If needed, a "secondary" shift mode can be pro- grammed to provide another shift configuration to opti- mize vehicle use under different operating conditions. To activate a secondary shift mode, or other special function programmed into the electronic control unit (ECU), depress the MODE button. "Mode On" is dis- played in the indicator panel just above the push but- tons. A label just above the MODE button identifies the special function. Continue downshifting, as conditions require, using the same sequence described above. IMPORTANT:
Do not rest your foot on the clutch pedal while driving. This causes partial clutch dis- engagement, which could cause premature clutch wear. NOTE: Each time a push button is depressed on the shift selector, a short beep will be heard. This indicates that the ECU has received input to change operation. NOTE: With synchronized models, disengage the clutch completely when shifting gears. Double clutching is unnecessary. If the vehicle is moving when shifting, depress the clutch pedal just far enough to disengage the clutch. The MD-series transmission system is designed to warn the driver of transmission malfunctions.
The driver of a vehicle equipped with these transmissions should know the extent of the warning system in order to safely oper- ate the vehicle. See Chapter 3 for information on the warning system. Allison Automatic Transmissions General Information Operation MD-series (MD-CR and MD-WR) automatic transmis- sions have six forward speeds and one reverse speed. See Fig. 5.3 . These transmissions have electronic shift controls that can be programmed to allow the use of different numbers of geared speeds.
For instance, the transmission can be programmed to operate as a 4-speed, 5-speed, or 6-speed unit in the "primary" shift CAUTION The engine should never be operated for more than 30 seconds at full throttle with the transmission in gear and the output stalled. Prolonged operation of 5.2