MBE 900 ENGINE 2007 OPERATOR'S GUIDE Use Cruise Control after down shifting on a hill to pull the hill. Hitting the RSM/ACL Switch (not the Set Switch) will keep the truck accelerating in the lower gears up to the rated engine speed. cruise set speed. If your speed continues to increase, the MCM will increase the engine retarders' braking power progressively. When the vehicle returns to the set cruise speed, the engine retarders will turn off until you need them. Cruise Control will disengage below 1000 rpm or 32 kph (20 mph) road speed.
When using Cruise Control, if you want to pull the engine below 1000 rpm, remember to hold the throttle pedal to the floor to keep the engine pulling at wide-open throttle. Realistically, the engine will pull to about 1050 rpm. For safety reasons, don't use Cruise Control when it is not possible to keep the vehicle at constant speed due to: Winding roads Heavy traffic Slippery pavement Remember: The electronic data programmed into the DDEC VI system will not allow you to hurt or overfuel the engine at low or “lug” engine speeds. There is enough oil pressure to withstand hard pulls at low engine speeds. Descending grades that call for engine brake assistance.
For an explanation of the engine brake retarder system and recommendations for proper operation, refer to ENGINE BRAKE SYSTEM. Shifting Engine Brakes and Cruise Control Depending on your transmission model, the gear split may vary from 500 to 300 rpm. The electronic governor provides almost no overrun capability; and, if the transmission is downshifted too early, you will experience a temporary loss of pulling power until the engine speed falls below rated speed. If your engine is equipped with both Cruise Control and engine brake retarders, the engine retarders can operate automatically while you are in Cruise Control.
If the Cruise Control/Engine Brake function is turned ON in the MCM programming, the engine retarders will come on when your set road speed increases a few miles-per-hour (kilometers per hour) above your All information subject to change without notice. (Rev. 04/08) 53 DDC-SVC-MAN-0040 0704 Copyright © 2008 DETROIT DIESEL CORPORATION