1. The vehicle must be above Min Cruise Set Speed and below Max Cruise Set
Speed.
2. If the Cruise Enable Switch is left in the ON position at key OFF, the switch
must be cycled OFF before cruise control activation can take place.
3. DDEC
®
will look for a one-time activation of the clutch (if equipped) and
service brake before allowing cruise control to be enabled.
4. Turn the Cruise Enable ON.
5. Use SET/CST once the desired road speed has been achieved to lock in the
road speed.
6. The cruise control indicator will come on.
7. Use RSM/ACC to increase road speed by 1.6 kph (1.0 mph).
8. Use SET/CST to reduce road speed.
9. The service brake will disable the cruise control.
10. RSM/ACC will restores the previously set cruise speed, if the cruise control
was disabled.
• Cruise Control will maintain the set speed under normal road and load
conditions. It cannot limit vehicle speeds on downgrades if available
engine braking effort is exceeded, nor can it maintain speed on upgrades
if power requirements exceed engine power capability.
• When using cruise control after downshifting on a hill to pull the hill,
hitting the RSM/ACC Switch will keep the truck accelerating in the lower
gears up to the rated engine speed.
• Cruise Control will disengage below 1000 rpm or 32 kph (20 mph).
When using cruise control, if wanting to pull the engine below 1000 rpm,
the accelerator pedal would have to be held to the floor to keep the engine
pulling at wide-open throttle. The engine will pull down to about 1050
rpm.
How to Operate Fast Idle Using Cruise Control
Set the fast idle as follows:
1. The vehicle must be at base idle, transmission in neutral, and parking brake
set.
2. Turn the Cruise Enable ON to activate the fast idle. If the Cruise Enable
Switch is left in the ON position at key OFF, the switch must be cycled OFF
then ON.
3. The engine rpm should set to a pre-defined speed.
4. Use RSM/ACC to increase engine rpm.
5. Use SET/CST to decrease engine rpm.
6. Turning the Cruise Enable OFF, will disable the fast idle.
Gen 5 DD Platform Operators Manual
All information subject to change without notice.
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DDC-SVC-MAN-0217
Copyright © 2020 DETROIT DIESEL CORPORATION