How to Operate the Cruise Control

How to Operate the Cruise Control - Gen 5 DD15 - Ops - #7628

Engine speed and power are varied under cruise control to maintain the set vehicle speed. Cruise control may also be programmed to permit fast idle using the cruise control switches

Set the cruise control as follows:

  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.
Note:
Parent topic: How to Operate the Cruise Control and Fast Idle
Document Number: 0000009807
Manual Publication Date: 2024-01-03
Topic Publication Date: 2023-12-10