Features and Parameters

The ISL Cruise Control Feature is easily accessed and setup using Cummins PowerSpec. The feature interacts with various other features such as Engine Brake and Road Speed Governor. It should therefore not be programmed in isolation.

Cruise Control Enable
Choose this feature if the convenience and benefits of Cruise Control are desired.

Cruise Control Maximum Vehicle Speed
Specify the maximum vehicle speed when the Cruise Control feature is active. This parameter is used to limit vehicle speed while the Cruise Control feature is on.

Setting the Cruise Control Maximum Vehicle Speed slightly higher than the Accelerator Maximum Vehicle Speed (Road Speed Governor Maximum Speed), provides an incentive for drivers to operate in Cruise Control. This can have a positive effect on fuel consumption.

Setting it 2-4 MPH below the Accelerator Maximum Vehicle Speed will give the operator a small cushion of additional available speed that comes in handy when the accelerator pedal is used for passing situations.

The Cruise Control Maximum Vehicle Speed range is between 30 and 102 mph.

Cruise Control Auto Resume
Choose this option to allow Cruise Control to automatically resume its set speed after the operator makes a clutched gear change. This is a convenience feature and should be setup with the operator's preference in mind.

Cruise Control Save Set Speed
Choose this feature to save the most recent selected vehicle speed each time the engine is keyed off. This permits the driver to resume Cruise Control feature operation, at the vehicle speed selected prior to engine shutdown.

Cruise Control Lower Droop
During normal operation, as a vehicle negotiates a down-hill grade, the fueling required by the engine to maintain the set vehicle speed will progressively decrease. By slowing the reduction in fueling and allowing the vehicle speed to exceed the cruise control set speed limit by a small amount, the positive effects of momentum can be utilized in anticipation of the next up-hill grade. Cruise Control Lower Droop refers to the increase in speed above the set vehicle speed that the vehicle may travel in down-hill circumstances. The available Cruise Control Lower Droop range is between 0 - 3 MPH. Setting Cruise Control Lower Droop to 3 MPH will allow the vehicle to exceed the set vehicle speed by 3 MPH before limiting fueling and provide the maximum benefit that may be gained from vehicle momentum. Setting Cruise Control Lower Droop to 0 MPH will minimize the effects of momentum but will provide the best speed control during these circumstances.

Cruise Control Upper Droop
During normal operation, as the vehicle climbs an uphill grade, the Electronic Control Module will provide progressively increasing fueling to the engine in order to maintain the set vehicle speed. Continued up-hill climbing could eventually result in the maximum fueling rate being attained with little to no positive impact on vehicle speed. Cruise Control Upper Droop can minimize fuel consumed in these circumstances by automatically reducing the set vehicle speed by between 0 - 3 MPH. The time the engine spends at maximum fueling is thus reduced and fuel economy positively influenced. Setting the Upper Droop to 3 MPH will provide the best fuel economy benefit, while setting it to 0 MPH will provide maximum performance in these circumstances with no positive effect on fuel economy.

Engine Brake Cruise Control Activation
If the vehicle exceeds the Cruise Control Speed Deltas for Maximum and Minimum Engine Brake parameters and the Engine Brake switch is on, the Engine Brake will automatically be activated to slow the vehicle when this feature is enabled.

Cruise Control Speed Delta for Minimum Engine Brake
Specify the vehicle speed increase that will activate the Engine Brake Feature. This parameter is defined as the speed over Cruise Control Maximum Vehicle Speed that the vehicle will attain before the Engine Brake is activated. As vehicle speed decreases, the engine brake disengages and normal cruise control operation resumes.

When setting this speed delta, keep in mind that the maximum vehicle speed possible will include the selected Cruise Control Lower Droop. For example, a delta setting of 3 MPH for Minimum Engine Brake activation, with a Lower Droop of 2 MPH will result in the Engine Brake activating at 5 MPH above the Cruise Control Maximum Vehicle Speed. Also remember that because the Global Maximum Vehicle Speed will override any other settings, the delta should not be set in excess of this value.

The Cruise Control Speed Delta (increase above Cruise Control Maximum Vehicle Speed and Lower Droop) for Minimum Engine Brake must be set at least 1 MPH greater than the Cruise Control Lower Droop parameter.

For the Minimum Engine Brake Delta (increase above Cruise Control Maximum Vehicle Speed and Lower Droop), the range is between 1.5 mph and 10.0 mph.

Cruise Control Speed Delta for Maximum Engine Brake
Specify the vehicle speed increase that will engage maximum engine braking power. The parameters are defined as the speed over Cruise Control Maximum Vehicle Speed that the vehicle will attain before the Engine Brake is activated. As vehicle speed decreases, the engine brake disengages and normal cruise control operation resumes.

When setting the speed deltas, keep in mind that the maximum vehicle speed possible will include the selected Cruise Control Lower Droop. For example, a delta setting of 7 MPH for Maximum Engine Brake activation, with a Lower Droop of 2 MPH will result in the maximum Engine Brake engaging at 9 MPH above the Cruise Control Maximum Vehicle Speed. Also remember that because the Global Maximum Vehicle Speed will override any other settings, the deltas should not be set in access of this value.

The Cruise Control speed Delta for Maximum Engine Brake parameter must be at least 1 MPH greater than the Cruise Control Speed Delta for Minimum Engine Brake parameter.

For the Maximum Engine Brake Delta the range is between 2.5 mph and 25 mph.

Adaptive Cruise Control
The Adaptive Cruise Control feature allows an Adaptive Cruise Control system (such as the Eaton VORAD SmartCruiseTM system to override the normal vehicle cruise control set speed when the following distance behind another vehicle is reduced below the set following distance.

The Adaptive Cruise Control system sends commands to the ECM via J1939 datalink to limit engine speed and maintain a set following distance behind a vehicle traveling slower than the current cruise control set speed. The Adaptive Cruise Control system will maintain this distance as long as the vehicle in front remains there. When the vehicle in front pulls away or is no longer in the path, the vehicle equipped with Adaptive Cruise Control will slowly ramp back up to the original Cruise Control set speed.

The Adaptive Cruise Control feature cannot be enabled unless the normal Cruise Control feature is also enabled.

Feature / Parameter

Range

Default

Cruise Control Enable - Feature

Enable/Disable

Enable

Cruise Control Maximum Vehicle Speed - Parameter

30 - 102 mph

85 mph

Cruise Control Auto Resume - Feature

Enable/Disable

Disable

Cruise Control Save Set Speed - Feature

Enable/Disable

Disable

Cruise Control Lower Droop - Parameter

0 - 3 mph

2 mph

Cruise Control Upper Droop - Parameter

0 - 3 mph

0 mph

Engine Brake Cruise Control Activation - Feature

Enable/Disable

Disable

Cruise Control Speed Delta for Minimum Engine Brake - Parameter

1.5 - 10 mph

5 mph

Cruise Control Speed Delta for Maximum Engine Brake - Parameter

2.5 - 25 mph

7 mph

Adaptive Cruise Control - Feature

Enable/Disable

Disable