Features and Parameters

Load Base Speed Control (LBSC) is available with ISX and ISM engines.

Default Settings

EngineISX15
400-475 hp

ISX15
485-600 hp

ISX12
Vocational
ISX12
Fuel Economy

ISX12 G

Setting

1600 rpm

2500 rpm

1800 rpm

1750 rpm

2100 rpm

When automatic transmissions are spec’d, LBSC is disabled and the transmission’s shift schedule controls the RPM range the engine operates based on vehicle speed and acceleration pedal actuation percent. For Automated Manual Transmissions, the Load Based Speed Control default values determine the RPM operating range when the transmission is in “Manual” Mode. Transmission shift schedule (calibration) prevails when in “Drive” mode.

To use the LBSC feature, the electronic parameters ‘Engine Speed Breakpoint' must be adjusted to the desired value.


Adjustment of the LBSC parameters can be accomplished with PowerSpec.

To enjoy the full benefit of Load Based Speed Control, the Cummins Road Speed Governor (RSG) and Gear Down Protection (GDP) features should also be enabled and properly set. PowerSpec incorporates a function to assist in determining optimized settings.

For 2013 ISX15 and ISX12 products:

Load Based Engine Speed Breakpoint:
Specifiy the maximum engine speed during normal conditions when operating in the lower transmission gears.

2013 Engines

Engine Break Seed Points for preferred Operational Goal

Engine

Fuel Economy

Balance

ISX15 485-600 hp

1650 RPM

1800 RPM

ISX15 400-475 hp

1500 RPM

1600 RPM

ISX12

1600 RPM

1700 RPM



For pre-EPA 2013 diesel and current natural gas platforms, LBSC requires two engine breakpoints to be set.

High Engine Speed Breakpoint
Specify the maximum engine speed during normal, but high load conditions when operating in the lower transmission gears.
Low Engine Speed Breakpoint
Specify the maximum engine speed during normal, but low load operating conditions when operating in the lower transmission gears.
*Not including vocational ratings

Gas and Pre-2013 Engines

Engine Break Seed Points for preferred Operational Goal

 

Fuel Economy

Balance

Engine

Low

High

Low

High

ISX15

1500 RPM

1600 RPM

1600 RPM

1700 RPM

ISX12

1500 RPM

1600 RPM

1600 RPM

1700 RPM

ISX12 G

1600 RPM

1800 RPM

1700 RPM

1900 RPM