HOSE AS 3667014 - Caterpillar

Diagnostics Indicate An Incorrect Signal From A Fuel Pressure Sensor
The above listed engines may log "94-02 and/or 289-02 An Incorrect Signal from a Fuel Pressure Sensor" diagnostic codes mistakenly. A previous software release disabled these diagnostics when engine speed was less than 200 RPM. The previous software release reduced the problem, but the software release did not eliminate the problem.This strategy has been improved in order to eliminate the false logging. The trip point for the diagnostic codes has been changed from 15 kPa (2 psi) differential pressure to 70 kPa (10 psi). This change will help prevent the incorrect fault logging, but this change will delay the notification of an "Incorrect Signal from a Fuel Pressure Sensor" problem until the differential pressure exceeds 70 kPa (10 psi).In addition, the absolute value of the fuel filter differential pressure is now used for display and for logging events. This change will allow the monitoring of the pressure differential, even if the sensors are incorrectly installed.A New Calculation Is Used To Determine The Value Of Percent Load Of The Engine
The calculation that is used to determine the value of percent load of the engine has been changed in order to more accurately reflect the engine load.There are two parts to the new calculation that is used to determine the value of percent load of the engine. If the engine is operated below rated speed, the percent load is calculated with the following formula:
Table 3
Percent Load =     Current Fuel (Rack Position) - Idle Fuel Position    
    Maximum Allowable Fuel Position (at this speed) - Idle Fuel Position    This change more accurately indicates percent load. The change is especially noticeable during lightly loaded conditions. If the engine is operated above rated speed, the percent load is calculated with the following formula:
Table 4
Percent Load =     Current Fuel (Rack Position) - Idle Fuel Position    
    Maximum Allowable Fuel Position (at Rated Speed) - Idle Fuel Position    This change will cause the percent load to be less than 100% load when the engine is above rated speed on the lug curve. This makes the display of percent load more useful for variable pitch propeller control.The new calculation that is used to determine the value of percent load of the engine also affects the "Load Feedback Signal ECM Output". Be sure to verify that the new strategy for the software will not adversely affect the control systems of the vessel that utilize this output before flashing the ECM with the new software.Low Coolant Temperature Warning
This feature is intended to detect an overcooling condition such as stuck open coolant temperature regulators. Events that indicated low coolant temperature were logged by previous software versions during normal engine operating conditions. This commonly occurred when the engine was lightly loaded in cold weather. This resulted in nuisance alarms.This strategy has been improved in order to reduce low coolant temperature warnings when the engine is lightly loaded. The strategy now uses the engine load and