- Marine Engines:
- 3508 (S/N: 3PS)
- 3512 (S/N: 3RS)
- 3516 (S/N: 3SS)
- 3508B (S/N: 1TW; 2BM; 7SM)
- 3512B (S/N: 2GW; 4TN; 7HM)
- 3516B (S/N: 3CW; 8CN; 8KN)
Updated software is available for the engine Electronic Control Module (ECM) for the above listed engines. This software contains several new features and several improvements to existing strategies.
Refer to one of the cross-references for flash files that are published in the Service Information System (SIS) or the FIND system in order to determine the correct numbers for flash files that are for a particular engine. To use the FIND system, type "FLASH" in the "Search Document Types" field. Then type "3500B" in the "Key Word/Phrase" field. This search should return the following documents:
- 3500B Commercial Engine (Built > 4/97) FLASH File Cross-Reference
- 3500B Commercial Engine (Built < 4/97) FLASH File Cross-Reference
- 3500 With EUI Option Commercial Engine FLASH File Cross-Reference
- 3500B HD (High Displacement) Commercial Engine FLASH File Cross-Reference
- 3500B Machine Engine FLASH File Cross-Reference
Use the appropriate document to look up the flash file for a particular engine.
In the SIS, all the above cross-references for flash files are grouped into a single file that is called "readxref.txt". You can download this file and you can open this file with a word processor.
The cross-references for the flash files will be updated as files become available. The FIND system has the most current information. The SIS is updated periodically with information from the FIND system. Currently, the "FLASH File Part Number Progression" application in the TMI system does not provide accurate data for 3500 Engines.
SOFTWARE CHANGES
Software Changes
All of the following changes are included in the software for engines that were built after April 1997 that contain the D version of the electronics. Only the "Low Coolant Temperature Warning" change was added to the software for the engines that were built prior to April 1997 that contain the C version of the electronics. The 3.2 version or a latter version of the Cat ET is required to access some of the new parameters for this software.
Torque Limit
This new feature allows engine torque to be limited to a customer programmable value when the new feature is activated by a switch.
Two new programmable parameters were added in order to support the Torque Limiting feature. The first added parameter is the Torque Limit parameter.
| Torque Limit | ||
| Min | Default | Max |
| Torque at rated speed | Peak torque | Peak torque |
This parameter may be programmed by Cat ET to a value between peak torque and torque at rated engine speed.
The second added parameter is the Overspeed Verify Switch (OVS) - Torque Limit Switch (TLS) Select parameter.
| OVS-TLS Select | ||
| Min | Default | Max |
| "OFF (Overspeed Verify)" | "OFF (Overspeed Verify)" | "ON (Torque Limit)" |
This parameter controls the function of pin 27 of the ECM C-key connector. When pin 27 is grounded and the parameter is programmed to "OFF" the engine will trigger an overspeed shutdown event at 75% of the programmed value for overspeed shutdown. This has not changed from previous software versions. The Overspeed Verify Switch in the Electronic Instrument Panel (EIP) will still function as the switch usually functions.
When pin 27 is grounded and the parameter is programmed to "ON", the engine torque will be limited to the programmed value for the Torque Limit parameter. The switch in the EIP should be marked if that switch is being used for the torque limiting feature. This 7N-8001 Toggle Switch is a switch that makes a momentary connection. This switch should be changed to a 4D-1836 Toggle Switch if this switch is being used for torque limiting.
The same ECM switch input is used for both the Overspeed Verify feature and the Torque Limiting feature due to a shortage of ECM switch inputs. A 75% "Overspeed Verify Test" may now be initiated with Cat ET. Overspeed verification will be simplified if pin 27 is configured for the Torque Limiting feature.
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:
| 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:
| 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 the coolant temperature in order to determine if the engine is being overcooled.
The new strategy averages the load over a ten minute period. If the average load is above a customer programmable value the low coolant temperature warning is enabled. The warning will be disabled if the average load drops below the programmed set point.
The calculation that determines the average load does not begin until the engine has been operating for 10 minutes. Therefore, the monitoring of low coolant temperature will not be activated during the first 10 minutes of operation regardless of engine load.
A new parameter "Coolant Warning Engine Load Enable Threshold" has been added in order to support this feature. This new parameter will be used in forthcoming versions of Cat ET. Currently, the parameter is identified as "Load Warning Set".
| "Load Warning Set" | ||
| Min | Default | Max |
| 5 | 40 | 95 |
This set point for the percent load should be programmed to match the needs of the engine application. Ambient operating temperatures and typical load cycles of the engine should be considered when you are determining an appropriate value for this parameter.
Power Correction, Full Load Setting (FLS) and Full Torque Setting (FTS)
This programmable parameter is being added in order to adjust the fuel delivery at peak torque and rated engine speeds. This will normally be used in the factory after horsepower has been measured with a dynamometer. The programmable parameter will allow the factory to reduce the variations in the horsepower between engines.
The FLS and the FTS default to "not programmed" on a blank ECM. An active diagnostic code 268-02 is generated when the FLS or the FTS is not programmed. A factory level security password is required to change the FLS and the FTS.
The correction for the duration of the fuel injection is limited to ± 5%. This parameter should not be used to increase the fuel delivery in order to compensate for problems in the installation and/or mechanical problems with the engine .
Disable The Monitoring System When The Engine Speed Equals 0 RPM
The monitoring system is now disabled when engine speed is zero. It was previously possible for the monitoring system to activate an alarm with no engine speed. The result was nuisance alarms when the engine was not running but the electrical system was on.
Annunciation For Altitude Derate
The "!Stop" light on the module for the EMS will now flash for 15 seconds when an altitude derate is active. After 15 seconds, the light will stop flashing. Former versions of the software annunciated an altitude derate continuously.
The engine altitude derate is not affected or disabled by this change. The length of time for the annunciation of an altitude derate is the only change. Because the engines were being intentionally operated at high altitudes in the derate mode by many customers, this change to the software was made. These customers do not need to see a "!Stop" light that is continuously flashing.
Improvement To The Activation Of The General Alarm Relay
Previous versions of the software did not activate the General Alarm Relay for a low fuel level or a low coolant level. This change to the software corrects this issue.
Calibration For The Injector Trim Codes
Previous versions of the software did not check in order to ensure that the injector trim codes were entered into the calibration screen for the Cat ET. The new software checks for this condition. The new software will activate a "1495-02 Injector Trim Not Prog" diagnostic code if the injector trim codes have never been programmed.
Sea Trial Data Logger
The "Sea Trial Data Logger" feature allows each engine that is on the data link to log as many as 10 parameters. This feature is accessed from Cat ET.