Oil Renewal System Caterpillar

Illustration 1	g00284517
Electronic Control System

Various sensors feed engine data to the electronic control module (ECM). The ECM processes this data. The ECM sends electronic signals to the unit injector solenoids. The solenoids are energized in order to start the fuel discharge from the unit injectors. The solenoids are de-energized in order to stop the fuel discharge from the unit injectors. Refer to Systems Operation, "Electronic Unit Injector" for a complete explanation of the fuel injection process.

CAT Data Link

The engine incorporates a CAT data link. The data link is used to communicate with other devices that are based on a microprocessor.

The data link can reduce the duplication of sensors within the system by allowing controls to share information. The data link is used to communicate information about the engine to other electronic control systems. The data link is also used to interface with the electronic service tool.

Typical information about the engine or the machine that is monitored and available on the data link includes the following items.

• Air Filter Restriction

• Atmospheric Pressure

• Cold Mode Status

• Coolant Flow

• Coolant Temperature

• Crankcase Pressure

• Cylinder Output

• Diagnostic Enable Switch Status

• Diagnostic Messages

• ECM Supply Voltage

• Elevated Low Idle Enable Status

• Very Low Engine Oil Level

• Engine Identification

• Engine Speed (Actual rpm)

• Engine speed (Desired rpm)

• Engine Warning Status

• Exhaust Temperature To Turbocharger

• FRC Fuel Limit

• Fuel Filter Restriction

• Fuel Position

• Gear Status

• Ground Level Shutdown Switch Status

• High Coolant Temperature Status

• Low Oil Pressure Status

• Machine Speed

• Maximum Air Filter Restriction

• Filtered Oil Pressure

• On Signal Status

• Percent Throttle Position

• Rated Fuel Limit

• Throttle Backup/Diagnostic Enable Switch Status

• Timing Cal Enable/Status

• Total Fuel Consumption

• Turbocharger Inlet Pressure

• Turbocharger Outlet Pressure

An electronic service tool can be used to program the system configuration parameters. These parameters include the engine serial number, the machine identification, the Full Load Setting (FLS), and the Fuel Ratio Control (FRC) Offset.

When you are trying to set a parameter that requires a factory level security password, the electronic service tool will display a "Factory Password" screen. The password entry screen will display the ECM Serial Number, the Engine Serial Number, the electronic service tool Serial Number, and the total tattletales. In order to acquire these passwords, this information must be shown to an authorized Caterpillar dealer. Factory passwords are controlled by Caterpillar, Inc. The factory passwords may be obtained by authorized Caterpillar dealers.

Note: The passwords are only good for one clearing session. A different set of passwords will be needed after exiting the electronic service tool Display/Change Parameters screen.

The tool plugs into the connector for the data link in order to communicate with the ECM. The 7X-1700 Communication Adapter is installed in series between the electronic service tool and the data link connector. The communication adapter converts data that is in the language from the data link. This language is converted to a language that is used by the electronic service tool. The data link connector is located on the rear wall of the cab behind the operator's seat. The electronic service tool can also be used to display the values of all the information for diagnosing engine problems that is available on the data link in real time.

Changes in the programming that are made to the system configuration parameters are logged in the permanent memory of the ECM in order to maintain an audit of unauthorized changes. The system configuration parameters are used to customize the ECM.

Reprogramming the ECM to operate on a different application requires a different personality module and iron changes to the engine. A Caterpillar dealer should be consulted for details.

Air Filter Restriction Indication

The engine's electronic control system determines air filter restriction by calculating the pressure drop across the air filters. The calculation is performed by subtracting air pressure in the air inlet piping from atmospheric pressure. Pressures at both locations are measured by the engine's electronic control system. The maximum air inlet restriction that is recommended is 6.25 kPa (25 inches of H₂O). The maximum amount of fuel that is available will be derated. Derating will start at the filter restriction limit. Derating is performed in order to protect the engine from excessive exhaust temperatures which would result from excessive inlet air restriction. The maximum fuel is the "Rated Fuel Limit" on the electronic service tool status screen. The "Rated Fuel Limit" will decrease as the filter restriction increases beyond the allowable limit. As the air filter restriction increases beyond the maximum allowable limit, derating will increase to 20 percent.

The ECM latches the maximum air filter restriction value which has been sensed since the ECM has been powered. Any derating will be latched into the engine control system until the ECM is powered down. This will happen even though the engine may experience excessive air filter restriction only during certain operating conditions based on power demand.

The ECM will start the maximum air filter restriction derating of 20 percent if an incorrect signal from the atmospheric pressure sensor or a turbocharger inlet pressure sensor is sensed by the ECM. This will continue until the problem has been corrected.

Filter service life will vary depending on the operating environment of the engine.

Exhaust Temperatures

The engine's ECM uses the higher exhaust to turbocharger temperature sensors to provide a signal via the data link to the machine's monitoring panel. The signal will indicate whether the exhaust to turbocharger temperature is at an acceptable level. The monitoring panel warns the operator of an unacceptable exhaust to turbocharger temperature. An event will also be logged in the ECM. The event can be viewed with the electronic service tool. A factory password is required in order to clear this event with the electronic service tool.

The ECM will also derate the engine by two percent if the exhaust temperature is above the acceptable level for 30 seconds. The exhaust to turbocharger temperature must be below the acceptable level after an additional 30 seconds or the engine will be derated another two percent. Derating will continue in steps of two percent. Each step will last for 30 seconds. The steps will continue until the exhaust temperatures go below the acceptable level or the maximum derating of 20 percent is reached. The last level of derating will remain active until the ECM is powered down.

Crankcase Pressure

The ECM gets data from the crankcase pressure sensor that is mounted on the camshaft cover. The sensor provides a signal via the data link. The signal goes to the machine's monitoring panel. This will indicate when the engine's crankcase pressure is at an acceptable level. The monitoring panel will warn the operator of an unacceptable crankcase pressure. An event will also be logged in the ECM. The event can be viewed with the electronic service tool. The event can also be cleared with the electronic service tool.

Coolant Flow

The ECM uses the coolant flow switch at the outlet of the jacket water pump to provide a signal via the data link. The signal goes to the monitoring panel. This will indicate when the jacket water coolant flow is at an acceptable level. The monitoring panel will warn the operator of unacceptable coolant flow. An event will also be logged in the ECM. The event can be viewed with the electronic service tool. A factory password is required to clear the event with the electronic service tool.

Fuel Filter Restriction

The engine's ECM has a fuel filter pressure differential switch. The switch is mounted in the fuel filter housing. The switch is used to provide a signal via the data link. The signal goes to the monitoring panel. This will indicate when the engine fuel filter restriction is at an acceptable level. The monitoring panel will warn the operator when the fuel filter restriction reaches an unacceptable level. An event will also be logged in the ECM. The event can be viewed with the electronic service tool. The event can also be cleared with the electronic service tool.

Automatic Altitude Compensation

The ECM automatically compensates for engine operation at higher elevations. The electronic control system derates the fuel delivery. The fuel delivery is a function of barometric pressure. The barometric pressure is sensed by the system's atmospheric pressure sensor. Derating by the ECM begins at a specific elevation based on application. The elevation for beginning derating can be found in the TMI (Technical Marketing Information). The rate of derating is based upon atmospheric pressure. The engine is derated 1 percent power per kPa to a maximum derate of 24 percent. The derating maximum fuel delivery maintains exhaust temperatures within acceptable limits over a full range of altitudes.

Illustration 2	g00284525

If the ECM senses an incorrect signal from the atmospheric pressure sensor and the turbocharger inlet pressure sensors, the electronic control system will impose the maximum altitude derating. The maximum altitude derating will be imposed until the problem is corrected.

System Diagnostic Codes

System Event Codes