- Active engine derate
- Diagnostic codes
- Event codes
- Programmable parameters
- Starting aids
- Electrical connectors
- Throttle signal
- Circuit for electronic unit injectors
- Injection actuation pressure
- Fuel supply
- Turbocharger outlet pressure sensor (intake manifold air), rated fuel position and/or FRC fuel position
- Air inlet and exhaust system
Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine speed, full load and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.
An active derate will limit engine power. If a derate is active, the "Engine Derate" will appear on any status screen on the Caterpillar Electronic Technician (ET). Determine the cause for the derate and correct the conditions that cause the derate. Verify that the set points for "Derate" that are in the programmable monitoring system have been programmed to the correct values.
Diagnostic Codes and Event Codes
Certain diagnostic codes and/or event codes may cause poor performance. Connect Cat ET and check for active codes and for logged codes. Troubleshoot any codes that are present before continuing with this procedure.
Check the following parameters on Cat ET:
- Verify that the injector codes are programmed.
- "Throttle position sensor"
- "Desired speed input configuration"
- "Direct fuel control mode"
Determine the type of throttle that is used in the application. Program the parameters to match the type of throttle that is used.
Note: If the parameters are not programmed correctly, then the engine will have poor performance.
Verify that the engine has exited cold mode. If the engine is operating in cold mode, an indicator will be displayed on the top of any of the status screens on Cat ET. Cold mode operation may slow throttle response.
Ensure that the air inlet heater is operating correctly. For additional information on the air inlet heater, refer to Troubleshooting, "Air Inlet Heater Circuit - Test".
Electrical Connections to the ECM
Check the associated wiring for damage, for abrasion, for corrosion or for incorrect attachment on the following connectors: Electronic Control Module (ECM) connectors and customer connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for additional information.
Connect Cat ET to the service tool connector. View the status for the throttle position on the status screen. Operate the throttle from the low idle position to the high idle position. The status should be 0 percent at low idle and the status should be 100 percent at high idle. If the status cannot operate in the full range, refer to Troubleshooting, "Speed Control - Test".
Circuit for the Electronic Unit Injector
Inspect the J2/P2 ECM connector and the J300/P300 unit injector connector for proper connections. Refer to Troubleshooting, " Electrical Connectors - Inspect". Connect Cat ET and cut out each cylinder in order to isolate the misfiring cylinder or cylinders. If the results are inconclusive, shut off half of the cylinders and repeat the cylinder cutout test on the active cylinders in order to locate those cylinders that are malfunctioning. Refer to Troubleshooting, "Injector Solenoid Circuit - Test".
- Check the engine oil level. Engine oil supplies the injection actuation pressure circuit. The engine oil must be kept at the proper level.
- If service has recently been performed on the engine, air may be present in the injection actuation pressure circuit. Allow the engine to fully warm up and operate the engine under load in order to ensure that the air has been purged from the injection actuation pressure circuit.
- Compare the actual actuation pressure and the desired actuation pressure on Cat ET. If these readings do not agree within 2000 kPa (290 psi), refer to Troubleshooting, "Injection Actuation Pressure Sensor - Test".
Check for a problem with the fuel supply and verify the fuel pressure. Verify that the fuel pressure sensor is installed.
- With the engine at full load, monitor "Fuel Position" and "Rated Fuel Limit" on the status screen. If "Fuel Position" does not equal "Rated Fuel Limit", then check air inlet manifold pressure.
- Verify that there are no active diagnostic codes that are associated with the turbocharger outlet pressure sensor (intake manifold air) or with the atmospheric pressure sensor.
- Monitor air inlet manifold pressure and atmospheric pressure for normal operation on the status screen.
Check the air inlet and exhaust systems for restrictions and for leaks. Look for an indication of the warning lamp or restriction indicators that are tripped if the filters are equipped with these devices. These indicators are associated with plugged filters. Replace the plugged air filters or clean the plugged air filters. Repair any leaks that are found in the system.