- Programmable parameters
- Diagnostic codes and event codes
- Cold mode operation and cold cylinder cutout
- Derate mode
- Throttle signal
- Electrical connectors
- Injector
- Fuel Ratio Control Limit (FRC)
- Air inlet restriction
- Exhaust restrictions
- Electronic Control Module (ECM)
- Fuel supply
- Air shutoff valve (if applicable)
Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are rated engine speed, full load and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.
Connect Caterpillar Electronic Technician (ET) and verify that the parameters are programmed correctly.
Diagnostic Codes and Event Codes
Check for active codes and/or logged codes. Troubleshoot any codes that are present before continuing with this procedure.
Cold Mode Operation and Cold Cylinder Cutout
Use the Caterpillar Electronic Technician (ET) in order to verify that the engine has exited cold mode. During cold mode, fuel injection timing is modified. When the engine is in cold mode, the cold cylinder cutout strategy may be active. The cold cylinder cutout may cause variations in vibration and available power. This is normal operation.
Connect Cat ET and check for logged derate events. A derate status flag will appear on Cat ET if an active engine derate is occurring. The engine speed might be limited due to one of the following possible causes: altitude, high exhaust temperatures, air filter restriction, high coolant temperature, aftercooler water temperature and crankcase pressure.
Use Cat ET in order to monitor the status of the throttle. Observe the throttle position. Verify that the throttle position is smooth from low idle to high idle. The throttle position should reach 100 percent at high idle.
Check for the correct installation of the ECM connector(s) J1/P1 and/or J2/P2. Check for correct installation of the applicable fuel Injector connectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Use Cat ET to determine if any active diagnostic codes are present. Check that the injector trim codes have been entered. Use Cat ET to determine if any logged diagnostic codes are present. Perform the "Injector Solenoid Test". Observe that the solenoids for the injectors are being energized on Cat ET. Perform the "Cylinder Cutout Test". Locate the misfiring cylinder. Refer to the diagnostic functional test Troubleshooting, "Injector Solenoids".
Fuel Ratio Control Limit (FRC)
Operate the engine under full load. Use Cat ET in order to monitor the following values: turbocharger compressor outlet pressure, fuel position, rated fuel position and Fuel Ratio Control (FRC). The fuel position should equal the rated fuel position. The FRC fuel position should be greater than the rated fuel position.
If any of the above values are changing rapidly for no apparent reason, there may be an intermittent problem with the wiring. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Check for an air filter restriction indicator. Replace plugged air filters and/or clean the filters. Repair any leaks.
Check the air inlet system for the following problems: restrictions, collapse, pinched line and loose fittings. Repair the lines and/or replace the lines.
Check the exhaust system for the following problems: restrictions, collapse, pinched line and loose fittings. Repair the lines and/or replace the lines.
Electronic Control Module (ECM)
If you have replaced the ECM, check the read/change system configuration parameters. Verify that the parameters match the information on the engine information plate. Verify that the correct flash file has been installed.
Check the fuel pressure after the fuel filter while the engine is being cranked. Refer to the Systems Operation/Testing and Adjusting manual for the correct pressure values. If the fuel pressure is low, replace the fuel filters. If the fuel pressure is still low, check the following items: fuel transfer pump, fuel transfer pump coupling and fuel pressure regulating valve. Refer to the Systems Operation/Testing and Adjusting manual for more information.
Air Shutoff Valve (if applicable)
Check that the air shutoff is open.