- Diagnostic and/or event codes
- Fuel supply
- Electrical connectors
- Electrical power supply to the Electronic Control Module (ECM)
- Engine Control Switch (ECS)
- Atmospheric pressure sensor
- Turbocharger
- Air inlet and exhaust system
- Engine speed/timing sensor
- Throttle signal
- Speed/Timing sensor
Diagnostic Codes and Event Codes
Certain diagnostic codes and/or event codes may cause poor performance. Connect the Caterpillar Electronic Technician (ET) and check for active codes and logged codes.
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:
- E009 Altitude (atmospheric pressure) Derate
- E015 High Coolant Temp Derate
Troubleshoot any codes that are present before continuing with this procedure.
Check for a problem with the fuel supply and verify the fuel pressure. Verify that the fuel pressure sensor is installed. Refer to Testing and Adjusting, "Fuel System" for additional information.
Inspect the battery wires from the ECM back to the battery compartment. Refer to the Electrical System Schematic. Inspect the wires and the power relay. Check the power and ground connections to the ECM. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test" for more information.
Electrical Power Supply to the ECM
Check the power supply for the ECM. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test".
Check the operation of the engine start switch. Monitor the engine start switch on the Caterpillar Electronic Technician (ET).
Refer to Troubleshooting, "Engine Control Switch Circuit - Test".
- Turn the ECS to the STOP position and monitor the boost pressure reading on the status screen of Cat ET. The boost pressure reading should be 0 kPa (0 psi). Verify the correct operation of the atmospheric pressure sensor.
- 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, "Inspecting Electrical Connectors".
Ensure that the turbocharger is operating correctly. Periodic inspection and cleaning is recommended for the turbocharger compressor housing (inlet side).
Check the air inlet system for the following problems: restrictions, collapse and pinched line. Repair the lines and/or replace the lines.
Check for an air filter restriction indicator. Replace plugged air filters and/or clean filters. Repair any leaks.
Check the exhaust system for the following problems: restrictions, collapse and pinched line. Repair the lines and/or replace the lines.
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".
Diagnostic codes that are related to the J1939 data link will prevent correct operation of the throttle if the throttle position is transmitted over the data link. If there is a problem with the data link, the engine will remain at low idle until the data link is repaired.
Check Cat ET for any of the following logged diagnostic codes for the primary engine speed/timing sensor: 190-02, 190-03 and 190-08. If the engine is equipped with a secondary engine speed/timing sensor, check for any of the following logged diagnostic codes: 342-02, 342-03 and 342-08.
Refer to the diagnostic functional test Troubleshooting, "Engine Speed/Timing Sensor".