Power Is Intermittently Low or Power Cutout Is Intermittent
- Diagnostic codes
- Electrical connectors
- Aftermarket engine protection devices
- Fuel supply
- Throttle position sensor
- Rack controls
- Electronic Control Module (ECM)
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| Troubleshooting Test Steps | Values | Results |
|---|---|---|
1. Check for Diagnostic Codes and/or Event Codes. A. Certain diagnostic codes and/or event codes may cause an engine shutdown. Connect Cat® Electronic Technician (ET) and check for active codes and for logged codes. |
Diagnostic and/or Event codes |
Result : There are no codes present. Proceed to Test Step 2. Result : There are diagnostic and/or event codes present. Repair : Troubleshoot any codes that are present prior to continuing with this procedure. If the problem is not resolved, proceed to Test Step 2. |
2. Check for Correct Installation of the J14/P14 Connector for the ECM. A. Thoroughly inspect the connectors for the engine speed/timing sensors. |
ECM connector |
Result : The ECM connector is OK. Proceed to Test Step 3. Result : The ECM connector is NOT OK. Repair : Refer to Troubleshooting, "Electrical Connectors - Inspect". If the problem is not resolved, proceed to Test Step 3. |
3. Inspect the Battery Wires from the ECM to the Battery Compartment. A. Inspect the wires and connectors to all circuit protection for the engine. B. Check the power and ground connections to the ECM. Check any engine shutdown switches and associated wiring. Note : Refer to the Schematic for specific wiring information. |
Battery wiring |
Result : The battery wiring is OK. Proceed to Test Step 4. Result : The battery wiring is NOT OK. Repair : Refer to Troubleshooting, "Electrical Power Supply - Test". If the problem is not resolved, proceed to Test Step 4. |
4. Check any Aftermarket Engine Protection Devices for Proper Operation. Note : These devices usually interrupt power to the ECM. |
Engine protection devices |
Result : The engine protection devices are OK. Proceed to Test Step 5. Result : The engine protection devices are NOT OK. Repair : Troubleshoot and fix any engine protection device that is causing the engine to lose power. If the problem is not resolved, proceed to Test Step 5. |
5. Visually Check the Fuel Level in the Fuel Tank. A. Do not rely on the fuel gauge only. |
Fuel level |
Result : The fuel level is OK. Proceed to Test Step 6. Result : The fuel level is NOT OK. Repair : Add fuel to the fuel tank. If the engine has been run out of fuel, it will be necessary to purge the air from the fuel system. Refer to Operation and Maintenance Manual for the correct procedure. If the problem is not resolved, proceed to Test Step 6. |
6. Check the Fuel Lines. A. Check for restrictions, collapsed lines, and pinched lines. |
Fuel lines |
Result : The fuel lines are OK. Proceed to Test Step 7. Result : The fuel lines are NOT OK. Repair : If problems are found with the fuel lines, repair the lines and/or replace the lines. If the problem is not resolved, proceed to Test Step 7. |
7. Check the Fuel Tank for Debris or Foreign Objects Which May Block the Fuel Supply. |
Fuel tank |
Result : The fuel tank is OK. Proceed to Test Step 8. Result : The fuel tank is NOT OK. Repair : Clean the fuel tank of any foreign debris. Prime the fuel system if any of the following procedures have been performed: Replacement of the fuel filters Service on the low-pressure fuel supply circuit If the problem is not resolved, proceed to Test Step 8. |
8. Check fuel quality. Note : Cold weather adversely affects the characteristics of the fuel. |
Fuel quantity |
Result : The fuel quantity is OK. Proceed to Test Step 6. Result : The fuel quantity is NOT OK. Repair : Refer to the engine Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation. If the problem is not resolved, proceed to Test Step 9. |
9. Check that the Filtered Fuel Pressure While the Engine is being Cranked. A. Refer to Systems Operation/Testing and Adjusting for the test procedure and for the correct pressure values. |
Fuel pressure |
Result : The fuel pressure is OK. Proceed to Test Step 10. Result : The fuel pressure is NOT OK. Repair : If the fuel pressure is low, replace the fuel filters. Clean the primary filter/water separator of debris. Refer to the Operation and Maintenance Manual for details. If the fuel pressure is still low, check the operation of the fuel pressure regulating valve. Also, check for the proper operation of the fuel transfer pump. Refer to Systems Operation/Testing and Adjusting for test information. If the problem is not resolved, proceed to Test Step 10. |
10. Monitor the Status for "Throttle Position" on Cat ET. A. Verify that the status for "Throttle Position" is stable and that the engine is able to reach high idle speed. |
"Throttle Position" |
Result : The "Throttle Position" is OK. Proceed to Test Step 11. Result : The "Throttle Position" is NOT OK. Repair : If a problem is suspected with the throttle, refer to the appropriate troubleshooting procedure for troubleshooting the throttle signal. If the problem is not resolved, proceed to Test Step 11. |
11. Check the Rack Solenoid for Proper Operation. |
Rack solenoid |
Result : The rack solenoid is OK. Proceed to Test Step 12. Result : The rack solenoid is NOT OK. Repair : Refer to Troubleshooting, "Fuel Rack Solenoid - Test" for troubleshooting procedures. Refer to Troubleshooting, "Fuel Control - Test" in order to troubleshoot the Dynamic Rack Controls. Refer to Troubleshooting, "Sensor Signal (Analog, Active) - Test" for procedures to troubleshoot the rack position sensor. If the problem is not resolved, proceed to Test Step 12. |
13. Check for Proper Operation of the ECM. |
ECM |
Result : The ECM is NOT OK. Repair : Refer to Troubleshooting, "ECM - Replace" for the troubleshooting procedures. Also, refer to Troubleshooting, "ECM Software - Install" |
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