COVER ASSEM. 5S1591 - Caterpillar

Probable Causes
Active codes and logged codes
Electrical connectors
Throttle signal
Fuel system
Fuel supply pressure
Air inlet and exhaust systemRecommended Actions
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.Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 1
Troubleshooting Test Steps Values Results
1. Active Codes and Logged Codes
A. Establish communication between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM).
B. Certain event codes may derate engine power. Monitor the diagnostic codes on Cat ET. Check for active diagnostic codes and logged codes (intermittent problems).
Note: Wait at least 30 seconds in order for diagnostic codes to become active.
Codes
Result: A code is active or logged.
Repair: Troubleshoot any codes before continuing with this procedure.
Verify that the repair eliminated the problem.
Result: A code is not active or logged.
Proceed to Test Step 2.
2. Electrical Connections
A. Verify that the following connectors are installed correctly:
- Electrical connectors for the ECM
- Connectors for the wiring harness under the valve cover
- Connectors for the engine speed/timing sensors
Electrical connectors
Result: The connectors are installed correctly.
Proceed to Test Step 3.
Result: The connectors are not installed correctly.
Repair: Install the connectors correctly. Refer toTroubleshooting, "Electrical Connectors - Inspect" for the proper troubleshooting procedure.
Verify that the repair eliminated the problem.
3. Intermittent Throttle Signal
A. Monitor the status for "Throttle Position" on Cat ET.
B. Verify that the status for "Throttle Position" is stable and that the engine is able to reach high idle speed.
Throttle signal
Result: The status for "Throttle Position" is stable.
Proceed to Test Step 4.
Result: The status for "Throttle Position" is not stable.
Repair: Make the necessary repairs. Refer to Troubleshooting, "Speed Control - Test".
Verify that the repair eliminated the problem.
4. Fuel System
A. Ensure that the fuel system is operating properly.
B. Start the engine.
C. Access the Cylinder Cutout Test in the Diagnostic Tests under the "Diagnostics" menu.
D. Select the "Automatic Cylinder Cutout Test" on Cat ET.
Cylinder cutout test
Result: The "Cylinder Cutout Test" was successful.
Proceed to Test Step 5.
Result: The "Cylinder Cutout Test" was not successful.
Repair: Repair the cylinders that failed the "Cylinder Cutout Test". Reset all active codes and clear all logged codes.
Verify that the repair eliminated the problem.
5. Fuel Supply Pressure
A.