DRIVE GP-FAN 4725049 - Caterpillar

Probable Causes
Diagnostic codes
Parameters in the Electronic Control Module (ECM)
Throttle Position Sensor/Throttle Switches
Air intake and exhaust system
Valve lash
Turbocharger
Fuel supply
Low compression (cylinder pressure)
Electronic unit injectors
Individual malfunctioning cylinderRecommended Actions
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
Note: The procedures have been listed in order of probability. Complete the procedures in order.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.
Table 1
Troubleshooting Test Steps Values Results
1. Diagnostic Codes
Note: Certain diagnostic codes may cause poor performance.
A. Use the electronic service tool to check for active or logged diagnostic codes.
Engine Derate or Diagnostic Codes
Result: A diagnostic code is present.
Repair: Troubleshoot the diagnostic code. Refer to Troubleshooting, "Diagnostic Trouble Codes".
Result: A diagnostic code is not present.
Proceed to Test Step 2.
2. Parameters in the Electronic Control Module (ECM)
A. Use the electronic service tool to verify that the correct parameters are being used. Refer to Troubleshooting, "Configuration Parameters" for additional information.
Parameters
Result: The parameters are not correct.
Repair: Input the correct parameters. Refer to Troubleshooting, "Configuration Parameters" for additional information.
Result: The parameters are correct.
Proceed to Test Step 3.
3. Throttle Position Sensor/Throttle Switches
A. Turn the start switch to the ON position.
B. Run the engine until the speed is equal to the maximum no-load speed.
C. Use the electronic service tool to make sure that the throttle is set to reach the maximum no-load speed.
Electrical connections
Result: The throttle response is not as expected.
Repair: If the maximum no-load speed cannot be obtained refer to Troubleshooting, "Switch Circuits - Test (Throttle Switch)" and Troubleshooting, "Mode Selection - Test".
If the engine speed is erratic refer to Troubleshooting, "Speed Control - Test".
Result: All responses are normal.
Proceed to Test Step 4.
4. Air Intake and Exhaust System
A. Observe the engine warning lamp. Check for an air filter restriction indicator, if equipped. Replace plugged air filters. Refer to the Operation and Maintenance Manual.
B. Check the air inlet and exhaust system for restrictions and/or leaks. Refer to Systems Operation/Testing and Adjusting, "Air Inlet and Exhaust System - Inspect".
Restrictions
Result: There are restrictions in the air inlet or exhaust system.
Repair: Make the necessary repairs, Refer to Systems Operation/Testing and Adjusting, "Air Inlet and Exhaust System - Inspect" for additional information.
Result: There are no restrictions in the air inlet or exhaust system.
Proceed to Test Step 5.
5. Valve Lash
Note: The valve lash can affect the performance of the engine.
A. Check the valve lash. Refer to Systems Operation, Testing and Adjusting, "Engine Valve Lash - Inspect".
Valve lash
Result: The valve lash is not correct.
Repair: Make any necessary repairs. Refer to Systems Operation, Testing and Adjusting, "Engine Valve Lash - Inspect".
Result: The valve lash is correct.
Proceed to Test Step 6.
7. Turbocharger
Note: The turbocharger that is installed on the engine is a nonserviceable item. If any mechanical fault exists, then the faulty turbocharger must be replaced.
A. Ensure that the mounting bolts for the