PISTON 4M7910 - Caterpillar

Probable Causes
Codes
Parameters
Throttle Signal
Air Inlet and Exhaust System
Fuel System
Engine Load
Valve LashRecommended Actions
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. Engine Derate or Active Codes
A. Certain diagnostic codes and/or event codes may cause poor performance. Refer to the histogram information for engine derates in Cat ET. Check for the following histograms:
1. High Exhaust Temperature Prevention Derate Time Histogram
2. High Turbo Speed Prevention Derate Time Histogram
B. If the histograms contain derates and no diagnostic codes are present, then the engine is operating normally. The following list contains conditions that can cause derates:
1. Elevated altitude
2. Elevated inlet air temperature
3. Elevated ambient temperature
Engine Derate or Active Codes Result: A diagnostic code is present.
Troubleshoot the code and then reset the histogram.
Result: A diagnostic code is not present.
Proceed to Test Step 2.
2. Incorrect Parameters
A. Use Cat ET to verify that the correct parameters are being used. Refer to Troubleshooting, "Configuration Parameters" for additional information.
Parameters Result: The parameters are correct.
Proceed to Test Step 3.
Result: The parameters are not correct.
Input the correct parameters. Refer to Troubleshooting, "Configuration Parameters" for additional information.
3. Throttle Signal
A. Monitor the status for "Throttle Position" on Cat ET. Verify that the status for "Throttle Position" is stable and