V-BELT 1252948 - Caterpillar

Note: If this fault occurs only under load, refer to Troubleshooting, "Acceleration Is Poor or Throttle Response Is Poor".Probable Causes
Diagnostic codes
Event codes
Derates
Cold mode and/or starting aids
Engine parameters
Throttle signal
Decelerator pedal
Intake manifold pressure sensor and atmospheric pressure sensor
Air inlet and exhaust system
Fuel supply
Cylinder performance
Electrical connectors
Accessory equipmentRecommended Actions
Diagnostic Codes, Event Codes and Derates
Certain diagnostic codes, event codes and/or derates may cause poor performance. Connect Caterpillar Electronic Technician (ET) and check for active codes and/or for logged codes. Troubleshoot any codes that are present before continuing with this procedure.If this application supports engine derates, use Cat ET to check for logged derates. Refer to Troubleshooting, "Event Code List" for the specific events that are applicable to this application. A status screen on Cat ET will display a derate if a derate is active.Cold Mode and/or Starting Aids
Connect Cat ET to the service tool connector. Verify that the engine has exited cold mode. This may limit engine speed.Check the operation of the air inlet heater (if applicable). Ensure that the air inlet heater is operating properly. For additional information on troubleshooting electrical problems with the air inlet heater, refer to Troubleshooting, "Air Inlet Heater - Test".Check the operation of the ether injection system (if applicable). Ensure that the ether injection system is operating properly. For additional information on troubleshooting electrical problems with the ether injection system, refer to ON position. For additional information, refer to Troubleshooting, "Ether Starting Aid - Test".Engine Parameters
Verify that the correct engine parameters are being used.Throttle Signal
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 can not operate in the full range, refer to Troubleshooting, "Throttle Position Sensor - Calibrate".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.Decelerator Pedal
Monitor the decelerator pedal on Cat ET. Verify that the decelerator pedal is operating properly.Intake Manifold Pressure Sensor and Atmospheric Pressure Sensor
Monitor the status of "Fuel Position", of "Rated Fuel Limit", and of "FRC Fuel Limit" on Cat ET while the engine is operating under full load. These parameters must reflect the information below.
Table 1
"Fuel Position" = "Rated Fuel Limit"
and
"Fuel Position" < "FRC Fuel Limit"    If "Fuel Position" equals "Rated Fuel Limit" and "Fuel Position" is less than "FRC Fuel Limit", the electronics are operating correctly. Otherwise, proceed with the next Step.
Use Cat ET in order to monitor the status of the "Boost Pressure". With the engine stopped, the correct "Boost Pressure" is 0 kPa (0 psi).
Start the engine and monitor the status of "Boost Pressure" while you vary the engine speed. Ensure that the