KIT-RELAY TERMINAL 7N7808 - 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
Engine parameters
Throttle signal
"Turbocharger outlet (boost) pressure sensor"
Atmospheric pressure sensor
Air inlet and exhaust system
Fuel supply
Cylinder performance
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. A status screen on Cat ET will display a derate if a derate is active.Cold Mode
Connect Cat ET to the service tool connector. Verify that the engine has exited cold mode.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, "Speed Control - Test"."Turbocharger Outlet (Boost) 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.
Monitor the status of "Turbocharger Outlet (Boost) Pressure" and "Atmospheric Pressure" for normal operation on Cat ET. When the engine is not running, "Turbocharger Outlet (Boost) Pressure" should be 0 kPa (0 psi).Air Inlet and Exhaust System
Check the air filter restriction indicator, if equipped. Clean plugged air filters or replace plugged air filters. Refer to the Operation and Maintenance Manual.
Check the air inlet and exhaust system for restrictions and/or leaks. Refer to Systems Operation/Testing and Adjusting.Fuel Supply
Visually check the fuel level. Do not rely on the fuel gauge only. If necessary, add fuel. 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.
Ensure that the fuel supply valve (if equipped) is in the full OPEN position.
Check the fuel lines for the following problems: restrictions, collapsed lines, pinched lines and loose connections. If problems are found with the fuel lines, repair the lines and/or replace the lines.
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.
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
Replacement of unit injectorsNote: A sight glass in the low pressure