3524B Engines for Off-Highway Trucks Caterpillar

• Cold Mode Operation

• Coolant temperature sensor

• Fuel level

• Derate mode

• Throttle signal

• Electrical connectors

• Injector

• Fuel consumption

• Air inlet restriction

• Electronic Control Module (ECM)

• Fuel supply

• CAN data link

Perform the following checks:

1. Use the Caterpillar Electronic Technician (ET) in order to verify that the engine has exited cold mode. During Cold Mode, injection timing is modified. The cylinders may cut out. Cold Mode Cylinder Cutouts may cause variations in vibration and in available power. This is normal operation.

2. Use the Cat ET in order to monitor the temperature of the coolant. If the reading is incorrect, perform the diagnostic functional test Troubleshooting, "Engine Sensor Open/Short Test".

3. Monitor fuel level during engine operation. If a low fuel level causes the problem, maintain a higher fuel level.

4. Connect the Cat ET and check for derate events. A derate status flag will appear on the Cat ET if an active engine derate is occurring. The engine speed might be limited due to one of the following possible causes: altitude, high exhaust temperatures, air filter restriction, high coolant temperature, aftercooler water temperature and crankcase pressure.

5. Use the Cat ET in order to monitor the status of the throttle. Observe the throttle position. The throttle position should be stable. The throttle position should reach 100 percent. Refer to the diagnostic functional test Troubleshooting, "Throttle Position Sensor".

6. Check for correct installation of the ECM connectors J1/P1 and J2/P2. Check for correct installation of Fuel Injector connectors J4/P4 through J19/P19. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".

7. Use the Cat ET to determine if any active diagnostic codes are present. Check that the injector trim codes have been entered. Use the Cat ET to determine if any logged diagnostic codes are present. Perform the Injector Solenoid Test. Observe that the injector solenoids are being energized on the Cat ET. Perform the Cylinder Cutout Test. Locate the misfiring cylinder. Refer to the diagnostic functional test Troubleshooting, "Injector Solenoids".

8. Use the Cat ET in order to monitor the engine status. Operate the engine under full load. Check actual fuel, max fuel and Fuel Ratio Control fuel limit (FRC). The actual fuel consumption should be equal to Max Fuel. The actual fuel consumption should be less than the FRC limit. If the actual fuel consumption is equal to Max Fuel, and the actual fuel consumption is less than the FRC limit, the electronics are operating correctly. If the readings are incorrect, refer to the diagnostic functional test Troubleshooting, "Engine Sensor Open/Short Test".

9. Check the air inlet and exhaust systems for the following problems: restrictions, collapse, pinched line and loose fittings. Repair the lines and/or replace the lines. Refer to the Testing and Adjusting manual for information on inspecting the air inlet and exhaust system for your engine.

   1. Observe the Check Engine Lamp. Check the air filter restriction indicator. Replace plugged air filters and/or clean filters. Repair any leaks.

10. If you have replaced the ECM, refer to the diagnostic procedure Troubleshooting, "Programming Parameters".

11. Check fuel lines for the following problems: restrictions, collapse, pinched line and loose fittings. Repair the lines and/or replace the lines. Refer to the Testing and Adjusting manual for information on inspecting the fuel system for your engine.

    1. Check the fuel tank for foreign objects which may block the fuel supply. Check for air in the low pressure fuel supply system after you perform the following procedures:

       • Replacing the filters

       • Working on the low pressure fuel supply circuit

       • Replacing fuel injectors

    2. Purge air from the low pressure fuel supply circuit with the hand priming pump and by cranking the engine in 30 second cycles. After you crank the engine, stop for two minutes. This will allow the starting motor to cool. Loosen the vent plug at the fuel return. The plug is located on the rear upper left side of the engine block. Hand prime the engine again if air in fuel continues. A sight glass in the low pressure supply line is helpful in diagnosing air in the fuel.

    3. Check fuel quality. In temperatures below 0 °C (32 °F), check for solidified fuel (wax). Refer to Special Publication, SEBD0717, "Diesel Fuels And Your Engine". Check the fuel pressure while the engine is cranking. Check the fuel pressure at the filter. Refer to the Testing and Adjusting manual for the correct fuel pressure for your engine. If the pressure is low, check for plugged fuel filters. If the fuel pressure is still low, check the following items: fuel transfer pump, fuel transfer pump coupling and fuel pressure regulating valve. Check for a problem with the combustion system.

12. Refer to Troubleshooting, "CAN Data Link".