0395864 JOHNSON IMPELLER & KEY ASSY.

Table 1
Event Codes
J1939 Code and Description CDL Code and Description System Response
94-1
Engine Coolant Temperature : Low - most severe (3) E198(3)
Low Fuel Pressure The fuel pressure in the low-pressure system is below the trip point for the programmed delay time.
The code is logged.
94-17
Engine Fuel Delivery Pressure : Low - least severe (1) E198(1)
Low Fuel Pressure The fuel pressure in the low-pressure system is below the trip point for the programmed delay time.
The code is logged.
The engine power is derated.
94-18
Engine Fuel Delivery Pressure : Low - moderate severity (2) E198(2)
Low Fuel Pressure The fuel pressure in the low-pressure system is below the trip point for the programmed delay time.
The code is logged.
The engine power is derated. Probable Causes
Diagnostic codes and event codes
Fuel level
Vent port at the fuel tank
Fuel pressure sensors
Fuel pressure regulating valve
Fuel priming pump
Fuel transfer pumpRecommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Download the "Product Status Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
C. Determine if the diagnostic trouble code that directed to this procedure is present.
D. Look for active diagnostic codes that are associated with the system for the event code that directed to this procedure.
Codes
Result: An associated code is present.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: An E198 is present.
Proceed to the next step.
Result: No active codes
STOP
2. Check the Fuel Level in the Tank
A. Visually inspect the fuel level in the fuel tank. Ensure that the fuel tank contains enough fuel to operate the engine.
B. Ensure that the fuel supply valve (if equipped) is in the full OPEN position.
Fuel
level
Result: The fuel level is OK.
Proceed to the next step.
Result: The fuel level is not OK.
Fill the tank. Verify that the problem has been resolved.
If the problem is not resolved, proceed to the next step.
3. Inspect the Fuel Tank Vent Port for Debris
Vent
Result: The fuel tank vent is not plugged.
Proceed to the next step.
Result: The fuel tank vent is plugged.
Repair: Clear any restrictions with compressed air.
Do not allow debris to enter the fuel tank while you clean the cap. Damage to the fuel system will occur.
If the problem is not resolved, proceed to the next step.
4. Verify the Fuel System Is Primed
A. Drain the water from the primary filters. Refer to Operation and Maintenance Manual, "Fuel System Primary Filter (Water Separator) - Drain".
B. Verify that the fuel system is properly primed. Refer to Operation and Maintenance Manual, "Fuel System - Prime".
C. Start the engine and allow it to operate for 1 minute.
D. Check for codes.
Codes
Result: An E198 is present.
Proceed to the next step.
Result: A code other than E198 is present.
Refer to the appropriate troubleshooting story.
5. Check the Fuel Pressure Sensors
A. Start the engine. Run the engine at low idle. Use Cat ET to monitor the values for the following parameters:
- "Fuel Transfer Pump Inlet Pressure (absolute)"
- "Unfiltered Fuel Pressure (absolute)"
- "Fuel Pressure (absolute)"
B. Check the value of each parameter while the engine is at low idle. Ensure that the value for each of the parameters is reasonable.
C. Increase the engine speed from low engine idle to high engine idle while you monitor the parameters. Ensure that the value of each of the parameters fluctuates with the change in the speed of the engine. Ensure that the value of each of the sensors remains reasonable as the fuel pressure increases. Refer to Systems Operation/Testing and Adjusting for the correct pressure values.
Parameter
value
Result: All the pressures are correct.
Proceed to the next step.
Result: Not all the pressures are not correct.
Investigate and remedy the suspected pressure.
If the problem is not resolved, proceed to the next step.
6. Check the Fuel Pressure Regulating Valve
A fuel pressure regulating valve that is stuck in the open position may cause low fuel pressure. If a problem with the valve is suspected, the problem is probably caused by contamination or debris lodged between the valve and the valve seat.
A. Remove the valve assembly from the fuel filter base. Inspect the valve assembly for contamination or debris. Clean any contamination or debris that may keep the regulating valve open. If debris is present, find the source of the contamination.
B. If the fuel pressure regulating valve is the suspected cause of the low fuel pressure, replace the valve assembly.
Valve
Result: The valve was cleaned or replaced
If the problem is not resolved, proceed to the next step.
7. Check the Fuel Priming Pump
The electric fuel priming pump is used to prime the low-pressure fuel system prior to engine starting. The low-pressure fuel system must be pressurized to approximately 250 kPa (36 psi) (gauge) to open the check valves for the high-pressure pump.
A. Use Cat ET to monitor the "Fuel Pressure (absolute)" parameter during engine cranking. Ensure that the electric fuel priming pump is achieving the correct pressure. Refer to Systems Operation/Testing and Adjusting for additional information related to testing the low-pressure fuel system.
Priming
pump
pressure
Result: The pump generates the correct pressure.
Proceed to the next step.
Result: The pump did not generate the correct pressure.
Test the pump. Refer to Troubleshooting, "Fuel Priming Pump - Test".
If the problem is not resolved, proceed to the next step.
8. Check the Fuel Transfer Pump
The fuel transfer pump may not be pumping an adequate volume of fuel. If the correct pressure is not maintained during start-up the engine will start, but the engine will not continue running.
A. Use Cat ET to monitor the "Fuel Pressure (absolute)" status parameter during engine starting. Ensure that the fuel pressure is at least 250 kPa (36 psi) (gauge) during engine cranking.
B. Also ensure that the fuel pressure remains above 250 kPa (36 psi) (gauge) after the engine has started.
Transfer
pump
pressure
Result: The pump did not generate the correct pressure.
Repair: If the other fuel system components are operating within specifications, and the fuel pressure decreases after starting the engine, replace the fuel transfer pump.