0433509 JOHNSON CONNECTION ROD ASSY.

Table 1
J1939 Code and Description Comments
3342-1
Engine Coolant Pump Differential Pressure : Low - most severe (3) The pressure drop across the water pump is lower than expected for the current engine operating conditions.
3342-18
Engine Coolant Pump Differential Pressure : Low - moderate severity (2) The pressure drop across the water pump is lower than expected for the current engine operating conditions. Probable Causes
Code
Coolant pressure sensor location
Coolant level
Hose routing
Radiator cap
Expansion tank (if equipped)
Foaming or Aeration
Leaks
Internal leaks
Water pump
Steam or hot coolant can cause severe burns.Do not loosen the filler cap or the pressure cap on a hot engine.Allow the engine to cool before removing the filler cap or the pressure cap.
Recommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Look for active codes that are associated with the system for the event code.
Codes
Result: An associated code is active.
Troubleshoot any associated codes before continuing with this test.
Result: A code is active or logged.
Proceed to Test Step 2.
2. Verify the Coolant Pressure Sensor Location
A. Turn the keyswitch to the ON position.
B. Connect Cat ET.
C. Use Cat ET to monitor the following parameters:
- Engine Coolant Pump Intake Pressure
- Engine Coolant Pressure
Less than 30 kPa (4 psi)Differential Pressure
Result: There was less than 30 kPa (4 psi) difference between the two pressure sensor readings.
Proceed to Test Step 3.
Result: There was more than 30 kPa (4 psi) difference between the two pressure sensor readings.
Repair: The coolant pressure sensor connectors are installed on the correct coolant pressure sensor. Swap the connectors for the coolant pressure sensors.
Proceed to Test Step 11.
3. Verify the Coolant Level
A. Verify that the coolant is filled to the correct level.
If the coolant level is too low, air will get into the cooling system. Air in the cooling system will cause a reduction in coolant flow and pressure.
B. Check the cooling system for coolant leaks.
Coolant Level
Result: The coolant level is correct.
Proceed to Test Step 4.
Result: The coolant level is not correct.
Repair: Determine the cause of the low coolant level. Refer to Troubleshooting, "Coolant Level Is Low" for additional information.
Proceed to Test Step 11.
4. Check the Cooling System Hose Routing
A. Check the cooling system clamps and hoses to make sure that the clamps and hoses are installed in the proper location and the clamps are tight.
B. Ensure that there are no kinks or tight bends that may cause excessive restriction.
C. Check to make sure that the hoses are routed correctly.
Leaks or Kinks
Result: The coolant clamps and hoses are installed properly.
Proceed to Test Step 5.
Result: The coolant clamps and hoses are not installed properly.
Repair: Repair or replace the damaged cooling system component.
Proceed to Test Step 11.
5. Check the Radiator Cap
A. Check the radiator cap to verify that it is holding the correct pressure on the cooling system. Refer to Test and Adjusting , "Testing the Cooling System" for additional information.
Radiator Cap
Result: The radiator cap held the correct pressure.
Proceed to Test Step 6.
Result: The radiator cap did not hold the correct pressure.
Repair: Replace the radiator cap.
Proceed to Test Step 11.
6. Check the Expansion Tank (if equipped)
A. Check the shunt line for a restriction. A restriction of the shunt line from the expansion tank to the inlet of the jacket water pump will cause a reduction of water pump efficiency.
B. Inspect the expansion tank for a restriction that blocks the port to the shunt line.
Note: The expansion tank may be integrated into the design of the radiator top tank and may not be separate.
Shunt Line
Result: The shunt line is properly installed and there are no restrictions.
Proceed to Test Step 7.
Result: The shunt line is not properly installed or there are restrictions.
Repair: Install the shunt line correctly or replace the line if necessary. Remove any restrictions that are found.
Proceed to Test Step 11.
7. Check the Coolant for Foaming or Aeration
A. Inspect the coolant for foaming or aeration. Refer to Testing and Adjusting , "Testing the Cooling System" for additional information.
Foaming or Aeration
Result: There was no foaming or aeration.
Proceed to Test Step 8.
Result: The engine coolant contains foam or aeration.
Repair: Repair the condition that is causing the foam or aeration. Refer to Testing and Adjusting , "Testing the Cooling System" for additional information.
Proceed to Test Step 11.
8. Check for a NOx reduction System (NRS) Cooler Leak
A. Check the NRS coolers for leakage. Refer to Testing and Adjusting , "Exhaust Cooler (NRS) - Test" for additional information.
NRS Coolers
Result: The NRS coolers do not leak.
Proceed to Test Step 9.
Result: An NRS cooler has a leak.
Repair: Replace the failed NRS cooler. Refer to Disassembly and Assembly manual for the related procedure.
Proceed to Test Step 11.
9. Check for Internal Coolant Leaks
A. Check the cooling system for internal coolant leaks. Refer to Testing and Adjusting , "Testing the Cooling System" for additional information.
Internal Coolant Leaks
Result: No internal coolant leaks were detected.
Proceed to Test Step 10.
Result: An internal coolant leak was detected.
Repair: Repair the cause of the internal coolant leak.
Proceed to Test Step 11.
10. Inspect the Water Pump
A. Remove the water pump and check for a damaged or loose impeller, or a restriction in the water pump inlet or outlet ports.
Damaged Impeller
Result: The water pump impeller is not damaged or loose and there are no restrictions.
Proceed to Test Step 11.
Result: The water pump impeller is damaged or loose, or there are restrictions.
Repair: Replace the water pump.
Proceed to Test Step 11.
11. Operate the Engine
A. Start the engine.
B. Run the engine until normal operating temperature has been reached.
C. Bring the engine to high idle.
Note: On certain applications, the engine speed may be limited to 1,000 RPM. The engine can be run at this speed to clear the code.
D. Operate the engine at high idle for 1 minute.
E. Connect Cat ET.
F. Use Cat ET to monitor the following:
- Codes
Code
Result: No codes are active.
Return to service.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).