KNUCKLE AS 1G2192 - Caterpillar

Table 1
Diagnostic Trouble Codes for Low Coolant Pressure
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
109-1 E2112 (3) Engine Coolant Pressure : Low - most severe (3) The engine coolant pressure is lower than expected for an extended period. The code is logged.
109-17 E2112 (1) Engine Coolant Pressure : Low - least severe (1) The engine coolant pressure is lower than expected for an extended period. The code is logged.
109-18 E2112 (2) Engine Coolant Pressure : Low - moderate severity (2) The engine coolant pressure is lower than expected for an extended period. The code is logged.
Table 2
Troubleshooting Test Steps Values Results
1. 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.
C. Check the cooling system for combustion gases.
Coolant Level
Result: The coolant level is correct.
Proceed to Test Step 2.
Result: The coolant level is not correct or combustion gases are present.
Repair: Determine the cause of the low coolant level. Refer to Troubleshooting, "Coolant Level Is Low" and Coolant Temperature Is High. Verify that the problem has been corrected.
2. Check the Cooling System Hose Routing
A. Check that the cooling system clamps and hoses are installed in the correct locations 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 3.
Result: The coolant clamps and hoses are not installed properly.
Repair: Repair or replace the damaged cooling system component. Verify that the problem has been corrected. Return the unit to service.
3. 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 4.
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.
Verify that the problem has been corrected. Return the unit to service.
4. Check the Coolant Pressure Sensor For Accuracy
A. Install a mechanical pressure gauge in the coolant jacket near the coolant pressure sensor.
B. Start the engine.
C. Connect to the engine ECM using the electronic service tool.
D. Allow the engine to run and record the pressure on the mechanical gauge.
E. Check the pressure reading at various engine speeds.
Coolant Pressure Sensor
Result: The pressure difference between the mechanical gauge and the reading on the electronic service