C175 Petroleum Engine Caterpillar

Coolant Temperature Is High

Usage:

Use this procedure to troubleshoot high coolant temperature or use this procedure if one of the following event codes is active.

Show/hide table

Table 1
J1939 Code and Description	CDL Code and Description	Comments
110-0 Engine Coolant Temperature : High - most severe (3)	E361 (1) High Engine Coolant Temperature	The code is logged.
110-15 Engine Coolant Temperature : High - least severe (1)	E361(2) High Engine Coolant Temperature	The code is logged. Engine power is derated.
110-16 Engine Coolant Temperature : High - moderate severity (2)	E361(3) High Engine Coolant Temperature	The code is logged. If the ground speed of the vehicle is zero and the parking brake is set, the engine will be shut down.

Probable Causes

Diagnostic Codes and Event Codes
Low coolant level
Radiator
Coolant leak
Engine cooling fan
Pressure cap for the radiator
Temperature Control Module (TCM)
Jacket water pump
Engine overload

Recommended Actions

Show/hide table

Table 2
Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Connect Cat^® Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. Determine if the event code that directed to this story is present. C. Look for active diagnostic codes that are associated with the system for the event code that directed to this story.	Codes	Result: No active codes Return the unit to service. Result: An associated code is present. Repair: Troubleshoot any associated codes before continuing with this test. Result: A 110–0, 110–15, or 110–16 code is present. Proceed to Step 2.
2. Check for a Low Coolant Level	Coolant	Result: The coolant level is acceptable. Proceed to Step 3. Result: The coolant level is unacceptable. Repair: Add coolant Proceed to Step 3.
3. Inspect the Radiator A. Check the cooling fins on the radiator for dirt and/or for debris. B. Check the cooling fins on the radiator for damage. C. Check the radiator for internal blockage. Check the temperature difference between the inlet and the outlet of the radiator.	Radiator	Result: The cooling fins are clean. Continue with this step. Result: The cooling fins are not damaged. Continue with this step. Result: The cooling fins are not clean. Repair: Remove dirt and/or debris. Result: The cooling fins are damaged. Repair: Refer to the Systems Operation/Testing and Adjusting manual for instructions for testing and inspecting the cooling system. Result: The radiator has an internal blockage. Repair: Clean the radiator or perform the necessary repairs. Result: The radiator does not have an internal blockage Proceed to Step 4.
4. Check for Coolant Leaks A. Check the cooling system for leaks. - Inspect the coolant for presence of bubbles. - Check the cooling system for combustion gases.	Leak	Result: There are no apparent leaks. Proceed to Step 4. Result: There are leaks found. Repair: Repair or replace as necessary. Proceed to Step 5.
5. Inspect the Engine Cooling Fan for Proper Operation	Fan	Result: The cooling fan is operating properly. Proceed to the next step. Result: The cooling fan is not operating properly. Repair: Repair or replace as necessary. Proceed to Step 6.
6. Pressure Cap for the Radiator A. Check operation of the pressure relief valve and the radiator cap.	Relief Valve	Result: The pressure relief valve is operating properly. Proceed to Step 7. Result: The pressure relief valve is not operating properly. Repair: If necessary, clean the seal and the seating surface in the cap. Check that the seating surface on the fill neck of the radiator is clean and undamaged. If the sealing components of the pressure cap are suspect, replace the cap.
7. Temperature Control Module A. Visually inspect the wiring from the TCM to the coolant temperature sensor and from the temperature control module to the power supply. Visually inspect the 12-pin connector and the 8-pin connector at the temperature control module. Check for a tight connection at the connectors. B. Check for proper operation of the electronic fluid temperature control by following the procedure below: 1. Ensure that the keyswitch is in OFF. Turn the electrical disconnect to OFF. 2. Remove the cover bolts from the motor assembly. Remove the inspection cover from the motor. 3. Use the appropriate wrench to rotate the main shaft extension. Ensure that the shaft rotates freely. Rotate the shaft to ensure that the piston is not positioned at one of the ends stops of the valve. 4. Visually inspect the main shaft extension for rotation while turning on power to the ECM and keyswitch circuit. The shaft will rotate several times during the powering up sequence. 5. During the power-up sequence, listen for the valve to travel to the end stop. Listen for the piston to hammer the end stop to establish the valve position. 6. With the electrical disconnect in the ON position, disconnect the engine harness connector (12-pin connector) at the controller. Codes related to the valve will be activated. 7. Use a wrench to rotate the main shaft extension to position the valve piston away from the end stop of the valve. 8. Connect the connector and observe the motor assembly. The valve will repeat the power-up sequence when the engine harness (power) is connected. While you connect the connector, check the main shaft extension for rotation. The valve will hammer at the end stop. 9. Turn the electrical disconnect to OFF. Replace the inspection cover and connect all connectors. C. Disconnect the engine harness connector (12 pin) at the temperature control module. D. Measure the voltage between terminal 1 (voltage supply) and terminal 5 (return) on the harness side of the 12-pin connector at the TCM. The supply voltage for the control module must be between 18 V and 32 V. E. Restore the wiring to the original configuration.	The Connectors and Wiring, Operation of TCM, and 18 V - 32 V	Result: The connectors and wiring are not damaged. Continue with this step. Result: The connectors and/or wiring are damaged. Repair: Repair or replace as necessary. Continue with this step. Result: The TCM is operating properly. Continue with this step. Result: The TCM is not operating properly. Repair: If the piston binds during travel, disassemble and inspect the motor mount to determine the cause of the binding. Do not apply excessive force to the main shaft extension. Extensive damage to the shaft bearings may occur. Refer to Disassembly and Assembly, "Thermostatic Valve - Disassemble" for disassembly instructions. Note: The TCM may be operated in a manual mode by disconnecting the 8-pin connector for the motor assembly from the TCM. The valve may be manually positioned by using a wrench on the main shaft extension. This manual adjustment can be used to diagnose problems with other cooling system components. Disconnecting the connector for the motor assembly will not activate diagnostic codes for the TCM. Result: The supply voltage for the TCM is between 18 VDC and 32 VDC. Proceed to Step 8. Result: The supply voltage for the TCM is not between 18 VDC and 32 VDC. Repair: Repair or replace as necessary. If the problem has not been resolved, contact the Service Engineer for further instructions.
8. Inspect the Jacket Water Pump A. Inspect the impeller vanes of the water pump for damage and/or for erosion.	Damage	Result: The impeller vanes are not damaged. Proceed to Step 9. Result: The impeller vanes are damaged. Repair: Repair the impeller vanes or replace the vanes as necessary. Proceed to Step 9.
9. Check for Engine Overload A. Determine if the engine is being overloaded. B. When the engine is running in the lug condition, engine rpm does not increase with an increase of fuel. Note: The lug condition can cause high cylinder temperatures. High cylinder temperatures can cause a high coolant temperature.	Load	Result: The engine is not being overloaded. Return the unit to service. Result: The engine is being overloaded. Repair: Reduce engine load to an acceptable limit.

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).