C175 Tier 4 Final Engines for Off-Highway Trucks Caterpillar

Use this procedure in order to troubleshoot high coolant temperature or use this procedure if one of the following event codes is active. Refer to Troubleshooting, "Event Codes" for information about event codes. Access the engine monitoring system on Cat^® Electronic Technician (ET) in order to view the current trip points for these codes. For information on the engine monitoring system, refer to Troubleshooting, "Engine Monitoring System".

Table 1

J1939 Code and Description	CDL Code and Description	System Response
110-0 Engine Coolant Temperature : High - most severe (3)	E361(1) High Engine Coolant Temperature	The engine coolant temperature is above the trip point temperature for the programmed delay time. The code is logged.
110-15 Engine Coolant Temperature : High - least severe (1)	E361(2) High Engine Coolant Temperature	The engine coolant temperature is above the trip point temperature for the programmed delay time. The code is logged. Engine power is derated.
110-16 Engine Coolant Temperature : High - moderate severity (2)	E361(3) High Engine Coolant Temperature	The engine coolant temperature is above the trip point temperature for the programmed delay time. 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

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 event code that directed to this story is present. D. Look for active diagnostic codes that are associated with the system for the event code that directed to this story.	E361 or 4193-0	Result: An associated code is present. Repair: Troubleshoot any associated codes before continuing with this test. Result: An E361 or 4193-0 code is present. Proceed to the next step. Result: No active codes STOP
2. Low Coolant Level A. Inspect the coolant level.	Coolant	Result: The coolant level is OK. Proceed to the next step. Result: The coolant level is NOT OK. Repair: Add coolant If the problem is not resolved, proceed to the next step.
3. 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 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 cooling fins are not damaged. Continue with this step. 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 If the problem is not resolved, proceed to the next step.
4. Coolant Leak A. Check the cooling system for leaks. 1. Inspect the coolant for presence of bubbles. Note: Cavitation will reduce the efficiency of the cooling system. 2. Check the cooling system for combustion gases.	Leak	Result: The cooling system is OK. Proceed to the next step. Result: The cooling system is NOT OK. Repair: Or replace as necessary. If the problem is not resolved, proceed to the next step.
5. Engine Cooling Fan A. Check for proper operation of the cooling fan.	Fan	Result: The cooling fan is OK. Proceed to the next step. Result: The cooling fan is not OK. Repair: Repair or replace as necessary. If the problem is not resolved, proceed to the next step.
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 OK. Result: The pressure relief valve is NOT OK. 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.

Illustration 1	g01320751
Connector locations for the temperature control module (1) 8-pin connector for the motor assembly and the communications device (2) 12-pin connector for the engine harness

Illustration 2	g02554619
Removing the inspection cover from the motor assembly (3) Main shaft extension (4) Plug and O-ring seal

Illustration 3	g01321224

Table 3

Troubleshooting Test Steps	Values	Results
7. Temperature Control Module A. Perform the following procedure: 1. 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: 1. Ensure that the keyswitch is in the OFF position. Turn the electrical disconnect to the OFF position. 2. Remove cover bolts (4) 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 in order to ensure that the piston is not positioned at one of the end stops of the valve. 4. Visually inspect main shaft extension (3) for rotation while you establish power to the ECM and to the keyswitch circuit. The shaft will rotate several times during the powerup sequence. 5. During the powerup sequence, listen for the valve to travel to the end stop. Listen for the piston to hammer the end stop in order 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. Diagnostic 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 the OFF position. Replace the inspection cover and connect all connectors. C. Disconnect the engine harness connector (12 pin) at the temperature control module. D. Measure the battery voltage between terminal 1 (+Battery) 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 OK. Continue with this step. Result: The Connectors and Wiring are NOT OK. Repair: Repair or replace as necessary. Continue with this step. Result: The TCM is OK. Continue with this step. Result: The TCM is NOT OK. 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. Result: The supply voltage for the TCM is not between 18 VDC and 32 VDC. Repair: Or replace as necessary. If the problem has not been resolved, contact the Service Engineer for further instructions.
8. Jacket Water Pump 1. Inspect the impeller vanes of the water pump for damage and/or for erosion.	Damage	Result: The impeller vanes are OK. Proceed to the next step. Result: The impeller vanes are NOT OK. Repair: Impeller vanes and replace parts, if necessary. If the problem is not resolved, proceed to the next step.
9. Engine Overload A. Determine if the engine is being overloaded. NOTE: When the engine is running in the lug condition, engine rpm does not increase with an increase of fuel. 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. Result: The engine is being overloaded. Repair: Reduce engine load to an acceptable limit.