C175 Tier 4 Final Engines for Off-Highway Trucks Caterpillar

Coolant Temperature Control Module - Test

Usage:

793F D3T

Use this procedure to troubleshoot the coolant Temperature Control Module (TCM). Also, use this procedure if the following codes are active or logged.

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Table 1
J1939 Code and Description	CDL Code and Description	Comments
4193–19 Engine Coolant Pump Outlet Temperature : Data Error	2349–19 Engine Coolant Pump Outlet Temperature : Data Error	The coolant temperature control module reported that there is a problem with the circuit for the coolant temperature sensor. The problem is communicated to the Electronic Control Module (ECM) via the CAN data link.
4193–9 Engine Coolant Pump Outlet Temperature : Abnormal Update Rate	2854–9 Coolant Temperature Control Module : Abnormal Update Rate	The TCM cannot communicate with the engine ECM.
4193–14 Engine Coolant Pump Outlet Temperature : Special Instruction	2854–14 Coolant Temperature Control Module : Special Instruction	At startup, the ECM detected a mismatch between the engine software and the TCM hardware.

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Illustration 1	g06055398

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Table 2
Troubleshooting Test Steps	Value	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 even code.	Codes	Result: A -9 code is present Proceed to Test Step 8. Result: A -14 code is present. Proceed to Test Step 5. Result: A -19 code is present. Proceed to Test Step 2.
2. Check for Opens in the Engine Coolant Pump Outlet Temperature Sensor Wiring Harness A. Turn the keyswitch to OFF. B. Disconnect the Engine Coolant Pump Outlet Temperature Sensor wiring harness from the sensor. C. Disconnect the wiring harness connector from the Coolant Temperature Control Module. D. Measure the resistance between terminal 28 on the Coolant Temperature Control Module connector and terminal 1 on the Coolant Pump Outlet Temperature Sensor connector. E. Measure the resistance between terminal 3 on the Coolant Temperature Control Module connector and terminal 2 on the Coolant Pump Outlet Temperature Sensor connector.	Open Circuit	Result: There was less than 10Ω of resistance between the Engine Coolant Pump Outlet Temperature Sensor circuit wires. Proceed to Test Step 3. Result: There was more than 10Ω of resistance on one of the Engine Coolant Pump Outlet Temperatures Sensor circuit wires. Repair: There is an open in the wiring harness. Repair the wiring or replace the harness. Proceed to Test Step 10.
3. Check for Short Circuits in the Engine Coolant Pump Outlet Temperature Sensor Wiring Harness A. Turn the keyswitch to OFF. B. Disconnect the Engine Coolant Pump Outlet Temperature Sensor wiring harness from the sensor. C. Disconnect the wiring harness connector from the Coolant Temperature Control Module. D. Measure the resistance between terminal 28 on the Coolant Temperature Control Module connector and a known good chassis ground. E. Measure the resistance between terminal 34 on the Coolant Temperature Control Module connector and a known good chassis ground.	Short Circuit	Result: There are more than 100KΩ of resistance between the connector terminal and ground on both the Engine Coolant Pump Outlet Temperature Sensor circuit wires. Proceed to Test Step 4. Result: There was less than 100KΩ resistance between the connector terminal and ground on one of the Engine Coolant Pump Outlet Temperatures Sensor circuit wires. Repair: There is a short circuit to ground in the wiring harness. Repair the wiring or replace the harness. Proceed to Test Step 10.
4. Check for Short Circuits in the Engine Coolant Pump Outlet Temperature Sensor Wiring Harness A. Turn the keyswitch to OFF. B. Disconnect the Engine Coolant Pump Outlet Temperature Sensor wiring harness from the sensor. C. Disconnect the wiring harness connector from the Coolant Temperature Control Module. D. Measure the resistance between terminal 28 of the Coolant Temperature Control Module connector and all other pins in the Coolant Temperature Control Module connector. E. Measure the resistance between terminal 34 of the Coolant Temperature Control Module connector and all other pins in the Coolant Temperature Control Module connector.	Short Circuit	Result: There was more than 100KΩ of resistance between all the Engine Coolant Pump Outlet Temperature Sensor circuit wires. Repair: A failed Engine Coolant Pump Outlet Temperature Sensor has been detected. Replace the Engine Coolant Pump Outlet Temperature Sensor. Proceed to Test Step 10. Result: There was less than 100KΩ of resistance between all the Engine Coolant Pump Outlet Temperature Sensor circuit wires. Repair: There is a pin to pin short circuit in the harness. Repair the wiring or replace the harness. Proceed to Test Step 10 .
5. Check the Part Number of the Component A. Locate the part number of the component that was identified by the "System Communication Status". Check to see if the part number is correct for the application.	Part number	Result: The part is correct for the application. Proceed to Test Step 6. Result: The part is not correct for the application. Repair: Replace the component with the correct part number. Proceed to Test Step 10.
6. Check for Incorrect Configuration Parameters A. Connect Cat ET. B. Use Cat ET to verify that the correct parameters are being used.	Configuration parameters	Result: The parameters are OK. Proceed to Test Step 7. Result: The parameters are NOT OK. Repair: Input the correct parameters. Refer to Troubleshooting, Configuration Parameters for additional information. If the problem is not resolved, proceed to Test Step 7.
7. Check that the Latest Flash File Software is Installed on the ECM A. Connect Cat ET. B. Use Cat ET to verify that the correct flash file is being used.	Flash file	Result: The flash file is OK. Proceed to Test Step 10. Result: The flash file is NOT OK. Repair: Perform the following procedure: 1. Download the latest flash file from SIS Web. 2. Install the software onto the ECM. Refer to Troubleshooting, ECM Software - Install for more information. Proceed to Test Step 10.
8. Check the resistance of the Data Link A. Turn the keyswitch to OFF. B. Measure the resistance of the data link between the following terminals on the 12–pin Temperature Control Module (TCM) wiring harness connector: - Pin 4 (CAN+) and Pin 6 (CAN-)	60Ω±10Ω	Result: The measured resistance is 60Ω±10Ω. The terminating resistors are OK. Proceed to Test Step 9. Result: The measured resistance is less than 50Ω. Repair: There are more than 2 terminating resistors installed in the wiring harness or a short circuit has been detected. Repair or replace the damaged components. Proceed to Test Step 10. Result: The measured resistance is 120Ω±10Ω. Repair: There is a problem with a terminating resistor. Check the resistance on each terminating resistor. Replace the failed terminating resistor. Proceed to Test Step 10. Result: The measured resistance is greater than 130Ω. Repair: There is a problem with both terminating resistors or an open circuit has been detected. Determine the cause of the problem. Repair or replace the damaged components. Proceed to Test Step 10.
9. Check the Power and Ground to the TCM A. Turn the keyswitch to ON. B. Measure the voltage between the following TCM wiring harness connector terminals: - Pin 1 (Battery+) and Pin 5 (Battery-)	Battery voltage	Result: The voltage is OK. Repair: Replace the TCM. Proceed to Test Step 10. Result: The voltage is NOT OK. Repair: There is an open or short in the wiring circuit. Repair or replace the wiring circuit. Refer to the machine specific for wiring information. Proceed to Test Step 10.
10. Check for Codes A. Turn the keyswitch to ON. B. Observe the "Active Diagnostic" screen on Cat ET. Wait for 30 seconds for codes that may become active.	Codes	Result: The code did not return. Return the unit 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).