C175-16 Locomotive Engine Caterpillar

Data Link - Test

Usage:

Use this procedure to troubleshoot a problem with the data link system. Also, use this procedure if one of the following diagnostic codes is active or easily repeated.

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Table 1
J1939 Code and Description	CDL Code and Description	Comments
639-9 J1939 Network #1 : Abnormal Update Rate	247-9 SAE J1939 Data Link : Abnormal Update Rate	Communication has been lost to one or more of the devices on the datalink. If multiple devices are not communicating, there is likely a problem with the data link wiring, power, or ground circuits.
639-14 J1939 Network #1 : Special Instruction	247-14 SAE J1939 Data Link : Special Instruction	The affected Electronic Control Module (ECM) is missing expected parameters.
1231-9 J1939 Network #2 : Abnormal Update Rate	2348-9 SAE J1939 Data Link #2 : Abnormal Update Rate	Communication has been lost to one or more of the devices on the datalink. If multiple devices are not communicating, there is likely a problem with the data link wiring, power, or ground circuits. Note: This code will log on the aftertreatment ECM if the Emergency Fuel Cutoff (EFCO) switch is used to shutdown the engine.
1231-14 J1939 Network #2 : Special Instruction	2348-14 SAE J1939 Data Link #2 : Special Instruction	The affected ECM is missing expected parameters.
2853-9 Communications Connection : Abnormal Update Rate	N/A	Communication has been lost to one or more of the devices on the datalink. If multiple devices are not communicating, there is likely a problem with the data link wiring, power, or ground circuits.
4193-9 Engine Coolant Pump Outlet Temperature : Abnormal Update Rate	2854-7 Coolant Temperature Control Module : Not Responding Properly	N/A
4193-14 Engine Coolant Pump Outlet Temperature : Special Instruction	2349-14 Engine Coolant Pump Outlet Temperature Sensor : Special Instruction	N/A

If the Cat^® Electronic Technician (ET) will not communicate with the ECM, refer to Troubleshooting, "Electronic Service Tool Does Not Communicate" before you begin this procedure. The procedure verifies that electrical power is being supplied to the ECM and to the service tool connector.

The Systems Communication Status is located under the diagnostics tab in Cat ET. Click the "System Communication Status" option. Once the screen opens up, the information will automatically be loaded from the ECM. If there is an issue with the data link and the data link is repaired, the "Load from ECM" button will have to be clicked again to see the updated status. If there are communication issues between multiple modules, each module can be selected individually to determine which components are having communication issues. If the problem is intermittent, the "View History" button can be clicked to see all the communication faults that have previously logged.

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Table 2
Cat^® ET Diagnostic Code Cross Reference to Wiring Schematic
Code Description	Data Link
J1939 Network #1	Can A (Global)
J1939 Network #2	Can B (Local)

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Illustration 1	g06085122

-9 Detected Problems:

Device 1 is unable to communicate on the data link.

Device 1 cannot communicate with other Devices on the data link, but can communicate with the service tool, indicating a problem with the data link wiring.

Device 1 is unable to communicate with Device 2 on the data link.

Device 1 cannot communicate with Device 2, indicating a problem with the data link wiring, power or ground circuit, or Device 2.

-14 Detected Problems:

Device 1 is unable to obtain a network address on the data link.

Device 1 is trying to claim the same address as another Device. An example of this is two Devices being configured the same.

Device 1 detects a failed address claim from Device 2 on the data link.

Device 1 detects that Device 2 is trying to claim the same address as another Device.

Device 1 is not receiving all expected parameters from Device 2 on the data link.

A component is configured as installed in the ECM, but is not installed on the application.
The incorrect component is installed.
The incorrect software file has been installed.

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Table 3
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 diagnostic code.	Codes	Result: A 4193-9 code is present. Proceed to Test Step 11. Result: A 4193-14 is present code. Proceed to Test Step 3. Result: A 639-9, 1235-9 639-9, 639-14 are present. Proceed to Test Step 2.
2. Use the "System Communication Status" to Determine the Communication Issue A. In Cat ET, click the "Diagnostics" tab on the tool bar. B. Select the "System Communication Status" option from the drop-down list.	Component Identified	Result: A 625-9 code is present. Check the configuration of the secondary ECM to make sure that it is configured for the correct location. The secondary ECM is Device 2. Proceed to Test Step 7. Result: A -9 code is active. Refer to the above -9 detected problems for additional information. Proceed to Test Step 6. Result: A -14 code is active. Refer to the above -14 detected problems for additional information. If the NOx sensors are listed as ECM 2, proceed to Test Step 3. For all other components, proceed to Test Step 4.
3. Check the Part Number of the Component A. Locate the part number for 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 number is incorrect for the application. Repair: Replace the component with the correct part number. Refer to Special Instruction, REHS8151 for special handling instructions if replacing a NOx sensor. Proceed to Test Step 10. Result: The part number is correct for the application. Proceed to Test Step 4.
4. Check for Incorrect Configuration Parameters A. Connect Cat ET. B. Use Cat ET to verify that the correct parameters are being used.	Parameters	Result: The parameters are correct. Proceed to Test Step 5. Result: The parameters are not correct. Repair: Input the correct parameters. Refer to Troubleshooting, "Configuration Parameters" for additional information. If the problem is not resolved, proceed to Test Step 5.
5. Ensure that the latest Flash File Software is Installed in the ECM A. Connect Cat ET. B. Use Cat ET to verify that the correct flash file is being used.	Flash File	Result: The latest flash file is installed and the code present was 4193-14. Proceed to Test Step 13. Result: The latest flash file is installed and the code present was not 4193-14. Proceed to Test Step 10. Result: The latest flash file is not installed. Repair: Perform the following procedure: 1. Download the latest flash file from SIS web. 2. Install the software into the ECM. Refer to Troubleshooting, "ECM Software - Install" for additional information. Proceed to Test Step 10.

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Illustration 2	g03846524
Device 1 present (1) Column 1

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Illustration 3	g03846007
Device 1 and Device 2 present (1) Column 1 (2) Multiple Device 1 and Device 2 can be displayed (3) Device 2 is the affected ECM/device that cannot be recognized by Device 1. Device 2 is the ECM/device with the problem.

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Table 4
Troubleshooting Test Steps	Values	Results
6. Use the System Communication Status to Determine the Cause A. Determine if both ECM 1 and ECM 2 are present in the "ECM" column (1) within the "System Communication Status" screen. Refer to Illustration 3.	Component Identified	Result: ECM 1 and ECM 2 are both present. Record the devices identified as ECM 1 and ECM 2 in column 1. Refer to Illustration 3. Proceed to Test Step 7. Result: Only ECM 1 is present. Record the device identified as ECM 1 in column 1. Refer to Illustration 2. Proceed to Test Step 9.
7. Check the Resistance of the Data link A. Turn the breaker to the OFF position. B. Measure the resistance of the data link between the following ECM 2 wiring harness connector terminals: - +Data link and -Data link	60+/-10 Ohms	Result: The resistance is less than 50 Ohms. Repair: There are more than 2 terminating resistors installed in the wiring harness or a short circuit has been detected. Repair or replace damaged components. Proceed to Test Step 10. Result: The resistance is 120 ±10 Ohms. 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 resistance is greater than 130 Ohms. 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 damaged components. Proceed to Test Step 10. Result: The resistance is 60 ±10 Ohms. The terminating resistors are OK. Proceed to Test Step 8.
8. Check the Power and Ground to ECM 2 A. Turn the breaker to the ON position. B. Measure the voltage between the following ECM 2 wiring harness connector terminals: - +Battery and -Battery	Battery Voltage	Result: The voltage is not equal to battery voltage. Repair: There is an open or short in the wiring circuit. Repair or replace the wiring circuit. Refer to the machine-specific schematic for wiring information. Proceed to Test Step 10. Result: The voltage is equal to battery voltage. Repair: Replace the component identified as ECM 2. Refer to Special Instruction, REHS8151 for special handling instructions if replacing a NOx sensor. Proceed to Test Step 10.
9. Check the Resistance of the Data Link A. Turn the breaker to the OFF position. B. Measure the resistance of the data link between the following ECM 1 wiring harness connector terminals: - +Data link and -Data link	60+/-10 Ohms	Result: The resistance is less than 50 Ohms. Repair: There are more than two terminating resistors installed in the wiring harness or a short circuit has been detected. Repair or replace damaged components. Proceed to Test Step 10. Result: The resistance is 60 ±10 Ohms. The terminating resistors are OK. Repair: Check the power, ground, and keyswitch (if applicable) supply to each module on the affected data link. Refer to the appropriate wiring diagram. Repair the power or ground supply to the modules. Note: The breaker must be in the ON position when checking the power supply. Proceed to Test Step 10. Result: The resistance is 120 ±10 Ohms. 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 resistance is greater than 130 Ohms. Repair: There is a problem with the wiring harness between ECM 1 and the splice point into the data link wiring. Refer to the appropriate wiring diagram. Determine the cause of the problem. Repair or replace damaged components. Proceed to Test Step 10.
10. Use the "Systems Communication Status" to Determine the Communication Issue A. In Cat ET, click the "Diagnostics" tab on the tool bar. B. Select the "System Communication Status" option from the drop-down list. C. Click the "Load from ECM" button to determine if any devices are not communicating.	Component Identified	Result: The "Systems Communication Status" does not show any communication issues. Return to service.
11. Check the Resistance of the Datalink at the Coolant Temperature Control Module Connector A. Turn the breaker to the OFF position. B. Disconnect the coolant temperature control module from the engine harness connector. C. Measure the resistance of the data link between the following pins: - 4 and 6 of the engine harness connector.	60±10 Ohms	Result: The resistance is less than 50 Ohms. Repair: There are more than two terminating resistors installed in the wiring harness or a short circuit has been detected. Repair or replace damaged components. Proceed to Test Step 13 Result: The resistance is 120 ± 10 Ohms. Repair: There is a problem with the terminating resistor. Check the resistance on each terminating resistor. Replace the failed termination resistor. Proceed to Test Step 13 Result: The resistance is 130 Ohms. Repair: There is a problem with the terminating resistor or an open circuit has been detected. Determine the cause of the problem. Repair or replace damaged components. Proceed to Test Step 13 Result: The resistance is 60 ± 10 Ohms. The termination resistors are OK. Proceed to Test Step 12
12. Check the Power and Ground at Coolant Temperature Control Module Connector A. Turn the breaker to the ON position. B. Disconnect the coolant temperature control module from the engine harness connector. C. Measure the resistance of the data link between the following pins: - 1 and 5 of the engine harness connector.	Voltage	Result: The voltage is not equal to battery voltage. Repair: There is an open or short in the wiring circuit. Repair or replace the wiring circuit. Refer to the machine schematic for wiring information. Proceed to Test Step 13 Result: The voltage is equal to battery voltage. Repair: replace the component identified as ECM 2. Refer to Special Instruction, REHS8151 for special handling instruction if replacing a NOx sensor. Proceed to Test Step 13
13. Check for Codes A. Connect Cat^® Electronic Technician (ET) to the service tool connector. B. Determine if a code is active or logged.	Codes	Result: There are no codes present. Return engine to service. Result: There are no codes present.

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).