950M, 962M, 966M, 972M, 980M, and 982M Wheel Loaders Information Display Caterpillar

Sensor (Data Link Type) - Test

Usage:

972M A78

Graphical Display (MID 53)

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the sensors on the CAN data link of the machine.

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Table 1
Graphical Display (MID 53)
DTC	Code Description	System Response
3318-09	Object Detection Sensor #2: Abnormal Update	Object Detection system is disabled. The system will reactivate when all the parameters on the CAN data link are available.
3318-11	Object Detection Sensor #2: Failure Mode Not Identifiable	Radar mismatch present. Radar warning feature disabled until fault is fixed.
3318-12	Object Detection Sensor #2: Bad Device or Component	The Object Detection is disabled. The status indicator for the system will illuminate red.
3319-09	Object Detection Sensor #3: Abnormal Update	Loss of CAN communications with radar. Radar warning feature disabled until fault is fixed.
3319-11	Object Detection Sensor #3: Failure Mode Not Identifiable	Radar mismatch present. Radar warning feature disabled until fault is fixed.
3319-12	Object Detection Sensor #3: Bad Device or Component	Radar detects internal fault. Radar warning feature disabled until fault is fixed.

Each CAN data link circuit is an input and output of select electronic control modules. The data link is designed to carry communications between the electronic control modules.

Note: For more Object Detection troubleshooting, refer to Systems Operation , UENR1274 , "Cat^® Detect Object Detection System".

Possible causes for an FMI 09 diagnostic code are:

The wrong software is installed on an ECM.
An improper key was used with the MSS system.
The ECM is operating intermittently.
Terminating resistors on the J1939 data link have failed or are missing.
An open or a poor connection in the data link circuit.
Short in the data link circuit.
An ECM or smart device is not powering up or powering down properly.
Lack of key switch input to an ECM or smart device (where applicable).
The energize circuit for the MSS Key Reader may have failed.
Excessive noise on the data link circuit.
One of the ECMs or smart devices has failed. This condition is unlikely.

Possible causes for an FMI 11 diagnostic code are:

Mechanical failure.
Multiple circuit damage.
The wrong radar is being used or the display is configured for the wrong type of radar. (2 vs 1)

Possible causes for an FMI 12 diagnostic code are:

A component has failed.
The Data Link circuit in the machine harness has failed.
An ECM has failed. Failure of an ECM is unlikely.

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Illustration 1	g06223913

Note: The diagram above is a simplified schematic of the Medium Wheel Loader ECM connections. The schematic is electrically correct. However, not all the possible harness connectors are shown. Refer to the latest revision of the machine Electrical Schematic for a complete schematic.

Diagnostic Trouble Code Procedure

Note: Prior to beginning this procedure, inspect the harness connectors that are involved in this circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure, and in good condition. Check the wiring for pinch points or abrasions. Look for and repair areas that indicate wires are exposed. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing a troubleshooting procedure.

Identify the active FMI code associated with the components.
Determine which code is present and use the list below to determine which procedure to follow.

FMI 09 diagnostic code, proceed to Table 2.
FMI 11 diagnostic code, proceed to Table 3.
FMI 12 diagnostic code, proceed to Table 4.

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Table 2
Troubleshooting Test Steps	Values	Results
Begin Process For FMI 09 Troubleshooting HERE
1. Verify The Hardware And The Software Part Numbers⁽¹⁾ A. Verify that the following information is correct: - The part number of the flash software for the ECM is correct. - The part number of the ECM is correct. - The part numbers of the sensors are correct.	All the part numbers are correct.	OK - All the part numbers are correct. Proceed to Test Step 2. NOT OK - All the part numbers are not correct. Repair: The ECM or the sensors have the wrong part number or incorrect flash software is installed. Flash the correct software or replace the incorrect ECM or the sensor with a module that has the correct part number. Refer to the Troubleshooting, "ECM - Flash Program" section for additional information. Proceed to Test Step 11.
2. Check Voltage At The Sensor A. Turn the key start switch and disconnect switch to the OFF position. B. At the machine harness connector for the sensor, insert a 7X-1710 Multimeter Probe along the contact for the sensor power supply. Attach the other probe to frame ground. C. Turn the disconnect switch and key start switch to the ON position. D. Measure the voltage at the sensor between the power supply contact and frame ground.	The voltage measured is battery voltage.	OK - The voltage is between 18 VDC and 32 VDC. The sensor is receiving the correct voltage. Proceed to Test Step 4. NOT OK - The voltage reading is not battery voltage. There is a problem with the machine harness or fuse powering the sensor. Proceed to Test Step 3.
3. Check The Ground Circuit For An Open A. Turn the key start switch and disconnect switch to the OFF position. B. Disconnect the sensor from the machine harness. Disconnect the ECM harness connectors. C. At the machine harness connector for the sensor, measure the resistance between the return contact and frame ground.	The reading is less than 5 Ω when connected to frame ground⁽²⁾.	OK - The resistance measurement is less than 5 Ω⁽²⁾. The ground circuit is correct. Proceed to Test Step 4. NOT OK - The resistance measurement is greater than 5 Ω⁽²⁾. There is a problem with the machine harness. Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit. Repair: Repair or replace the machine harness. Proceed to Test Step 11.
4. Inspect The Harness Connections A. Turn key start switch and disconnect switch OFF. B. Inspect all harness connections related to the CAN data link. Make sure that the connectors are clean and tight. C. Check the connectors for proper mating. Ensure that all the seals are present and in place. D. Check the harness for signs of damage or abrasion. E. Check the wires at the connector. Ensure that the wires are secured tightly into the connector. Take care not to pull the wire out of the connector. F. Check the exposed wires at the connectors for nicks or signs of abrasion. G. Check for moisture inside the connector.	The machine harness connectors are tight and free of corrosion.	OK - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 5. NOT OK - The machine harness connectors are in need of repair. Repair:Repair or replace the machine harness. Proceed to Test Step 11.
5. Check The Voltage Of The Data Link A. Turn the key start switch and the disconnect switch to the ON position. B. Connect Cat^® Electronic Technician (Cat ET) Service Tool and verify which ECMs have logged communication diagnostics. At each ECM or device that is not communicating, use an electrical spoon to measure the voltage. One at a time, measure the voltage of the CAN data link wires to frame ground.	The reading is 0.5 VDC to 4.5 VDC on each wire.	OK - The voltages of the wires for the data links are correct. Proceed to Test Step 8. NOT OK - The voltage is greater than 4.5 VDC. Proceed to Test Step 9. NOT OK - The voltage is less than 0.5 VDC. Proceed to Test Step 6.
6. Check For Short To Ground In the Data Link A. The key start switch and disconnect switch remain OFF. B. Disconnect the machine harness connectors from all electronic control modules that use the suspect CAN data link. C. At the machine harness for the Machine ECM, measure the resistance between frame ground and the positive CAN connector contact of the circuit. D. At the machine harness for the Machine ECM, measure the resistance between frame ground and the negative CAN connector contact of the circuit.	The reading is greater than 5K Ω.	OK - The harness circuit resistance is correct. Proceed to Test Step 7. NOT OK - A reading is less than 5 Ω. The machine harness has failed. Repair: There is a short between frame ground and the contacts of the CAN data link circuit in the machine harness. Repair or replace the machine harness. Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit. Proceed to Test Step 11.
7. Check For A Short Between The Data Link Wires A. The key start switch and the disconnect switch remain in the OFF position. B. Disconnect the terminating resistors if the resistors are a part of the circuit. C. Measure the continuity between the data link wires.	The reading is greater than 5K Ω.	OK - The resistance measurement is correct. Proceed to Test Step 8. NOT OK - The resistance measurement is not correct. The wires for the data link are shorted together. Repair: Repair the machine harness or replace the harness. Proceed to Test Step 11.
8. Check The Terminating Resistors A. The key start switch and the disconnect switch remain in the OFF position. B. The terminating resistors remain disconnected. C. Check the terminating resistor connectors for the following conditions: - Moisture - Corrosion - Damaged Terminals - Loose Connections D. Measure the resistance between terminal A and B of each terminating resistor that was removed from the CAN circuit.	The reading is approx. 120 Ω.	OK - Both resistance measurements are approximately 120 Ω. The terminating resistors have not failed. Reinstall the terminating resistors. Proceed to Test Step 9. NOT OK - One or both resistance measurements are not approximately 120 Ω. At least one of the resistors is not functioning properly. Repair: Replace the terminating resistor or resistors that have failed. Reinstall the terminating resistor that has not failed. Proceed to Test Step 11.
9. Check For A Short To +Battery Circuit In The Data Link A. The key start switch and disconnect switch are OFF. B. All related modules remain disconnected from the machine harness. C. At the machine harness connector for the Machine ECM, measure the resistance between the connector contact for the +Battery and the positive CAN connector contact. D. At the machine harness connector for the Machine ECM, measure the resistance between the connector contact for the +Battery and the negative CAN connector contact.	The reading is greater than 5K Ω.	OK - The reading is greater than 5K Ω. The harness circuit resistance is correct. Proceed to Test Step 10. NOT OK - A reading is less than 5 Ω. The machine harness has failed. Repair: There is a short between the +battery circuit and one of the CAN data link circuits in the machine harness. Repair or replace the machine harness. Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit. Proceed to Test Step 11.
10. Check The Data Link For An Open Note: Two 120 Ω resistors should be on the CAN Data Link. A resistance of 60 Ω should be found at any point on the data link. A. The key start switch and disconnect switch are OFF. B. Use an electrical spoon to connect to the back of the harness connector for each ECM that has communication issues. C. Measure the resistance across the CAN line at each connector to find the open wire.	All resistance measurements are between 55 and 65 Ω.	OK - All resistance measurements are between 55 and 65 Ω. The resistance measurements are correct. Proceed to Test Step 11. NOT OK - At least one resistance measurement is greater than 65 Ω.If the resistance is approximately 115 to 125Ω. There is an open in the harness. If the resistance measurement is 60 Ω, that connector does not have an open between either terminating resistor. If the resistance measurement is 120 Ω, there is an open at that connector between one of the terminating resistors. If the resistance is greater than 5000 Ω, there is an open between that connector and both terminating resistors. If there is a measurement of 40 Ω, there is an extra terminating resistor somewhere on the line. Once the section of harness containing the open is isolated, repair or replace the machine harness. Repair: Repair or replace the machine harness. Proceed to Test Step 11. NOT OK - At least one resistance measurement is less than 55 Ω. Repair: Look for the source of the short by disconnecting the terminating resistors and check the resistance again. If the resistance is still under 55 Ω, continue disconnecting ECMs and devices from the CAN circuit until the resistance goes up. If everything is disconnected from the CAN circuit, and the resistance still is less than 55 Ω the harness has failed. Repair or replace the machine harness. Proceed to Test Step 11.
11. Check If The Diagnostic Code Remains A. Reconnect all harness connectors. Return the machine to normal operating condition. B. Turn the key start switch and the disconnect switch ON. C. Clear all diagnostic codes. D. Operate the machine. E. Stop the machine and engage the safety lock lever. F. Check if the diagnostic code is active.	The diagnostic code is no longer present.	OK - The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. NOT OK - The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. Consultation may affect repair time. STOP.

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⁽¹⁾	Consult your Caterpillar Authorized Dealer for the correct part numbers of the flash software.
⁽²⁾	The resistance reading through an ECM may be higher than 5 Ω.

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Table 3
Troubleshooting Test Steps	Values	Results
Begin Process For FMI 11 Troubleshooting HERE
1. Ensure that detection configuration display matches the number of sensors on the machine. A. Config 1 = 1 Radar B.Config 2 = 2 Radars	The resistance is greater than 10k ohms.	OK - Object detection system radar type configuration code is correct. Proceed to Test Step 2. NOT OK - Configure the object detection system radar type configuration code for the number of sensors on the machine. Repair: Replace the sensor. Proceed to Test Step 6.
2. Check If The Diagnostic Code Remains A. Inspect the harness connectors and clean the contacts of the harness connectors. B. Reconnect all harness connectors. C. Turn key switch and disconnect switch ON. D. Operate the machine. E. Check if diagnostic code is active.	Diagnostic code is no longer present.	OK - Diagnostic code does not exist currently. Initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. NOT OK - Diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing this component, always contact the Technical Communication at your dealership for possible consultation with Caterpillar. The aforementioned consultation may affect repair time. STOP.

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Table 4
Troubleshooting Test Steps	Values	Results
Begin Process For FMI 12 Troubleshooting HERE
1. Check the Switch A. Disconnect the Switch from the machine harness. B. Check if the Diagnostic Code is active.	The Diagnostic Code is not active.	OK - The Diagnostic Code is not active. The Switch has failed. Repair: Replace the Switch. STOP. NOT OK - The Diagnostic Code remains active. Proceed to Test Step 2.
2. Check for an open in the Data Link circuit A. Turn the disconnect switch to the OFF position. B. Disconnect the ECM from the machine harness. C. Place a jumper across the Data Link connections of the machine harness connector for the ECM. D. Measure the resistance between the Data Link connections at the machine harness connector for the Switch.	Reading less than 5 Ω.	OK The resistance is less than 5 Ω. Proceed to Test Step 3. NOT OK - The resistance is greater than 5 Ω. There is an open in the Data Link circuit. Repair: Repair or replace the machine harness. STOP.
3. Inspect The Harness Connections A. The disconnect switch remains in the OFF position. B. Remove the jumper from the previous Test Step. C. Inspect all harness connections that are related to the Data Link circuit. Make sure that the connectors are clean and tight. D. Check the connectors for proper mating. Ensure that all the seals are present and in place. E. Check the harness for signs of damage or abrasion. F. Check the wires at the connector. Ensure that the wires are secured tightly into the connector. Take care not to pull the wire out of the connector. G. Check the exposed wires at the connectors for nicks or signs of abrasion. H. Check for moisture inside the connector. I. Check the connectors for dirty contacts or corroded contacts. J. Check each pin and each socket of the machine harness connectors. Ensure that the contacts are properly installed. The contacts should mate correctly when the two pieces of the connector are placed together.	The machine harness connectors are tight and free of corrosion.	OK - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 4. NOT OK - The machine harness connectors are in need of repair. Repair:Repair or replace the machine harness. STOP.
4. Check If The Diagnostic Code Remains A. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit. B. Reconnect all harness connectors. Verity that the connectors are fully seated and clips are fastened. C. Turn the disconnect switch and the key start switch to the ON position. D. Operate the machine. E. Check the status of the suspect diagnostic code.	The diagnostic code is not active.	OK - The suspect diagnostic code is not active. The diagnostic code does not exist now. Repair: The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors. Resume normal machine operation. STOP. NOT OK - The suspect diagnostic code is active. The diagnostic code has not been corrected. The Machine ECM may have failed. A failure of the Machine ECM is unlikely. Repair: If the cause of the diagnostic code is not found, the ECM may have failed. A failure of the Machine ECM is unlikely. Prior to replacing an ECM, always contact the Technical Communicator for your dealership for possible consultation with Caterpillar^®. This consultation may greatly reduce repair time. STOP.