The following is a list of Diagnostic Trouble Codes (DTC) that are associated with the Cat data link of the machine. The Cat data link allows communication between various ECM modules on model 621K OEM Wheel Tractor.
| Implement ECM (MID 82) | ||
|---|---|---|
| DTC | Code Description | System Response |
| 248-9 | Cat Data Link - Abnormal Update Rate | Communication across the data link will be interrupted. Some machine functions may be disabled. |
| 590-9 | Engine Control Module - Abnormal Update Rate | Communication between the Implement ECM and the Engine ECM modules will be interrupted. |
| 967-9 | Machine Application - Abnormal Update Rate | Communication with the Machine Application ECM will be interrupted. Some machine functions may be disabled. |
| 1273-9 | Chassis Control Module - Abnormal Update Rate | Communication with the Transmision/Chassis ECM will be interrupted. Some machine functions may be disabled. |
The following is a list of Diagnostic Trouble Codes (DTC) that are associated with the Cat data link of the machine. The Cat data link allows communication between various ECM modules on model 621K OEM Wheel Tractor.
| Transmission/Chassis ECM (MID 27) | ||
|---|---|---|
| DTC | Code Description | System Response |
| 248-9 | Cat Data Link - Abnormal Update Rate | Communication across the data link will be interrupted. Some machine functions will be disabled. |
| 296-9 | Transmission Control - Abnormal Update Rate | Communication between the Transmission ECM and other ECM modules will be interrupted. |
| 590-9 | Engine Control Module - Abnormal Update Rate | Communication between the Transmission ECM and the Engine ECM modules will be interrupted. |
| 596-9 | Implement Control - Abnormal Update Rate | Communication between the Transmission ECM and the Implement ECM modules will be interrupted. |
Each Cat 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. The data link is not a visible component. The data link consists of internal control circuits and the connecting harness wiring.
Possible Causes and Schematics
The diagnostic code is caused by abnormal communications between specific ECM modules via the Cat Data Link. The update rate is not correct. If a diagnostic code is present, correct the related diagnostic code.
The DTC 248-9 is used as a companion code and indicates a J1939 data-link problem. This DTC indicates that a specific ECM has lost all communication with another ECM.
Note: The 248-9 DTC will never be activated as a stand-alone diagnostic code.
Possible causes for an FMI 9 failure mode code are:
- A fuse for one of the ECM modules may have failed.
- The software is incorrect or incompatible for one of the modules within the data link.
- The machine harness has failed.
- One of the ECM modules in the data link has failed.
The DTC is recorded when Cat® Electronic Technician (Cat ET) does not receive the expected information from the ECM associated with the DTC. The information is communicated over the Cat data link.
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| Illustration 1 | g03348367 |
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AVS Data Link circuit connections for 621K OEM Wheel Tractor | |
Note: The diagram above is simplified schematic of the Cat data link connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic for your specific machine. Refer to the list below to identify the correct schematic for your machine.
- Electrical Schematic, UENR2689 for the 621K Tractor/Scraper.
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.
| Troubleshooting Test Steps | Values | Results |
|---|---|---|
| 1. Identify The Active DTC Code Associated With The Cat Data Link | Code present |
FMI 9, proceed to Test Step 2. |
| Begin Process for FMI 9 Troubleshooting HERE | ||
| 2. Verify The Hardware And The Software Part Numbers(1) A. The part number of the flash software for the suspected ECM. B. The part number of all components related to the faulty Data Link Circuit. |
All part numbers are correct. |
OK - All part numbers are correct. Proceed to Test Step 3. NOT OK - All of the part numbers are not correct. Repair: A module has the wrong part number or the incorrect flash software is installed. Replace the incorrect module with a module that has the correct part number. Flash the correct software. See the Troubleshooting, "ECM Software - Install" section of this manual for additional information. STOP |
| 3. Check For Shorts 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 Cat Data Link. C. At the machine harness for the ECM, measure the resistance between the positive data link contact and all other J1 and J2 contacts. C. At the machine harness for the ECM, measure the resistance between the negative data link contact and all other J1 and J2 contacts. |
The reading is greater than 5K Ω. |
OK - The harness circuit resistance is correct. Proceed to Test Step 4. NOT OK - A reading is less than 5 ohms. The machine harness has failed. Repair: Short between frame ground and the contacts of the Cat Data Link circuit in the machine harness. Repair or replace the machine harness. Note: A resistance that is greater than 5 ohms but less than 5K ohms would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K ohms would indicate an open in the circuit. STOP |
| 4. Check For Open Harness A. The key start switch and disconnect switch are OFF. B. All related electronic control modules remain disconnected from the machine harness. D. At the machine harness connector for the suspected ECM, place a jumper wire between the positive and negative contacts for the Cat data link. E. At the machine harness connector for a known good ECM, measure resistance between the positive and negative contacts for the Cat data link. |
Reading is less than 5 Ω. |
OK - The Cat data link circuit in the machine harness is correct. Proceed to Step 5. NOT OK - A reading is greater than 5K ohms. The machine harness has failed. Repair: The Cat data link circuit is open in the machine harness. Repair or replace the machine harness. Note: A resistance that is greater than 5 ohms but less than 5K ohms would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K ohms would indicate an open in the circuit. STOP |
| 5. Check If The Diagnostic Code Remains. A. Turn the key start switch and the disconnect switch ON. B. Clear all diagnostic codes. C. Operate the machine. D. Stop machine and engage the safety lock lever. E. Check if the diagnostic code for the sensor is active. |
The code for the sensor is NO longer present. |
OK - The diagnostic code does not exist at this time. The initial diagnostic code may have been caused by a poor electrical connection or a short at one of the harness connections. Resume machine operation. STOP NOT OK - The diagnostic trouble code has not been corrected. Repair: Recheck the circuit and perform this procedure again. If the diagnostic code is still active, the ECM indicated by the DTC may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may greatly reduce repair time. Follow the procedure in Testing and Adjusting, "ECM - Replace" to replace the ECM. STOP |
| (1) | Consult your AVSpare Authorized Dealer for the correct part numbers of the flash software. |