The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the steering control force circuits of the machine.
| Implement ECM (MID 82) | ||
| DTC | Code Description | System Response |
| 2865-3 | Steering Control force Motor Enable Output: Voltage Above Normal | Steering function will remain intact. Force Feedback will be inactive. |
| 2865-5 | Steering Control force Motor Enable Output: Current Below Normal | Steering function will remain intact. Force Feedback will be inactive. |
| 2865-6 | Steering Control force Motor Enable Output: Current Above Normal | Steering function will remain intact. Force Feedback will be inactive. |
The CID 2865 diagnostic code is associated with the Steering Control Force Feedback Motor Enable Output. The Implement ECM will use this ON / OFF output to enable the operation of the Steering and Transmission Control (Left Steering Joystick).
Possible causes for an FMI 3 Diagnostic code are:
- The ECM has detected that a voltage is present in the enable circuit when no voltage should be present. The feedback motor enable circuit is shorted to another voltage source.
- There is an internal short in the Steering and Transmission Control (Left Steering Joystick) base.
Possible causes for an FMI 5 Diagnostic code are:
- The enable circuit is open or contains a poor connection.
- The ground circuit is open or contains a poor connection.
- There is an internal problem in the joystick base.
- The ECM has failed. A failure of the ECM is unlikely.
Possible causes for an FMI 6 Diagnostic code are:
- The enable circuit is shorted to a ground source.
- There is an internal problem in the joystick base.
- The ECM has failed. A failure of the ECM is unlikely.
Operational Information:
At initial machine start, after the required condition are met, the Implement ECM will turn ON the enable output. When the internal electronics in the joystick base detect the energized enable circuit, joystick operation will begin.
During machine operation, the Implement ECM sends a PWM command signal that ranges between 10 percent and 90 percent to the electronics in the Steering and Transmission Control (Left Steering Joystick) base. The internal electronics in the base of the joystick interpret the duty cycle of the command circuit and supply a corresponding amount of current to the torque feedback motor.
The internal electronics in the base of the joystick also supply a PWM torque feedback signal to the Implement ECM. The acceptable duty cycle range of the feedback circuit is also 10 percent to 90 percent. During normal operation, the PWM duty cycle of the feedback circuit is expected to be close to the duty cycle of the command circuit.
The ECM will use the Force Feedback Motor Torque Sensor duty cycle signal to verify that the correct amount of current is being supplied to the torque motor.
During normal operation when no diagnostic codes for the steering joystick are active and the joystick is stationary, the PWM duty cycles of the torque command signal and the torque sensor circuit will be approximately 50 percent duty cycle, however, the torque sensor feedback duty cycle can differ from the command circuit duty cycle by 25 percent. If the signals differ by more than 25 percent, the ECM will activate a CID 2866 FMI 14 diagnostic code.
The PWM torque command signal from the ECM and the PWM torque sensor feedback signal to the ECM are difficult to measure. When a torque motor diagnostic code or a position sensor diagnostic code is active, the torque motor is disabled and the duty cycles cannot be measured. To measure the signals during normal operation, insert spoon type probes spoon into the appropriate circuit and the ground circuit. When the primary steering is enabled, the duty cycles of both circuits should be in the 10 percent to 90 percent range .
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| Illustration 1 | g03595240 |
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Schematic of the Steering Control Force circuits | |
Note: The diagram above is a simplified schematic of the connections for the steering control circuits. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic, UENR3117 for the 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. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure. For sensors powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.
Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code, listed in the table above, is active before performing this procedure.
| Troubleshooting Test Steps | Values | Results |
|---|---|---|
| 1. Identify The Active DTC Code Associated With Switch Circuit | Code present. |
FMI 3 diagnostic code, proceed to Test Step 2. FMI 5 diagnostic code, proceed to Test Step 4. FMI 6 diagnostic code, proceed to Test Step 6. |
| Begin Process For FMI 3 Troubleshooting HERE | ||
| 2. Check The Energize Circuit For A Short A. Turn key start switch and disconnect switch OFF. B. Access the connectors for the left joystick. Disconnect the harness connector from the joystick P-C3 connector that contains the enable circuit (wire X993-WH(White)). C. Turn the disconnect switch and the key start switch to the ON position. D. At the disconnected P-C3 harness connector, measure for DC voltage between enable circuit contact 1 and the ground circuit contact 2 . Measure for DC voltage between enable circuit contact 4 wire and frame ground. (See schematic, above, for specific pin identification.) |
A measured voltage is greater than 3.0 VDC. |
OK - A voltage measurement is greater than 3.0 VDC. The measurement indicates that the enable circuit is shorted to another voltage circuit in the machine harness. Repair: The amount of voltage that is measured may provide an indication of which circuit is shorted to the enable circuit. The circuit will either be an ECM power supply circuit or a control system power circuit. Determine which circuit is causing the short. Repair the machine harness or replace the machine harness STOP NOT OK - None of the voltage measurements is greater than 3.0 VDC. The measurements are not indicating that the enable circuit is shorted to another voltage source circuit. Proceed to Test Step 3. |
| 3. Check The Operation Of The ECM A. Turn key start switch and disconnect switch to the OFF position. B. At the machine harness connector for the ECM, use a 151-6320 Removal Tool to remove the enable circuit wire and the socket for the wire. (See schematic, above, for specific pin identification.) C. Reconnect the harness connectors to the ECM. D. Turn the disconnect switch and the key start switch to the ON position. E. Use a 7X-1710 Multimeter Probe that is not connected to a multimeter or a similar device to make contact with the ECM pin at J2-3 through the empty space in the J2 connector. F. While observing the status of the active CID 2865 FMI 03 diagnostic code, ground the other end of the 7X-1710 Multimeter Probe to the frame ground. |
The CID 2865 FMI 03 diagnostic code is no longer active. A CID 2865 FMI 04 diagnostic code becomes active when the ECM pin at J2-3 is grounded. |
OK - The CID 2865 FMI 03 diagnostic code is no longer active. A CID 2865 FMI 04 diagnostic code has been activated after the ECM pin is grounded. The ECM has responded correctly to the grounded circuit condition in the circuit. The ECM is most likely not the cause of the problem. Install the enable circuit wire and socket in the original location in the J2 harness connector before proceeding to the next step. Proceed to Test Step 8. NOT OK - The CID 2865 FMI 03 diagnostic code remains active. The status of the active diagnostic code does not change when the ECM pin for the enable circuit is grounded. Repair: The ECM has not responded correctly to the ground condition in the enable circuit. The operation of the ECM is not correct. Ensure that the latest version of software is loaded on the Implement ECM. If the software is not the latest version, flash the latest version of software to the Implement ECM. If the diagnostic code remains active after flashing the latest software version to the ECM, the ECM could be the cause of the problem. Note: Prior to replacing an ECM, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may effect repair time. If the ECM must be replaced, refer to Troubleshooting, "ECM - Replace". STOP |
| Begin Process For FMI 5 Troubleshooting HERE | ||
| 4. Check The Circuits And The ECM A. Turn the key switch and disconnect switch to the OFF position. B. Access the connectors for the left joystick. Disconnect the harness connector from the joystick P-C3 connector that contains the enable circuit (wire X993-WH(White)). C. At the disconnected machine harness connector, connect a jumper wire between enable circuit contact 1 wire (X993-WH(White)) and the ground contact 2 wire (X753-YL(Yellow)). D. Turn the disconnect switch and the key start switch to the ON position. Do not start the engine. E. Observe the status of the CID 2865 FMI 05 diagnostic code. F. Disconnect one end of the jumper wire from the contact 2 ground circuit. Connect this end of the jumper wire to a good frame ground location. G. Observe the status of the CID 2865 FMI 05 diagnostic code. |
The CID 2865 FMI 05 diagnostic code is no longer active. A CID 2865 FMI 06 diagnostic code becomes active when the jumper wire is connected to the ground circuit and to frame ground. |
OK - The CID 2865 FMI 05 diagnostic code is no longer active. A CID 2865 FMI 06 diagnostic code becomes active when the jumper wire is connected. This condition occurs when the jumper wire is connected to the ECM circuit ground and to frame ground. Repair: The ECM has detected the grounded enable circuit for both measurements. The indication is that the ground circuit, the enable circuit, and the ECM are operating correctly. There does not appear to be an open circuit in either the enable circuit or the ECM ground circuit. A problem in the joystick base could be the cause of the problem. Contact the Technical Communicator at your dealership for possible consultation with Caterpillar concerning this problem. Indicate the steps that have been taken and the results that have been observed. If the CID 2865 FMI 05 diagnostic code is no longer active only when the jumper wire is connected to frame ground. There is an open in the ECM ground circuit (X753-YL(Yellow)) between the ECM and the joystick connector. Proceed to Test Step 5 to verify the open circuit. NOT OK- The CID 2865 FMI 05 diagnostic code remains active. The jumper wire does not affect the status of the active diagnostic code when connected to the ECM ground or frame ground. Proceed to Test Step 5. |
| 5. Check The Circuit For An Open A. Turn the disconnect switch and the key start switch to the OFF position. B. At the disconnected harness connector for the joystick, reconnect the jumper wire that was used in the last step between enable circuit contact 1 (wire X993-WH(White)) and the ground contact 2 (wire X753-YL(Yellow)). C. At the Implement ECM, disconnect the machine harness J2. D. At the machine harness connector J2 for the ECM, measure the resistance between contact J2-3 (wire X993-WH(White)) and contact J2-4 (wire X753-YL(Yellow)). E. While the resistance measurements are observed, gently pull on, and wiggle the wires between the module and the ECM locations. |
The measured resistance is less than 5.0 ohms at all times during the manipulation of the harness and connectors. |
OK - The resistance measurement is less than 5.0 ohms. The resistance measurement is not indicating an open or a poor connection in the circuit. Proceed to Test Step 8. NOT OK - The resistance measurement is greater than 5.0 ohms. The resistance measurement is indicating an open circuit or a poor connection in the machine harness. Repair: The open connection or the possible poor connection is in supply wire or in return wire of the machine harness. Repair the machine harness or replace the machine harness. Refer to the complete Electrical System Schematic of the machine, UENR3117. Check all of the connectors that are in the controller signal circuit. Ensure that all connections are clean, that all connections are secure and that all connections are in good condition. A resistance measurement that is greater than 5000 ohms could indicate that a wire is not connected or that a wire is open. A resistance measurement that is greater than 5.0 ohms but less than 5000 ohms could indicate that one of the connection points is poor. STOP |
| Begin Process For FMI 6 Troubleshooting HERE | ||
| 6. Check The Enable Circuit For A Short To Ground A. Turn the disconnect switch and the key start switch to the OFF position. B. Access the connectors for the left joystick. Disconnect the harness connector from the joystick P-C3 connector that contains the enable circuit (wire X993-WH(White)). C. At the Implement ECM, disconnect the J1 and J2 harness connectors. D. At the J2 harness connector, measure the resistance between enable circuit contact J2-3 (wire X993-WH(White)) and frame ground. Measure the resistance between the enable circuit contact J2-3 and each of the other individual contacts that are used in the harness connectors J1 and J2 for the Implement ECM. |
Each measured resistance is greater than 5000 ohms. | OK - Each resistance measurement is greater than 5000 ohms. There does not appear to be a short to a ground source in the machine harness for the Implement ECM. There is a possibility that a ground circuit in another ECM harness could be shorted to the enable circuit. Proceed to Test Step 7. NOT OK - One or more of the resistance measurements is less than 5000 ohms. The resistance measurement is indicating that a short is present in the machine harness. The short is between the wire X993-WH(White) and frame ground. Or the short is between the enable circuit wire and the circuit with the low resistance measurement. Repair: For information on testing for short circuits and finding short circuits, refer to Troubleshooting, "Wiring Harness (Short Circuit) - Test". Repair the machine harness or replace the machine harness. STOP |
| 7. Check For An Internal Short To Ground In The Joystick A. Turn the key start switch and the disconnect switch to the OFF position. B. The joystick P-C3 harness connector remains disconnected from the joystick base. C. At the left joystick connector P-C3, measure the resistance between the enable circuit contact 1 and the joystick base housing. Measure the resistance between the enable circuit contact 1 and each individual ground contact 2 and contact 5. |
Each measured resistance between the enable circuit contact and the grounds is greater than 50 ohms. |
OK - Each resistance measurement is greater than 50 ohms. There does not appear to be an obvious short to ground in the joystick base. Proceed to Test Step 8. NOT OK - One or more of the resistance measurements is less than 50 ohms. The resistance measurement is indicating that a short is present in the base of the joystick. Repair: An internal problem could be present in the joystick. Before replacing the joystick base, contact the Technical Communicator at your dealership for possible consultation with Caterpillar concerning this problem. Indicate the steps that have been taken and the results that have been observed. STOP |
| 8. Check The Status Of The Diagnostic Code A. Turn the disconnect switch and key start switch to the OFF position. B. Reconnect any harness connectors that were disconnected and checked. C. Turn the disconnect switch and the key start switch to the ON position. Allow the steering joystick to attempt an auto enable. D. Start the engine. E. Determine if the CID 2865 FMI 03 diagnostic code is active. |
The CID 2865 FMI 03 diagnostic code is not active. |
OK - The CID 2865 FMI 03 diagnostic code is not active. The diagnostic code does not exist at this time. The initial diagnostic code could have been caused by a poor connection or a momentary condition that reset when the machine was restarted. Resume normal operation. STOP NOT OK - The CID 2865 FMI 03 diagnostic code is still active. The diagnostic code has not been corrected. Repair: Ensure that all possible causes of this diagnostic code have been investigated. If a cause of this problem cannot be found, the joystick base could contain an internal problem. Contact the Technical Communicator at your dealership for possible consultation concerning this problem. Indicate the steps that have been taken and the results that have been observed. The DSN personnel will provide instruction on the next action that is required to resolve this problem. STOP |