D9T Track-Type Tractor Hydraulic System – MID 113 – CID 0722 – FMI 03

Conditions Which Generate This Code:



Illustration 1 g03326688

Connections of the secondary brake solenoid

The CID 0722 diagnostic code is associated with the secondary brake solenoid. The circuit is connected to an ON/OFF output of the Power Train ECM. The FMI 03 means the Power Train ECM has determined that voltage is present in the circuit and no voltage should be present.

The service brake switch is depressed when the service brake pedal is fully depressed. When the switch is depressed, system voltage is directed to the secondary brake solenoid through fuse 9 and the switch contacts. Then, the secondary brake is engaged. The resistance of the solenoid coil is approximately 42 ohms at 25° C (77° F). The resistance will increase as the temperatures increase.

The possible causes of this diagnostic code are listed:

  • The switch has failed.

  • The energize circuit of the solenoid is shorted to another voltage source.

  • The ECM has failed. An ECM failure is unlikely.

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 0722 FMI 03 diagnostic code is active before performing this procedure.

Note: Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, that all connections are secure and that all connections are in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.

Note: Use a digital multimeter for the measurements in this procedure.

Test Step 1. CHECK THE SWITCH

  1. Turn the key start switch and the disconnect switch to the OFF position.
  1. At the fuse panel, remove fuse 9 from the fuse holder.
  1. Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.
  1. Observe the status of the CID 0722 FMI 03 diagnostic code.

Expected Result:

The CID 0722 FMI 03 diagnostic code is no longer active when the fuse is removed.

Results:

  • OK – The CID 0722 FMI 03 diagnostic code is no longer active when the fuse is removed. The switch has failed.

    Repair: Install the fuse in the fuse holder. Check the continuity of the switch in each position. Replace the switch. Verify that the new switch has corrected the problem.

    STOP

  • NOT OK – The CID 0722 FMI 03 diagnostic code remains active when the fuse is removed. The switch is not causing the problem.

    Repair: Install the fuse in the fuse holder before proceeding to the next Test Step.

    Proceed to Test Step 2.

Test Step 2. CHECK THE ENERGIZE CIRCUIT OF THE SOLENOID FOR A SHORT

  1. Turn the key start switch and the disconnect switch to the OFF position.
  1. Disconnect the solenoid from the harness connector.
  1. Disconnect the J1 and J2 machine harness connectors from the ECM.
  1. While the service brake pedal is released, measure the resistance from contact J2-5 wire (G731-GY) to all of the other contacts in the connectors.

Expected Result:

Each resistance measurement is greater than 5000 ohms.

Results:

  • YES – Each resistance measurement is greater than 5000 ohms. The circuit is correct. Proceed to Test Step 3.

  • NO – One or more of the resistance measurements is less than 5000 ohms. There is a short in the circuit.

    Repair: The short is between wire (G731-GY) and the circuit with the low resistance measurement. Refer to the Electrical System Schematic for your machine. Examine all of the connectors for possible locations of a short. For information on testing for shorts and finding short circuits, refer to Troubleshooting, “Wiring Harness (Short Circuit) – Test”. Repair the machine harness or replace the machine harness.

    STOP

Test Step 3. CHECK THE OPERATION OF THE ECM

The disconnect switch and the key start switch remain in the OFF position. The machine harness connectors for the solenoid and the ECM remain disconnected.

  1. At the J2 machine harness connector for the ECM, use a wire removal tool in order to remove wire (G731-GY) and the socket at contact J2-5 from the harness connector.
  1. Reconnect the J1 and J2 machine harness connectors to the ECM.
  1. Turn the disconnect switch and the key start switch to the ON position.
  1. Observe the status of the CID 0722 FMI 03 diagnostic code.

Expected Result:

The CID 0722 FMI 03 diagnostic code is no longer active. An FMI 05 diagnostic code is now active.

Results:

  • YES – The CID 0722 FMI 03 diagnostic code is no longer active. An FMI 05 diagnostic code is activated after the energize circuit is disconnected. The ECM has responded correctly to the open circuit condition in the solenoid circuit. Reinstall the disconnected wire to the correct location in the ECM connector before proceeding to the next test step. Proceed to Test Step 4.

  • NO – The CID 0722 FMI 03 diagnostic code remains active. The status of the active diagnostic code did not change when the wire was disconnected from the ECM.

    Repair: The ECM has not responded correctly to the open circuit condition in the solenoid circuit. The operation of the ECM is not correct.An ECM failure is unlikely. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, the ECM may have failed. Prior to replacing an ECM, always contact your technical communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. Refer to Troubleshooting, “Electronic Control Module (ECM) – Replace”.

    STOP

Test Step 4. CHECK THE STATUS OF THE DIAGNOSTIC CODE

  1. Inspect the harness connectors. Clean the contacts of the harness connectors and check the wires for damage to the insulation. Damage is caused by excessive heat, battery acid, or chafing.
  1. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.
  1. Reconnect all of the harness connectors in order to make sure that the connectors are fully seated. Also, make sure that the clips for each connector are fastened.
  1. Turn the disconnect switch and the key start switch to the ON position.
  1. Determine if the CID 0722 FMI 03 diagnostic code is active.

Expected Result:

The CID 0722 FMI 03 diagnostic code is not active.

Results:

  • OK – The CID 0722 FMI 03 diagnostic code is not active. The diagnostic code does not exist at this time. The initial diagnostic code may have been caused by a poor electrical connection that was corrected when a harness connector was disconnected and reconnected.

    Repair: Resume normal operation.

    STOP

  • NOT OK – The CID 0722 FMI 03 diagnostic code is active. The problem has not been corrected.

    Repair: With Caterpillar Electronic Technician (Cat ET), if available, perform a “Wiggle Test” on the secondary brake solenoid circuit in the machine wiring harness. The wiggle test may detect momentary or intermittent shorts or opens in the machine wiring harness.If all possible causes of the problem have been investigated and no problem can be found, you may need to replace the Power Train ECM.Prior to replacing an ECM, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time and expense. If the ECM must be replaced, refer to Testing and Adjusting, “Electronic Control Module (ECM) – Replace”.

    STOP

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