D9T Track-Type Tractor Hydraulic System – MID 113 – CID 2596 – FMI 03

Conditions Which Generate This Code:



Illustration 1 g02155456

Brake pressure modulation solenoid connections

The CID 2596 diagnostic code is associated with the brake pressure modulation solenoid. The solenoid is connected to a PWM driver output of the Power Train ECM. The FMI 03 means that the Power Train ECM has detected that the voltage of the circuit is above normal.

Conditions that may cause this diagnostic code to be activated are:

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

  • The ECM has failed. This condition is unlikely.

Note: Poor connections may 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 this diagnostic code is active before performing this procedure.

Note: The resistance of a good Brake Pressure Modulation Solenoid coil is 8.7 ± 0.4 ohms at approximately 25 °C (77 °F). Resistance will increase as the temperatures increase.

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.

Test Step 1. CHECK THE ENERGIZE CIRCUIT OF THE SOLENOID FOR A SHORT CIRCUIT

  1. Turn the key start switch and the disconnect switch to the OFF position.
  1. Disconnect the machine harness connector from the solenoid. Disconnect the machine harness connectors J1 and J2 from the Power Train ECM.
  1. At the Power Train ECM machine harness connector J1, measure the resistance from harness connector contact J1-58 (wire F792-WH) to all of the other contacts that are used in the J1 and J2 connectors for the Power Train ECM.

Expected Result:

Each resistance measurement is greater than 5000 ohms.

Results:

  • YES – Each resistance measurement is greater than 5000 ohms. The resistance measurement does not indicate a short in the machine harness. Proceed to test step 2.

  • NO – Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between wire F792-WH and the circuit that has a low resistance measurement.

    Repair: For information on testing for short circuits and finding short circuits, refer to Testing and Adjusting, “Wiring Harness (Short Circuit) – Test”. Repair the machine harness or replace machine harness.

    STOP

Test Step 2. 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 Power Train ECM remain disconnected.

  1. At the machine harness connector J1 for the Power Train ECM, use a 151-6320 Removal Tool to remove the solenoid energize wire F792-WH and socket at contact J1-58 from the harness connector.
  1. Reconnect the machine harness J1 and J2 connectors to the Power Train ECM.
  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 active CID 2596 FMI 03 diagnostic code.

Expected Result:

The CID 2596 FMI 03 diagnostic code is no longer active. A CID 2596 FMI 05 diagnostic code is now active.

Results:

  • YES – The CID 2596 FMI 03 diagnostic code is no longer active. A CID 2596 FMI 05 diagnostic code has been activated after the solenoid energize circuit was disconnected from the Power Train ECM. The ECM has responded correctly to the open circuit condition in the solenoid circuit.

    Reinstall the disconnected solenoid energize wire back into the correct space in the Power Train ECM connector before proceeding to the next test step.
    Proceed to Test Step 3.

  • NO – The CID 2596 FMI 03 diagnostic code remains active. The status of the active diagnostic code did not change when the solenoid energize wire was disconnected from the ECM. The Power Train ECM has not responded correctly to the open condition in the solenoid circuit. The operation of the ECM is not correct. You may need to replace the Power Train ECM

    Repair: Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the Power Train ECM. Prior to replacing an ECM, contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to Troubleshooting, “Electronic Control Module (ECM) – Replace”.

    STOP

Test Step 3. CHECK THE STATUS OF THE DIAGNOSTIC CODE

  1. Inspect the harness connectors and clean the contacts of the harness connectors that are in the affected circuit. Check the wires for damage to the insulation that can be 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 switch circuit.
  1. Reconnect all harness connectors. Make sure that the connectors are fully seated and the clips for each connector are fastened.
  1. Turn the disconnect switch and the key start switch to the ON position. DO NOT START THE ENGINE.
  1. Determine if the CID 2596 FMI 03 diagnostic code is active.

Expected Result:

The CID 2596 FMI 03 diagnostic code is not active.

Results:

  • OK – The CID 2596 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 2596 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 sensor 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 Troubleshooting, “Electronic Control Module (ECM) – Replace”.

    STOP

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