M313D, M315D, M316D, M318D and M322D Excavators and M316D MHPU Mobile Hydraulic Power Unit Electronic System Caterpillar

Illustration 1	g01279353
Medium Pressure Port A Solenoid connections for machines equipped with Medium Pressure Hydraulics.

Illustration 2	g01279020
Medium Pressure Port B Solenoid and Port A Solenoid connections for machines equipped with Medium Pressure Hydraulic System and 2nd High Pressure Hydraulic System.

Note: For machines that are equipped with Medium Pressure Hydraulics only, the wiring connections for the Medium Pressure Port A and Port B Solenoids are different than on the machines that are equipped with the Medium Pressure System AND the 2nd High Pressure Hydraulic System (Auxiliary Hydraulics 2). Refer to the appropriate connection diagram above for your machine configuration. Refer to the full machine Electrical System Schematic for complete harness connections for the circuits.

This diagnostic code is associated with the Medium Pressure Port A Solenoid (attachment). The FMI 05 means that the Machine Control ECM has determined that the circuit current for the solenoid is below normal.

The Medium Pressure Port A Solenoid is a proportional solenoid that is controlled by a Machine Control ECM PWM driver output. In order to control the solenoid, the ECM will change the current of the PWM output signal for the solenoid.

Conditions that could cause this diagnostic code are listed below:

• The solenoid has failed.

• The energize circuit of the solenoid is open or has a poor connection.

• The Medium Pressure/2nd High Pressure Switch has failed. (Med and 2nd High Press equipped machines)

• The return circuit of the solenoid is open.

• The ECM has failed. This is unlikely.

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, 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 following procedure includes some test steps that may apply only to machines that have the medium pressure attachment only OR to machines that have the medium pressure and 2nd high pressure attachment installed. These steps are labeled as: (Med Press only) or (Med and 2nd High Press). Conduct the checks according to the correct connection diagram for your machine configuration that is indicated above.

Test Step 1. CHECK THE SOLENOID

1. (Med and 2nd High Press). Ensure that the 2nd High Pressure/Medium Pressure Switch is in the Medium Pressure position.

2. Disconnect the solenoid from the machine harness.

3. (Med Press only). At the machine harness connector for the solenoid, connect a jumper wire from contact 1 (wire P941-WH) to contact 2 (wire H803-BU).

4. (Med and 2nd High Press). At the machine harness connector for the solenoid, connect a jumper wire from contact 1 (wire P707-PK) to contact 2 (wire H803-BU).

5. Turn the disconnect switch and the key switch to the ON position. Do not start the engine.

6. Observe the status of the CID 2185 FMI 05 diagnostic code.

Expected Result:

The active diagnostic code changes from an FMI "05" to an FMI "06" diagnostic code as the jumper wire is installed.

Results:

• YES - The active diagnostic code changes from an FMI "05" to an FMI "06" diagnostic code when the jumper wire is installed. The solenoid has failed.

  Repair: The solenoid has failed. Repeat this Test Step "CHECK THE SOLENOID" in order to verify the solenoid failure. Replace the solenoid. Verify that the new solenoid corrects the problem.

  STOP

• NO - The CID 2185 FMI 05 diagnostic code remains active. The jumper wire does not affect the status of the diagnostic code. The solenoid is not causing the problem. Proceed to Test Step 2.

Test Step 2. CHECK THE CIRCUIT FOR AN OPEN

1. Turn the key switch and the disconnect switch to the OFF position.

2. The jumper wire that was installed in the previous test step remains in place.

3. Disconnect the machine harness ECM connector J1 from the Machine Control ECM.

4. At the machine harness connector J1 for the ECM, measure the resistance from the supply contact J1-67 (wire P942-YL) to the return contact J1-55 (wire H803-BU).

5. While observing the multimeter resistance measurement, wiggle the machine harness connectors for the ECM. Gently pull on the wires and move the wires around.

6. While observing the multimeter resistance measurement, wiggle the machine harness connector for the solenoid. Gently pull on the wires and move the wires around. Do not disconnect the jumper wire.

7. (Med and 2nd High Press). While observing the resistance measurement, cycle the 2nd High Pressure/Medium Pressure Switch from the Medium Pressure position to the 2nd High Pressure position.

Expected Result:

(Med Press) The resistance measurement is less than 5 ohms at all times during the manipulation of the harness and connectors.

(Med and 2nd High Press) The resistance measurement is less than 5 ohms when the 2nd High Pressure/Medium Pressure Switch is in the Medium Pressure position. The resistance measurement is greater than 5000 ohms when the switch is in the 2nd High Pressure position.

Results:

• OK (Med Press) - The resistance measurement is less than 5 ohms. The circuit is not open in the machine harness. Proceed to Test Step 4.

• OK (Med and 2nd High Press). - The resistance measurement is less than 5 ohms when the 2nd High Pressure/Medium Pressure Switch is in the Medium Pressure position. The resistance measurement is greater than 5000 ohms when the switch is in the 2nd High Pressure position. Proceed to Test Step 4.

• NOT OK (Med Press) - . The resistance measurement is greater than 5 ohms. The resistance measurement is not correct. There is an open or a bad connection in the machine harness.

  Repair: A resistance measurement that is greater than 5000 ohms could indicate that a wire is either not connected or is open. A resistance measurement that is greater 5 ohms but less than 5000 ohms could indicate that one of the connection points in the circuit is not open but is not a good connection.The open or possible bad connection is in supply wire P942-YL or in return wire H803-BU of the machine harness. Refer to the complete machine Electrical System Schematic. Check all of the connectors that are in the solenoid circuit. Ensure that all connections are clean, secure and in good condition. Repair the machine harness or replace the machine harness.

  STOP

• NOT OK (Med and 2nd High Press). - The resistance measurements are not correct according to the "Expected Result " above. There is an open condition in either the switch or the solenoid circuit. Proceed to Test Step 3 in order to isolate the open condition in the circuit.

Test Step 3. CHECK THE HARNESS AND THE SWITCH (MED AND 2ND HIGH PRESS)

This test step is for machines that are equipped with the medium pressure and 2nd high pressure attachment.

The 2nd High Pressure/Medium Pressure Switch is in the Medium Pressure position.

1. At the machine harness connector for the solenoid, verify that a jumper wire is connected from contact 1 (wire P708-YL) to contact 2 (wire H803-BU).

2. At the 2nd High Pressure/Medium Pressure Switch, connect a jumper wire from contact 4 (wire P708-YL) to contact 5 (wire P942-YL).

3. At the disconnected machine harness connector J1 for the ECM, measure the resistance from the supply contact J1-67 (wire P942-YL) to the return contact J1-55 (wire H803-BU).

Expected Result:

The resistance measurement is less than 5 ohms with jumper installed on the switch contacts.

Results:

• YES - The resistance measurement is less than 5 ohms with jumper installed on the switch contacts. The switch has failed.

  Repair: Verify that the 2nd High Pressure/Medium Pressure Switch is in the Medium Pressure position. Repeat this Test Step in order to verify the switch failure. If the 2nd High Pressure/Medium Pressure Switch has failed, replace the switch. Verify that the new switch corrects the problem.

  STOP

• NO - The resistance measurement is more than 5 ohms with the jumper installed on the switch contacts. There is an open or a bad connection in the machine harness.

  Repair: A resistance measurement that is greater than 5000 ohms could indicate that a wire is either not connected or is open. A resistance measurement that is greater 5 ohms but less than 5000 ohms could indicate that one of the connection points in the circuit is not open but is not a good connection.The open or possible bad connection is in the ECM to the switch supply wire P942-YL the switch to solenoid supply wire P708-YL. The return wire H803-BU could also be causing the problem. Investigate these circuits in order to isolate the open or bad connection in the machine harness.Refer to the complete machine Electrical System Schematic. Check all of the connectors that are in the solenoid circuit. Ensure that all connections are clean, secure and in good condition. Repair the machine harness or replace the machine harness.

  STOP

Test Step 4. CHECK THE OPERATION OF THE ECM

Note: This test step will verify that the ECM is monitoring the solenoid circuit correctly. This applies to both the Medium Pressure Solenoid configuration and the Medium Pressure Solenoid/2nd High Pressure configuration.

The disconnect switch and the key start switch remain in the OFF position. The machine harness connector for the solenoid and the Machine Control ECM J1 connector remain disconnected.

1. Remove the jumper wire that was installed in the last test step.

2. At the machine harness connector J1 for the Machine Control ECM, use a 151-6320 Removal Tool to remove the solenoid energize wire P942-YL and socket at contact J1-67 from the harness connector.

3. Reconnect the machine harness J1 connector to the ECM.

4. Turn the disconnect switch and the key start to the ON position.

5. 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 J1-67 through the vacant space in the J1 connector.

6. While observing the status of the active CID 2185 FMI 05 diagnostic code, ground the other end of the 7X-1710 Multimeter Probe to frame ground.

Expected Result:

The CID 2185 FMI 05 diagnostic code is no longer active. A CID 2185 FMI 06 diagnostic code becomes active when the ECM pin at J1-67 is grounded.

Results:

• YES - The CID 2185 FMI 05 diagnostic code is no longer active. A CID 2185 FMI 06 diagnostic code has been activated after the ECM pin is grounded. The ECM has responded correctly to the grounded circuit condition in the solenoid circuit. The ECM is most likely not causing the problem.
  
  Reinstall the disconnected solenoid energize wire back into the correct spot in the ECM connector before proceeding to the next test step.
  
  Proceed to Test Step 5.

• NO - The CID 2185 FMI 05 diagnostic code remains active. The status of the active diagnostic code does not change when the ECM pin for the solenoid is grounded.

  Repair: The ECM has not responded correctly to the grounded condition in the solenoid circuit. The operation of the ECM is not correct.Perform this procedure again. If the same result is found, contact the dealership's Technical Communicator in order to consult with the Caterpillar Dealer Solutions Network.

  STOP

Test Step 5. CHECK THE STATUS OF THE DIAGNOSTIC CODE

1. Inspect the harness connectors and clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.

2. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the sensor circuit.

3. Reconnect all harness connectors. Make sure that the connectors are fully seated and the clips for each connector are completely fastened.

4. Turn the disconnect switch and the key start switch to the ON position.

5. Operate the machine.

6. Check the status of the CID 2185 FMI 05 diagnostic code.

Expected Result:

The CID 2185 FMI 05 diagnostic code is active.

Results:

• YES - The CID 2185 FMI 05 diagnostic code is active. The diagnostic code has not been corrected. The ECM may have failed.

  Repair: Check the circuit again. Use the Caterpillar Electronic Technician (ET) service tool, if available, in order to perform a "Wiggle Test" on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness.If the diagnostic code remains active or if the diagnostic code is repeatedly activated and no cause can be found, flash the ECM with the latest version of software. Ensure that you have the latest version of software for your specific machine and ECM. Refer to the Testing And Adjusting, "Electronic Control Module (ECM) - Flash Program" section of this manual for the correct procedure.If the problem is still present after flashing the latest software to your ECM, contact the dealership's Technical Communicator in order to consult with the Caterpillar Dealer Solutions Network.

  STOP

• NO - The CID 2185 FMI 05 diagnostic code is not active. The diagnostic code does not exist at this time.

  Repair: The initial diagnostic code was probably caused by a poor electrical connection at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.

  STOP