416E, 420E and 430E Backhoe Loaders MID 039 - CID 2735 - FMI 03 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g02115493
"Continuous Flow Switch" circuit diagram

This diagnostic code is associated with the "Loader Auxiliary Continuous Flow" switch. This switch has two inputs to the ECM: a normally open circuit (wire 852-GN) and a normally grounded circuit (wire P993-OR). During normal operation, one switch input is open and the other input is grounded. If each input is shorted to the battery, the ECM will output the FMI 03 diagnostic code. This diagnostic code is detected when both switch inputs are shorted at the same time.

The possible causes of this diagnostic code are listed:

• Short to the + battery terminal.

• The circuit is open.

• A failed switch

• The ECM may have failed. This 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 diagnostic code of CID 2735 FMI 03 is active before performing this procedure.

Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.

Test Step 1. CHECK THE CIRCUIT FOR THE SWITCH.

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

2. Disconnect the J1 and J2 machine harness connectors from the Machine ECM.

3. At the J1 machine harness connector, measure the resistance from contact J1-40 (wire 852-GN) to contact J2-37 (wire P993-OR) with the switch in the Enabled position and the Disable positions.

Expected Result:

The resistance should measure less than 5 ohms for the normally grounded position of the switch. The resistance should measure more than 5000 ohms for the normally open position of the switch.

Results:

• YES - The resistance is correct for each measurement. Proceed to test step 3.

• NO - The resistance measurement is greater than 5000 ohms for one or both measurements. The harness or the switch has failed. Proceed to test step 2.

Test Step 2. CHECK FOR A SHORT.

1. Disconnect the switch from the harness.

2. At the J2 and J1 machine harness connectors, measure the resistance from contact J1-40 and contact J2-37 to all other J1 and J2 contacts.

Expected Result:

The resistance measurement should be greater than 5000 ohms for each measurement.

Results:

• OK - The resistance measurement is greater than 5000 ohms for each measurement. Proceed to Test Step 3.

• NOT OK - The resistance measurement is not greater than 5000 ohms for one or more measurements.

  Repair: The short is in the circuit with the low resistance measurement. Repair the harness or replace the harness. Verify that the problem has been corrected.

  STOP

Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS

1. Inspect the contacts of the harness connectors. Clean the harness connectors.

2. Reconnect all the harness connectors.

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

4. Operate the machine.

5. Check the status of the CID 2735 FMI 03 diagnostic code.

Expected Result:

The CID 2735 FMI 03 diagnostic code is active.

Results:

• YES - The CID 2735 FMI 03 diagnostic code is active. The diagnostic code has not been corrected. The ECM may have failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Troubleshooting, "Electronic Control Module (ECM) - Replace".

  STOP

• NO - The CID 2735 FMI 03 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 or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.

  STOP