416E, 420E and 430E Backhoe Loaders MID 039 - CID 1959 - FMI 03 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g01659774
Schematic of the Position Sensor (Boom Cylinder)

This diagnostic code is associated with the position sensor (Boom Cylinder). The FMI 03 diagnostic code means that the ECM has determined that the voltage of the circuit for the sensor is above normal.

The position sensor is a pulse width modulated sensor that operates at a frequency of approximately 500 hertz.

The possible causes of this diagnostic code are listed below:

• The signal circuit for the sensor is open.

• The signal circuit for the sensor is shorted to the +battery circuit.

• The sensor has failed.

• The power circuit or the ground circuit has failed.

• The ECM has failed. This is unlikely.

Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 1959 FMI 03 is active before performing this procedure.

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

System Response:

A level 1 warning is generated.

The diagnostic code of CID 1959 FMI 03 will be logged in the internal memory of the ECM.

Test Step 1. CHECK FOR POWER AT THE SENSOR.

1. Do not disconnect the harness connector from the sensor.

2. At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along contact 1 (wire 799-WH) for the voltage supply.

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

4. Move the linkage through the full range of motion. Observe that the multimeter remains connected to contact 1 (wire 799-WH). Ensure proper readings while the linkage is in motion. Observe that the other probe of the multimeter remains connected to contact 2 (wire J766-PU).

5. Measure the voltage from contact 1 (wire 799-WH) to contact 2 (wire J766-PU).

Expected Result:

The voltage is 10 Volts DC.

Results:

• OK - The voltage is 10 Volts DC. Proceed to Test Step 3.

• NOT OK - The voltage is not 10 Volts DC. The circuit is not correct. It is likely that the faulty reading is caused by damage to the machine harness.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 2. CHECK THE SIGNAL CIRCUIT OF THE SENSOR.

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

2. At the back of the harness connector for the sensor, remove the 7X-1710 Multimeter Probe from contact 1 and insert the probe along the signal wire (contact 3).

3. At the back of the harness connector for the sensor, insert the 7X-1710 Multimeter Probe along the ground wire (contact 2).

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

5. Monitor the signal of the sensor with the 146-4080 Digital Multimeter .

6. Do not disconnect the sensor or the hardware that is associated with the sensor from the machine. Move the sensor through the full operating range.

7. At the back of the harness connector for the sensor, remove the 7X-1710 Multimeter Probe from contact 3 and test the signal at the sensor.

Expected Result:

The sensor's signal responds in the manner that is described at the beginning of this procedure.

Results:

• OK - The sensor's signal responds correctly. The sensor is operating correctly. Proceed to Test Step 3.

• NOT OK - The sensor's signal does not respond correctly. The sensor is NOT operating correctly.

  Repair: Replace the sensor.

  STOP

Test Step 3. CHECK THE SIGNAL CIRCUIT AT THE ECM.

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

2. Insert the 7X-1710 Multimeter Probes into the back of the ECM connector along J2-15 (wire H901-OR) and J1-70 (wire J766-PU).

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

4. Monitor the signal of the sensor with the 146-4080 Digital Multimeter .

5. Do not disconnect the sensor or the hardware that is associated with the sensor from the machine. Move the sensor through the full operating range.

Expected Result:

The sensor's signal responds in the manner that is described at the beginning of this procedure.

Results:

• OK - The sensor's signal responds correctly. The sensor is operating correctly. Proceed to Test Step 4.

• NOT OK - The sensor's signal does not respond correctly. The harness has failed.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 4. CHECK THE SIGNAL CIRCUIT FOR A SHORT IN THE HARNESS.

1. The key start switch and the disconnect switch remain in the OFF position.

2. Disconnect the machine harness connectors from the sensor and the ECM.

3. Measure the resistance between contact J2-15 (wire H901-OR) and all contacts that are used in the machine harness connectors for the ECM.

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• OK - The resistance is greater than 5000 ohms. The circuit is correct. Proceed to Test Step 5.

• NOT OK - The resistance is less than 5 ohms. The signal circuit is shorted to another circuit in the harness.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 5. CHECK IF THE DIAGNOSTIC CODE REMAINS

1. Inspect the harness connectors and clean the contacts of the machine harness connectors.

2. Reconnect all 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 1959 FMI 03 diagnostic code.

Expected Result:

The CID 1959 FMI 03 diagnostic code is not active.

Results:

• OK - The CID 1959 FMI 03 diagnostic code is not active. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor connection or a short at one of the connectors that was disconnected and reconnected. Resume normal operation.STOP

• NOT OK - The CID 1959 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 failure is not found, replace the ECM. See the Troubleshooting, "Electronic Control Module (ECM) - Replace".

  STOP