416E, 420E and 430E Backhoe Loaders MID 039 - CID 2530 - FMI 03 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g02114634
Schematic of the "Left-Hand Joystick Thumbwheel"

This diagnostic code is associated with the "Left-Hand Joystick Thumbwheel" position sensor. The FMI 03 diagnostic code means that the ECM has determined that the PWM signal for the sensor is above normal.

The sensor operates at a frequency of approximately 500 hertz. The sensor has an operating duty cycle of 20% to 80%.

Some possible causes of the diagnostic code are listed below:

• The sensor has failed.

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

• The energize circuit of the sensor is shorted to the +battery circuit.

• The ECM has 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 2530 FMI 03 is active before performing this procedure.

Test Step 1. CHECK THE "THUMBWHEEL SENSOR"

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

2. Access the three "contact joystick connector" for the "Left-Hand Joystick Thumbwheel" and disconnect the sensor from the machine harness.

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

4. Check the status of the CID 2530 FMI 04 diagnostic code.

Expected Result:

The CID 2530 FMI 03 diagnostic code is no longer active. A CID 2530 FMI 04 diagnostic code is now active.

Results:

• YES - The active diagnostic code has changed to a CID 2530 FMI 04 diagnostic code.

  Repair: The "thumbwheel position sensor" on the Left hand joystick has failed. Replace the Left hand joystick.

  STOP

• NO - The active diagnostic code has not changed. The CID 2530 FMI 03 diagnostic code is still active. Proceed to Test Step 2.

Test Step 2. CHECK THE SIGNAL CIRCUIT OF THE SENSOR FOR A SHORT TO THE +BATTERY CIRCUIT

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

2. The "thumbwheel position sensor" remains disconnected from the machine harness. Disconnect the machine harness connectors J-1 and J-2 from the ECM.

3. At the machine harness connector for the ECM J1, measure the resistance from signal contact J2-25 (wire M952-BU) to all J-1 and J2 contacts that are connected to the +battery.

Expected Result:

Each resistance measurement is greater than 5000 ohms.

Results:

• OK - Each resistance measurement is greater than 5000 ohms. The signal circuit in the machine harness is correct. Proceed to Test Step 3.

• NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between J2-25 (wire M952-BU) and the circuit that has a low resistance measurement.

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

  STOP

Test Step 3. CHECK THE "ENERGIZE VOLTAGE"AT THE SENSOR

1. Reconnect machine harness connectors J-1 and J-2 to the ECM.

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

3. At the disconnected machine harness connector for the "thumbwheel position sensor", measure the DC voltage between the following:
   • Energize contact 1 (wire X800-OR) and ground contact 2 (wire J764-BR).

Expected Result:

The voltage measurement should be approximately 8 DCV.

Results:

• OK - The voltage measurement is approximately 8 DCV. The energize circuit is correct. Proceed to Test Step 5.

• NOT OK - The voltage measurement is ABOVE 8 DCV. The energize circuit could be shorted to a + battery circuit. Proceed to Test Step 4.

Test Step 4. CHECK THE ENERGIZE CIRCUIT OF THE SENSOR FOR A SHORT TO THE +BATTERY CIRCUIT

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

2. The "thumbwheel position sensor" remains disconnected from the machine harness. Disconnect the machine harness connectors J-1 and J-2 from the ECM.

3. At the machine harness connector of the ECM J1, measure the resistance from the supply of the sensor J2-25 (wire M952-BU) to all J-1 and J2 contacts that are connected to the +battery.

Expected Result:

Each resistance measurement is greater than 5000 ohms.

Results:

• OK - Each resistance measurement is greater than 5000 ohms. The energize circuit in the machine harness is correct. Proceed to Test Step 5.

• NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between J2-25 (wire M952-BU) and the circuit that has a low resistance measurement.

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

  STOP

Test Step 5. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE

1. Inspect the contacts and clean the contacts of the 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. Determine if the CID 2530 FMI 03 is active.

Expected Result:

The CID 2530 FMI 03 is still active.

Results:

• YES - The CID 2530 FMI 03 is still active.

  Repair: Repeat this entire test procedure again. If the diagnostic code is still active, the ECM may be faulty. It is unlikely that the ECM has failed. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace ".

  STOP

• NO - The CID 2530 FMI 03 is not active. The problem 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