AP-1000D, AP-1055D, AP-655C, BG-2255C, BG-2455D and BG-260D Asphalt Pavers MID 039 - CID 0154 - FMI 08 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g00952428

This diagnostic code is associated with the left drive speed sensor. The FMI 08 means that the ECM has determined that the signal frequency or the signal pulse width is not within the expected range.

There will be two sensor signals for each motor. One of the signals is primary and one signal is secondary. A diagnostic code is generated if the primary signal and the secondary signal are not in synchronization. A diagnostic code is generated if the signals between both sensors are not in synchronization.

The possible causes of this diagnostic code are listed below:

• The sensor has failed.

• Intermittent connections or poor connections

• Mechanical devices are loose.

• 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 0153 FMI 08 is active before performing this procedure.

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

System Response:

When this diagnostic code is active, the following occurs:

• The fault lamp for the propulsion system is activated.

• The action lamp is activated.

• The maximum speed is limited.

Test Step 1. CHECK THE RETURN CIRCUIT

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

2. Disconnect the machine harness connector from the sensor.

3. At the machine harness connector for the sensor, measure the resistance between return circuit J1-12 (A275-BK) and the frame ground.

Expected Result:

The resistance should measure 5 ohms or less.

Results:

• OK - The return circuit is correct. Proceed to test step 2.

• NOT OK - The return circuit (A275-BK) in the machine harness is open.

  Repair: Repair the harness or replace the harness.

  Stop.

Test Step 2. CHECK THE SENSOR SUPPLY CIRCUIT AT THE SENSOR

1. The machine harness remains disconnected from the sensor.

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

3. At the machine harness for the sensor, measure the voltage. Measure the voltage from contact 1 (wire K983-BU) and contact 3 (wire A275-BK).

Expected Result:

The voltage that is measured is between 8 ± 0.5 DCV.

Results:

• OK - The sensor supply circuit is correct. Proceed to test step 3.

• NOT OK - The sensor supply circuit is open between the sensor and the ECM.

  Repair: Repair the harness or replace the harness.

  Stop.

Test Step 3. CHECK THE ECM AND THE HARNESS.

1. The key start switch remains ON.

2. The machine harness remains disconnected from the sensor.

3. At the machine harness for the sensor, measure the voltage for the signal circuit 1. Measure the voltage from contact 2 (G808-BU) and contact 3 (A275-BK).

4. At the machine harness for the sensor, measure the voltage for the signal circuit 2. Measure the voltage from contact 4 (G809-GN) and contact 3 (A275-BK).

Expected Result:

The voltage that is measured is 5 ± 0.5 DCV for both measurements.

Results:

• OK - The signal circuits are correct. Proceed to test step 6.

• NOT OK - The machine harness or the ECM has failed. Proceed to test step 4.

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

1. The machine harness remains disconnected from the sensor.

2. Turn the key start switch to the OFF position.

3. Disconnect the machine harness connectors from the ECM.

4. Measure the resistance from the contact J1-13 (wire G808-BU) and contact J1-26 (wire G809-GN) of the machine harness to all contacts that are used in the machine harness connectors for the ECM.

Expected Result:

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

Results:

• OK - The resistance is greater than 5000 ohms. The machine harness is correct. Proceed to test step 5.

• NOT OK - The resistance is NOT correct. There is a short in the machine harness. The short is between wire G809-GN and the circuit with the low resistance measurement or the short is between wire G808-BU and the circuit with the low resistance measurement.

  Repair: Repair the harness or replace the harness.

  Stop.

Test Step 5. CHECK THE SIGNAL CIRCUITS FOR A SHORT TO GROUND.

1. The machine harness remains disconnected from the sensor.

2. The key start switch remains in the OFF position.

3. The machine harness connectors remain disconnected from the ECM.

4. Measure the resistance from the sensor contacts J1-13 (wire G808-BU) and J1-26 (wire G809-GN) to all possible sources of ground.

Expected Result:

The resistance that is measured is greater than 5000 ohms for each measurement.

Results:

• OK - The resistance that is measured is greater than 5000 ohms for each measurement. Proceed to test step 6.

• NOT OK - There is a short in the machine harness.

  Repair: The short is between the wire for the sensor signal and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.

  Stop.

Test Step 6. INSPECT THE SENSOR.

1. The key start switch remains in the OFF position.

2. The sensor remains disconnected from the machine harness.

3. Remove the speed sensor. Inspect the speed sensor for damage or the presence of a foreign material on the tip. Clean the tip. If the sensor is damaged, replace the sensor.

4. Install the speed sensor.

Expected Result:

The sensor is not damaged. The sensor is free of foreign material.

Results:

• OK - The sensor is not damaged. The sensor is free of foreign material. Proceed to test step 7.

• NOT OK - The sensor is damaged or the presence of a foreign material exists.

  Repair: Repair the sensor or replace the sensor.

  Stop.

Test Step 7. CHECK IF THE DIAGNOSTIC CODE REMAINS.

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. Clear all inactive diagnostic codes.

5. Operate the machine.

6. Stop the machine and place the parking brake switch in the ON position.

7. Check if the diagnostic code for the sensor is active.

Expected Result:

The diagnostic code is NO longer active.

Results:

• OK - The diagnostic code is NO longer active. The diagnostic code does not exist at this time. 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.

• NOT OK - The diagnostic code has not been corrected.

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

  Stop.