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| Illustration 1 | g02731146 |
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Schematic of the "Left Final Drive Pressure" sensor | |
This diagnostic code is associated with the "Left Final Drive Pressure" sensor. The FMI 08 diagnostic code means that the Brake ECM has determined that the signal output from the sensor is above normal. The FMI 08 diagnostic code is used to indicate that the output of the frequency or that the pulse width of the sensor is abnormal. Refer to Systems Operations, "Sensors" for more information regarding the operation of the sensor and the location.
The possible causes of this diagnostic code are listed below:
- Intermittent connections or poor connections
- The sensor has failed.
- A mechanical device is loose.
- The Brake ECM has failed. This situation 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 3021 FMI 08 is active before performing this procedure.
Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.
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When it is necessary to work under the machine with the body (bed) raised, attach the body (bed) retaining cables to the rear tow points. Install the rear tow point pins through the ends of the retaining cables. Failure to properly secure the body (bed) may result in personal injury or death. |
Test Step 1. CHECK FOR POWER AT THE SENSOR
- Do not disconnect the harness connector from the sensor.
- At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe at contact A (wire A700-OR(Orange)).
- Turn the key start switch and the disconnect switch to the ON position.
- Measure the voltage from contact A to the frame ground.
Expected Result:
The voltage is 8 VDC.
Results:
- OK - The voltage is 8 VDC. Proceed to Test Step 2.
- NOT OK - The voltage is not 8 VDC. The circuit is open.
Repair: Repair or replace the machine harness.
STOP
Test Step 2. CHECK THE SIGNAL CIRCUIT OF THE SENSOR
- Turn the key start switch and the disconnect switch to the OFF position.
- At the back of the harness connector for the sensor, remove the 7X-1710 Multimeter Probe from contact A and insert the probe along the signal wire at contact C (wire H919-OR(Orange)).
- At the back of the harness connector for the sensor, insert the 7X-1710 Multimeter Probe along the ground wire at contact B (wire C243-BK(Black)).
- Turn the disconnect switch and the key start switch to the ON position.
- Monitor the signal of the sensor with the 146-4080 Digital Multimeter.
- Without disconnecting the sensor or the hardware that is associated with the sensor from the machine, take the sensor through the full operating range.
Note: On some machines, starting the engine may be necessary to take the sensor through the full operating range.
Expected Result:
The signal of the sensor responds in the manner that is described at the beginning of this procedure.
Results:
- OK - The signal from the sensor is responding correctly. Proceed to Test Step 3.
- NOT OK - The signal from the sensor 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
- Turn the key start switch and the disconnect switch to the OFF position.
- Insert the 7X-1710 Multimeter Probe into the back of the ECM connector along pin J2-43 (wire H919-OR(Orange)) and pin J1-45 (wire C243-BK(Black)).
- Turn the key start switch and the disconnect switch to the ON position.
- Monitor the signal of the sensor with the 146-4080 Digital Multimeter.
- Without disconnecting the sensor or the hardware that is associated with the sensor from the machine, take the sensor through the full operating range.
Note: On some machines, starting the engine may be necessary to take the sensor through the full operating range.
Expected Result:
The signal of the sensor responds in the manner that is described at the beginning of this procedure.
Results:
- OK - The signal from the sensor is responding correctly. Proceed to Test Step 4.
- NOT OK - The signal from the sensor does not respond correctly. The harness has failed.
Repair: Repair or replace the machine harness.
STOP
Test Step 4. CHECK THE SIGNAL CIRCUIT FOR A SHORT IN THE HARNESS
- The key start switch and the disconnect switch remain in the OFF position.
- Disconnect the machine harness connectors from the sensor and the Brake ECM.
- Measure the resistance between contact J2-43 (wire H919-OR(Orange)) and all of the contacts that are used in the machine harness connectors for the Brake 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 or replace the machine harness.
STOP
Test Step 5. CHECK IF THE DIAGNOSTIC CODE REMAINS
- Inspect the harness connections and clean the contacts of the harness connections of the machine.
- Reconnect all harness connections.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Check the status of the CID 3021 FMI 08 diagnostic code.
Expected Result:
The CID 3021 FMI 08 diagnostic code is not active.
Results:
- OK - The CID 3021 FMI 08 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 . Resume normal operation.
STOP
- NOT OK - The CID 3021 FMI 08 diagnostic code is active. The diagnostic code has not been corrected. The Brake ECM may have failed.
Repair: A failure of the ECM is unlikely. Exit this procedure and perform this procedure again. Prior to replacing an ECM, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP