The FMI 13 diagnostic code is activated after the Machine ECM has been replaced. The calibration process is also recommended after one of the Cat® Grade Control sensors has been replaced.
Multiple position sensors are required for correct operation of the Cat Grade Control system. Each sensor provides an input signal to the Machine ECM that indicates the position of a series of sensors on the machine. The sensors involved in the system are the Boom, Stick, Bucket Position, Tilt Bucket, Front Linkage, Rotation, Body Tilt sensors. Most the sensors receive 24 VDC power via the fuse panel. The position sensing cylinder sensor receives 8 VDC power directly from the Machine ECM. The position sensors send a PWM input signal to the Machine ECM. The bucket position sensing cylinder sends a sign to location J1-49 of the Machine ECM. The PWM position sensors operate at a frequency of approximately 500 ± 80 Hz. The duty cycle of the signal varies from approximately 10 percent at the minimum position to approximately 90 percent at the maximum position.
Note: A specific order must be followed when calibrating the components of the Cat Grade Control system. The Front Linkage sensor must be calibrated first, followed by the Body Tilt Sensor. The remaining sensors for CGC can be calibrated in any sequence preferred.
Test Step 1. CALIBRATION OF FRONT LINKAGE SENSOR (Fine Tune Calibration)
 | |
| Illustration 1 | g02943117 |
- Open the Calibrations sub menu. From the main menu locate and select Service. Within the Service menu locate and select Calibrations. Within the Calibrations submenu locate Fine Tune Front Linkage Calibration and select.
- The technician measures the elevation of Pin A above Pin F.
 | |
| Illustration 2 | g02904537 |
- Enter the value into the operator monitor or Cat ET. The value is used by the Machine ECM (along with programmed boom dimensions) to calculate the actual angle of the front linkage.
- The actual angle and the calculated angle, based on the signal from the rotary sensor, are used to determine an offset angle. The offset angle is used to compensate between the different measurements.
- Follow the instructions provided on the operator monitor.
- The technician should repeat the process above. The process can be repeated up to five times.
- The results of the measurements are averaged to minimize the effects of measurement error.
Expected Result:
The calibration of the Front Linkage sensor was completed successfully.
Results:
- OK - The Front Linkage sensor calibration was completed successfully. Proceed to Test Step 3.
- NOT OK -
Repair: The technician likely made an error when entering a figure. Repeat the calibration process from the beginning.
STOP
Test Step 2. FRONT LINKAGE CALIBRATION (Standard)
If a less exacting measure is required for the operation of the machine, a Standard Front Linkage calibration can be performed. This calibration does not require the technician to make any measurements of the front linkage prior to the start of the calibration process. Consequently, there are also no entries to be made via the operator monitor. During this process, the front linkage will be moved to the full inward position and extended to the maximum position.
- Open the Calibrations sub menu. From the main menu locate and select Service. Within the Service menu locate and select Calibrations. Within the Calibrations submenu locate Front Linkage Calibration and select.
- Follow all instructions listed on the monitor screen during this calibration process.
Expected Result:
The calibration of the Front Linkage sensor was completed successfully.
Results:
- OK - The Front Linkage sensor calibration was completed successfully. Proceed to Test Step 3.
- NOT OK -
Repair: The technician likely made an error when entering a figure. Repeat the calibration process from the beginning.
STOP
Test Step 3. CALIBRATE THE BODY TILT SENSOR
 | |
| Illustration 3 | g02943161 |
The Body Tilt/Angle sensor is located on the body of the cab at the front of the machine. | |
- Open the Cat Grade Control Calibrations sub menu. From the main menu locate and select Service. Within the Service menu locate and select Calibrations. Within the Calibrations submenu locate Cat Grade Control Calibrations. Within the Cat Grade Control Calibrations submenu locate Body Tilt Sensor and select OK.
- The Machine ECM, via the operator monitor, will provide guidance for completion of the calibration.
Expected Result:
The calibration was completed successfully.
Results:
- OK - The calibration was completed successfully. Proceed to Test Step 4.
- NOT OK - An error was likely made by the technician during the calibration process. Repeat the process before moving to the next step. STOP
Test Step 4. CALIBRATE THE BOOM SENSOR
 | |
| Illustration 4 | g02902876 |
The Boom sensor is a rotational sensor that is located at the base of the boom on the left side. | |
- Open the Cat Grade Control Calibrations sub menu. From the main menu locate and select Service. Within the Service menu locate and select Calibrations. Within the Calibrations submenu locate and select Cat Grade Control.
- The technician measures the elevation of Pin B above Pin A.
 | |
| Illustration 5 | g02903799 |
- Enter the value into the operator monitor or Cat ET. The value is used by the Machine ECM (along with programmed boom dimensions) to calculate the actual angle of the boom.
- The actual angle and the calculated angle, based on the signal from the rotary sensor, are used to determine an offset angle. The offset angle is used to compensate between the different measurements.
- Follow the instructions provided on the operator monitor.
- The technician should repeat the process above. The process can be repeated up to five times.
- The results of the measurements are averaged to minimize the effects of measurement error.
Expected Result:
The calibration of the Boom angle sensor was completed successfully.
Results:
- OK - The Boom sensor calibration was completed successfully. Proceed to Test Step5.
- NOT OK -
Repair: The technician likely made an error when entering a figure. Repeat the calibration process from the beginning.
STOP
Test Step 5. CALIBRATE THE STICK SENSOR
| | |
| Illustration 6 | g02902876 |
The Stick sensor is a rotational sensor that is mounted on the left side of the stick arm at the base. | |
- Open the Cat Grade Control Calibrations sub menu. From the main menu locate and select Service. Within the Service menu locate and select Calibrations. Within the Calibrations submenu locate and select Cat Grade Control (CGC).
- The technician measures the elevation of Pin B above Pin G.
 | |
| Illustration 7 | g02903839 |
- Enter the value into the operator monitor or Cat® ET. The value is used by the Machine ECM (along with programmed boom dimensions) to calculate the actual angle of the stick.
- The actual angle and the calculated angle, based on the signal from the rotary sensor, are used to determine an offset angle. The offset angle is used to compensate between the different measurements.
- Follow the instructions provided on the operator monitor.
- The technician should repeat the process above. The process can be repeated up to five times.
- The results of the measurements are averaged to minimize the effects of measurement error.
Expected Result:
The calibration of the Stick Angle sensor was completed successfully.
Results:
- OK - The Stick Angle sensor calibration was completed successfully. Proceed to Test Step 6.
- NOT OK -
Repair: The technician likely made an error when entering a figure. Repeat the calibration process from the beginning.
STOP
Test Step 6. CALIBRATION OF BUCKET SENSOR
| | |
| Illustration 8 | g02902876 |
The Bucket sensor monitors the position of the bucket. The sensor is a position sensor that is located within the bucket cylinder. | |
- Open the Cat Grade Control Calibrations sub menu. From the main menu locate and select Service. Within the Service menu locate and select Calibrations. Within the Calibrations submenu locate and select Cat Grade Control.
- The technician measures the elevation of Pin C above Pin F.
 | |
| Illustration 9 | g02903900 |
- Enter the value into the operator monitor or Cat ET. The value is used by the Machine ECM (along with programmed boom dimensions) to calculate the actual angle of the bucket.
- The actual angle and the calculated angle, based on the signal from the rotary sensor, are used to determine an offset angle. The offset angle is used to compensate between the different measurements.
- Follow the instructions provided on the operator monitor.
- The technician should repeat the process above. The process can be repeated up to five times.
- The results of the measurements are averaged to minimize the effects of measurement error.
Expected Result:
The calibration of the Bucket sensor was completed successfully.
Results:
- OK - The Bucket sensor calibration was completed successfully. Proceed to Test Step 2.
- NOT OK -
Repair: The technician likely made an error when entering a figure. Repeat the calibration process from the beginning.
STOP
Test Step 7. CALIBRATION OF THE ROTATION SENSOR
| | |
| Illustration 10 | g02902876 |
The rotation sensor is used to monitor the position of the machine body in relation to the base of the machine. | |
- Open the Cat Grade Control Calibrations sub menu. From the main menu locate and select Service. Within the Service menu locate and select Calibrations. Within the Calibrations submenu locate and select Cat Grade Control.
- The Machine ECM, via the operator monitor, will provide guidance for completion of the calibration.
Expected Result:
The calibration was completed successfully.
Results:
- OK - The calibration was completed successfully. Proceed to Test Step 4.
- NOT OK - An error was likely made by the technician during the calibration process. Repeat the process before moving to the next step.STOP