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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine. |
Operation and Maintenance Manual, SEBU9099, "Prepare the Machine for Maintenance"
Operation and Maintenance Manual, SEBU9099, "Operator Controls"
Operation and Maintenance Manual, SEBU9099, "Use of Wheel Chocks"
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| Illustration 1 | g02451337 |
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Typical view of rod linkage (1) Rod end (2) Nut (3) Rod (4) Body position sensor (5) Center of the rod ends | |
The calibration procedure for body position sensor (4) must be performed when one or more of the following conditions occur:
- A new truck is being assembled.
- A new position sensor is installed.
- The Electronic Control Module (ECM) is replaced.
- The body is replaced.
Body position sensor (4) is located near the pivot pin for the body. A lever is attached between the sensor and the body. When the body is raised or lowered, the lever rotates the sensor. This action changes the Pulse Width Modulation (PWM) signal that is sent to the "Chassis" ECM.
If the expected PWM signal does not occur, then the "Chassis" ECM generates an event code. The code is logged toVIMSTM.
The following conditions must be met for 12 seconds:
- The engine is running with no ground speed.
- The payload is zero.
- The hoist control lever must be in FLOAT mode.
- The duty cycle output is within the range of 3 to 30 percent.
Note: The recommended duty cycle output is within the range of 14 to 19 percent.
The following occurs when all the conditions are met for 12 seconds:
- The calibration value will be the average of the values that were recorded during that 12 seconds.
When the bed is fully lowered, the "Chassis" ECM expects a value that is greater than 1 percent PWM.
If the expected PWM value is not obtained, then an FMI 04 will be logged. If this event occurs, then perform the "Rod Adjustment" in the "Adjustment Procedure" section.
The standard range for the calibration limits is plus or minus 2 percent of the last calibration point. If the tolerance range is not exceeded, then the lower calibration point will not change.
If the tolerance range is exceeded, then the upper calibration point will default to a 50 percent duty cycle until the upper calibration is performed. The lower calibration point will change to the average value over the last 12 seconds.
This change occurs because there has been a mechanical change in the system that measures the output of the sensor. For example, a change could occur under any of the following conditions:
- The nuts that secure the adjustment rod are loose.
- There is excessive wear on the body pins.
- The adjustment rod is bent or damaged.
- The sensor is damaged.
Any of these conditions could affect the duty cycle of the full lower calibration.
The following conditions must be met for 500 milliseconds:
- The engine is running with no ground speed.
- The duty cycle output is in a range of 50 to 95 percent.
- The current full up duty cycle must be greater than the previous full up duty cycle.
- The hoist control lever must be in RAISE mode or in HOLD mode.
Note: When the bed has reached the maximum height, the operator should move the hoist lever from the RAISE position to the HOLD position. Five seconds after the hoist lever is in position the calibration will begin.
The following occurs when all the conditions are met for 500 milliseconds:
- The calibration value will be the average of the values that were recorded during the 500 milliseconds.
- If the current upper calibration value is less than the previous upper calibration value, then the value will not change.
When the bed is fully raised, the Chassis ECM expects a value of less than 96 percent PWM.
If the expected PWM value is not obtained, then an FMI 03 will be logged. If this event occurs, then perform the "Rod Adjustment" in the "Adjustment Procedure" section.
The following issues could prevent calibration of the position sensor. The issues could cause sensor diagnostics to be logged.
Wear on the body pins could cause the position sensor to provide an incorrect value. This value could cause diagnostic faults to register against the sensor.
If the body pins are worn, perform the "Rod Adjustment" in the "Adjustment Procedure". Verify that the angle of the body is less than 7 degrees when the body is fully lowered.
If the body does not drop fully to the frame rails, perform the following:
- Adjust the "Hoist Lower Valve Adjustment Status" value with Cat® Electronic Technician (Cat® ET).
- Perform a body up/ body down cycle.
- Continue to adjust the "Hoist Lower Valve Adjustment Status" value until the desired snubbing is obtained.
The following adjustment may be required for the "Chassis" ECM to calibrate the position sensor:
- Disconnect rod (3) from the body.
- Loosen nut (2) on rod (3).
- Twist the rod (3) to get a distance of
360 ± 3 mm (14.2 ± 0.1 inch) between the centers of the rod ends (5). - Tighten nut (2).
- Reattach rod (3) to the body.
Verify that the angle of the body is within tolerance when any of the following components are replaced:
- A Sensor
- A Body
- An ECM
Note: If the angle is not within tolerance, then the "Chassis" ECM cannot correctly calibrate the position sensor.
Lower the body to the frame rails. If the value is less than 7 degrees, the software in the "Chassis" ECM calibrates the sensor. The calibration is performed automatically by the "Chassis" ECM when the body is raised and lowered. If the value is not less than 7 degrees, then perform the "Rod Adjustment" in the "Adjustment Procedure" section.