COUPLING GP-GENERATOR 2500792 - Caterpillar

Illustration 1 g00795166
Schematic of the Position Sensor (Elevator Control) This diagnostic code is associated with the Position Sensor (Elevator Control). The FMI 08 means that the ECM has determined that the signal frequency or the signal pulse width is not within the expected range. The output frequency of the position sensor is approximately 500 hertz. The duty cycle of the signal changes as the position sensor moves. Elevator Forward - 5 percent to 35 percent duty cycleElevator Neutral - 40 percent to 60 percent duty cycleElevator Reverse - 65 percent to 95 percent duty cycle 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 1284 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 occurs, a warning (Category 1) is shown on the monitor. The diagnostic code will cause the solenoids for the elevator control to be set to the minimum command. Control of the elevator will not return until the diagnostic code is inactive. The signal from the position sensor must be in the neutral position for at least two seconds.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 along the voltage supply wire (contact 1).
Turn the key start switch and the disconnect switch to the ON position.
Measure the voltage from contact 1 to frame ground.Expected Result:The voltage is 24 DCV.Results:
OK - The voltage is 24 DCV. Proceed to Test Step 3.
NOT OK - The voltage is not 24 DCV. The circuit is open. Repair: Repair the machine harness 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 1 and insert the probe along the signal wire (contact 3).
At the back of the harness connector for the sensor, insert the 7X-1710 Multimeter Probe along the ground wire (contact 2).
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 of the sensor.Note: On some machines, it may be necessary to start the engine in order to take the sensor through the full operating range of the sensor.Expected Result:The sensor's signal responds in the manner that is described at the begining of this procedure.Results:
OK - The sensor's signal responds correctly.