ROD AS 1294449 - Caterpillar

Illustration 1 g01659774
Schematic of the Position Sensor (Boom Cylinder)This diagnostic code is associated with the position sensor (Boom Cylinder). The FMI 03 diagnostic code means that the ECM has determined that the voltage of the circuit for the sensor is above normal. The position sensor is a pulse width modulated sensor that operates at a frequency of approximately 500 hertz.The possible causes of this diagnostic code are listed below:
The signal circuit for the sensor is open.
The signal circuit for the sensor is shorted to the +battery circuit.
The sensor has failed.
The power circuit or the ground circuit has failed.
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 1959 FMI 03 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:A level 1 warning is generated.The diagnostic code of CID 1959 FMI 03 will be logged in the internal memory of the ECM.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 contact 1 (wire 799-WH) for the voltage supply.
Turn the key start switch and the disconnect switch to the ON position.
Move the linkage through the full range of motion. Observe that the multimeter remains connected to contact 1 (wire 799-WH). Ensure proper readings while the linkage is in motion. Observe that the other probe of the multimeter remains connected to contact 2 (wire J766-PU).
Measure the voltage from contact 1 (wire 799-WH) to contact 2 (wire J766-PU).Expected Result:The voltage is 10 Volts DC.Results:
OK - The voltage is 10 Volts DC. Proceed to Test Step 3.
NOT OK - The voltage is not 10 Volts DC. The circuit is not correct. It is likely that the faulty reading is caused by damage to the machine harness.Repair: Repair the machine harness or replace the machine harness.STOPTest 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 .
Do not disconnect the sensor or the hardware that is associated with the sensor from the machine. Move the sensor through the full operating range.
At the back of the harness connector for the sensor, remove the 7X-1710 Multimeter Probe from contact 3 and test the signal at the sensor.Expected Result: