LEG 2P3854 - Caterpillar

Illustration 1 g01927571
Schematic of the circuit for the hydraulic load sensor
This diagnostic code is associated with the hydraulic load. The FMI 03 diagnostic code means that the Machine ECM determined that the sensor signal voltage is too high. The possible causes of this diagnostic code are listed below:
The sensor has failed.
The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted high to the +battery.
The signal circuit in the machine harness is open or the sensor is disconnected.
The Machine ECM has failed. A failure of the Machine ECM is unlikely. Test Step 1. CHECK THE SENSOR POWER.
Turn the disconnect switch and the key start switch to the ON position.
Insert the 7X-1710 Multimeter Probe leads into the back of the sensor connector along side of contact A (wire 147-PU(Purple)) and contact B (wire A209-BK(Black)).
Measure the voltage (DCV) between signal contact A (wire 147-BK(Black)) and ground contact B (wire A209-BK(Black)). Expected Result:The voltage is 24 DCV.Results:
OK - The voltage is 24 DCV . The system voltage is correct. Proceed to Test Step 2.
NOT OK - The voltage is NOT 24 DCV. There is an open circuit. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE SIGNAL VOLTAGE.
Insert the 7X-1710 Multimeter Probe leads into the back of the sensor connector along side of contact C (wire P936-GY(Grey)) and contact B (wire A209-BK(Black)).
Measure the signal voltage and record the signal voltage. Expected Result:The signal voltage is between approximately .7 DCV and 24.0 DCV. Results:
.7 DCV TO 24.0 DCV. - The signal voltage at the sensor is correct. Proceed to Test Step 3.
> 6.0 VDC. - The voltage is NOT between .7 DCV and 24.0 DCV. The signal voltage is not correct. Proceed to Test Step 3.Test Step 3. CHECK THE SIGNAL CIRCUIT OF THE MACHINE HARNESS.
Insert the 7X-1710 Multimeter Probe leads into the back of the machine harness connector along side of the signal contact C (wire P936-GY(Grey)) and ground circuit wires.
At the machine harness connector for the sensor, measure the voltage between signal contact C (wire P936-GY(Grey)) and ground contact B (wire A209-BK(Black)).
Compare this measurement with the voltage that was measured in the previous test “CHECK THE SIGNAL VOLTAGE”. Expected Result:The signal voltage is equal to the voltage that was recorded in the previous test.Results:
OK - The signal voltage is equal to the voltage that was recorded in the previous test. The ECM is receiving a valid signal voltage. The ECM has failed.Repair: A failure of the ECM is unlikely. Exit this procedure and perform the CID 2997 FMI 03 procedure again. If the fault is not found, replace the ECM. See the Testing and Adjusting, "Electronic Control Module (ECM) Replace" section in this manual. STOP
NOT OK - The signal voltage is NOT equal to the voltage that was recorded in the previous test. The machine harness has an open in the signal or ground circuits.Repair: Repair the machine harness or replace the machine