ELBOW GP-EXHAUST 1746487 - Caterpillar

Illustration 1 g01079534
Schematic for hydraulic sensorThis diagnostic code is associated with the hydraulic sensor (pressure). The FMI 01 means that the ECM has determined that the signal of the sensor is below the normal range. The possible causes of this failure are listed below:
The position sensor has failed.
The signal circuit of the sensor is shorted to the ground.
The sensor needs to be calibrated.
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.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:When this diagnostic code is active the hydraulic control system will default to the "Auto Not Allowed" state.Test Step 1. INSPECT THE SENSOR.
Perform a visual inspection of the sensor, the wiring for the sensor and the hardware that is associated with the sensor.Expected Result:There is no apparent damage to the sensor, the wiring for the sensor or the hardware that is associated with the sensor.Results:
OK - There is no apparent damage to the sensor, the wiring for the sensor or the hardware that is associated with the sensor. Proceed to Test Step 2.
NOT OK - There is apparent damage to the sensor, the wiring for the sensor or the hardware that is associated with the sensor. Repair: Replace the damaged part.STOPTest Step 2. 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 A".
Turn the key start switch and the disconnect switch to the ON position.
Measure the voltage from "contact A" to frame ground.Expected Result:The voltage is 5 DCV.Results:
OK - The voltage is 5 DCV. Proceed to Test Step 3.
NOT OK - The voltage is not 5 DCV. The circuit is open. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK FOR PROPER GROUND AT THE SENSOR.
The machine harness remains connected to the sensor.
Turn the key start switch and the disconnect switch to the OFF position.
Remove