SPROCKET 1903895 - Caterpillar

Illustration 1 g02016553
Schematic of the pressure sensor (right parking brake oil)
This diagnostic code is associated with the pressure sensor (right parking brake oil). The FMI 03 diagnostic code means that the ECM has determined that the voltage of the circuit for the sensor is above normal. Refer to Systems Operation, "Sensors" for information regarding the operation of the sensor and the location.The pressure sensor is a PWM sensor with an operating duty cycle from 0% to 100%. The sensor has an operating pressure range from 0 kPa (0 psi) to 5871 kPa (852 psi). The relation between the pressure and the duty cycle is linear.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 situation 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 1226 FMI 03 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:The diagnostic code will be logged into memory.Test Step 1. CHECK FOR POWER AT THE SENSOR.
Do not disconnect the harness connector from the sensor.
Turn the key start switch and the disconnect switch to the ON position.
At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along the voltage supply wire (contact A).
Measure the voltage from contact A to frame ground. Expected Result:The voltage is +24 VDC.Results:
OK - The voltage is +24 VDC. Proceed to Test Step 2.
NOT OK - The voltage is not +24 VDC. The + battery circuit in the machine harness has failed.Repair: Replace the machine harness or repair the machine harness.STOPTest Step 2. 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 the 7X-1710 Multimeter Probe from the voltage supply wire (contact A).
At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along the ground wire (contact B).
Measure the resistance from contact B to frame ground. Expected Result:The resistance is less than 5 ohms.Results:
OK - The resistance is less than 5 ohms. The ground circuit is correct. Proceed to Test Step 3.
NOT OK - The resistance is greater than 5 ohms. The ground circuit in the machine harness has failed.Repair: Replace or repair the machine harness.STOPTest Step 3. CHECK THE WIRING HARNESS OF THE SENSOR FOR AN OPEN CIRCUIT.
The key start switch and the disconnect switch remain in the OFF position.
Disconnect the machine harness from the sensor.
At the harness connector for the sensor, connect a jumper wire between contact B and contact C.
Disconnect the machine harness connectors from the ECM.
At the harness connector for the ECM, measure the resistance between