PUMP GP-PS- 1678108 - Caterpillar

Test Step 1. CHECK THE SENSOR POWER SUPPLYNote: Before performing this test step, verify that the power fuse for the sensor is not open. If the fuse is open, replace the fuse and verify that this diagnostic code is still active before proceeding.
Turn the key start switch and the disconnect switch to the ON position.
At the machine harness connector for the sensor, insert 7X-1710 Multimeter Probes along the contact for the power supply A (wire 156-YL(Yellow)) and along ground contact B (wire P967-PU(Purple)).
Measure the system voltage.
Remove the multimeter probe from along the ground contact and make a good contact with frame ground.
Measure the system voltage. Expected Result:Both of the voltage measurements are at the system voltage level.Results:
OK. - Both of the voltage measurements are at the system voltage level. The sensor is receiving system voltage. Proceed to Test Step 2.
NOT OK. - One of the voltage measurements or both of the voltage measurements are not at the voltage level of the system. The sensor is not receiving system voltage. Repair: If both of the voltage measurements are not measuring system voltage, it is likely that the power circuit between the fuse and the position sensor is an open connection or that the sensor has a poor connection in the machine harness.If the voltage measurement between the power circuit and the ground circuit is not measuring system voltage and the voltage measurement between the power circuit and frame ground is measuring system voltage, the ground circuit between the ECM and the position sensor is most likely an open connection or the sensor has a poor connection.Refer to the complete Electrical System Schematic of the machine. Examine all of the connections and the wires that are in the suspect circuit for open connections or poor connections. Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK FOR AN OPEN IN THE SENSOR CIRCUIT
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector from the position sensor.
At the machine harness connector for the sensor, place a jumper wire between the return contact of the sensor B (wire P967-PU(Purple)) and the signal contact C (wire H787-GN(Green)) .
Disconnect machine harness connectors J1 and J2 from the Implement ECM.
At the harness connectors for the ECM, measure the resistance from return contact J1-45 (wire P967-PU(Purple)) to signal contact J2-43 (wire H787-GN(Green)). Expected Result:The resistance measurement is less than 5 ohms.Results:
OK. - The resistance measurement is less than 5 ohms. The sensor circuit is not open. Proceed to Test Step 3.
NOT OK. - The resistance measurement is greater than 5Ω. There is an open connection or a bad connection in the signal circuit.Repair: A resistance measurement that is greater than 5kΩ could indicate that a wire is not connected or that a wire is open. A resistance measurement that is greater than 5Ω but less than 5kΩ could indicate that one of the connection points in the circuit is not an open connection but that connection